Crank Ventilation System
6.0L Diesel Engine
Closed Crankcase Ventilation (CCV) System
The Closed Crankcase Ventilation (CCV) system
route’s crankcase blow-by gases from the breather assembly back into the engine
intake airflow to be used for combustion.
6.4L Diesel Engine
Closed Crankcase Ventilation (CCV) System
The Closed Crankcase Ventilation (CCV) system
route’s crankcase blow-by gases from the breather assembly back into the engine
intake airflow to be used for combustion.
6.7L Diesel Engine
Crankcase Ventilation
The crankcase ventilation system, Fig. 43, purges crankcase
gases to the intake manifold. The crankcase ventilation system consists of five
main elements, (1) expansion chamber separator, (2) cyclonic oil separator unit
w/integral pressure limiting valve, (3) stainless steel check valve, (4) oil
collection chamber and (5) pressure regulating valve.
Fig. 43 Crankcase ventilation system operation. Ford 6.7L
diesel engine
Combustion blow-by gases enter the rear port of crankcase
vent assembly and pass into an expansion chamber where larger oil droplets fall
out of blow-by gases due to a rapid decrease in flow velocity. The remaining
blow-by gases flow through into cyclonic oil separator unit. The blow-by gases
are then separated into smaller cyclone oil separators, which force smaller oil
droplets to the side walls, so they drain out and flow to oil collection
chamber. The remaining lighter gases flow to the intake manifold.
The oil collection chamber has a drain port and a stainless
steel check valve. The check valve allows smaller oil droplets to return to
crankcase while blocking gases in the oil return path. The oil separator works
using cyclonic technology. Therefore, no filter media is required inside
canister. There is an integrated pressure regulating valve on the side of the
cyclonic oil separator which prevents excessive vacuum levels from being
applied to crankcase. Maintenance is not required, and canister is replaced as
an assembly.
Diesel Exhaust Fluid (DEF) System
6.7L Diesel Engine
Reductant Heater & Sender Assembly
The reductants heater and sender assembly contains a pickup
tube for reductants pump module, an electric heating element, a reductant’s
temperature sensor and an electrode type level sensor. The heating element is
directly above pick-up-tubes inlet filter. When the reductant’s temperature
sensor detects the diesel exhaust fluid temperature dropping to the freezing
point of 12°F (-11°C), the PCM will command the glow plug control module to
provide voltage to heating element. The heating element thaws liquid reductants
within the reductants heater and sender assembly reservoir during cold ambient
temperatures.The reductants level sensor incorporates four stainless
steel electrodes, with three electrodes arranged vertically to provide a high,
middle, and low level signal. The fourth electrode acts as a ground. When the
reductant’s tank is full, DEF closes a circuit between all three-level
electrodes and ground electrode, indicating tank is full. As DEF is consumed,
level drops and uncovers each electrode in sequence. The PCM calculates DEF
level based on these signals.
Reductant Heaters
The reductant heaters maintain DEF in a liquid state during
cold ambient temperatures. There are three heating elements in the system, each
receiving voltage from the glow plug control module. The reductant tank heater
is integral to the reductant heater and sender assembly. The reductant pump
heater is integral to the reductant pump assembly.
Reductant Injector
The reductant injector, Fig. 44, is a pulse width modulated
solenoid controlled directly by PCM. The injector receives DEF from reductant
pressure line and sprays it into the exhaust stream, where it is mixed into
exhaust gases before entering SCR catalyst.
Fig. 44 Reductant injector components & location. Ford
6.7L diesel engine
Reductant Pressure Sensor
The reductant pressure sensor provides feedback to PCM, which
regulates system pressure by controlling pump speed using pulse width
modulation. The reductant pressure sensor is integral to the reductant pump
assembly.
Reductant Pump Assembly
The reductant pump assembly contains a diaphragm pressure
pump, a pressure sensor, a purge valve, an outlet filter and an internal
heating element. The reductant pressure sensor provides feedback to PCM, which
regulates system pressure by controlling pump speed using pulse width
modulation. When PCM request’s reductant injection, the reductant injector
opens and the pump operates, filling reductant pressure line and injector and
purging air from the system. When all air is purged, injector closes and pump
builds pressure to 73 psi. (500 kPa). The system is then primed, and injector
provides DEF to the SCR catalyst as determined by PCM.
When the vehicle is shut down, PCM closes injector and
actuates reductant purge valve, causing the pump to reverse flow and bleed down
pressure on reductant pressure’s lines. The PCM then opens injector to allow
gas to enter reductant pressure line, which in turn allows the pump to purge
all remaining DEF from the system and return it to the reductant tank. The PCM
closes injector, and returns purge valve to the forward position. The PCM
commands the glow plug control module to provide voltage to the reductant pump
assembly internal heating element when reductant temperature approaches 12°F
(-11°C).
Reductant Purge Valve
The reductant purge valve allows the reductant pump assembly
to reverse flow and purge system when requested by PCM. The reductant purge
valve is integral to the reductant pump assembly.
Diesel Oxidation Catalyst (DOC)
6.0L & 7.3L Diesel Engines
Description
The purpose of the exhaust catalyst and exhaust system, Fig.
29, is to convey the exhaust gas from the engine to the atmosphere and reduce
the tailpipe emissions of hydrocarbon (HC), carbon monoxide (CO), oxides of
nitrogen (NOx) and diesel particulates.
The exhaust gas and particulates are directed away from the
engine through the exhaust manifold. The exhaust gas concentrations are then
reduced to acceptable levels as the exhaust gas passes through the Diesel
Oxidation Catalyst (DOC). Since the particulates are components of the exhaust
gas, some soot particulates may deposit on the DOC. The reduced emissions
exhaust gas, and any remaining particulates flow through the muffler and
tailpipe into the atmosphere.
The converter body should be inspected for distortion and
other types of damage. Excessive heat can bulge or distort the converter or
filter. Furthermore, inspect for missing or improperly installed converter heat
shields.
Diesel Particulate Filter (DPF)
6.4L Diesel Engine
Diesel Particulate Filter (DPF)
The DPF, Fig. 45, collects soot and ash particles that are
present in exhaust gas of diesel engines. The DPF assembly typically consists
of active precious metals deposited on a substrate filter. The exhaust gas is
forced to flow through walls of porous substrate and exit through adjoining
channels. The particulates that are larger than pore size of walls are trapped
for regeneration. During regeneration temperature in DPF increases to be
greater than 1022°F (550°C); at this temperature, soot in DPF burns and becomes
ash. The precious metal coating promotes regeneration of trapped particulates
through heat generating reaction and catalyzes untreated exhaust gas. The
substrate filter is held in the metal shell by a ceramic fiber support system.
The support system makes up size differences that occur due to thermal
expansion and maintain a uniform holding force on substrate filter.
Fig. 45 Catalytic Oxidation Catalyst (DOC), Diesel
Particulate Filter (DPF) & exhaust system. Ford 6.4L diesel engine.
Diesel Particulate Filter (DPF) Pressure Sensor
The DPF pressure sensor is an input to PCM and is used to
measure pressure before DPF. The sensor is a differential type sensor that is
referenced to atmospheric pressure. At key On, engine Off DPF pressure sensor
pressure value reads 0 psi. (0 kPa). The range of the sensor is 0 to 11.6 psi.
(0 to 80 kPa).
The converter body and diesel particulate filter should be
inspected for distortion and other types of damage. Excessive heat can bulge or
distort the converter or filter. Furthermore, inspect for missing or improperly
installed converter heat shields.
6.7L Diesel Engine
Diesel Particulate Filter (DPF)
The diesel particulate filter, Fig. 46, collects soot and
ash particles that are present in exhaust gas of diesel engines. The diesel
particulate filter assembly typically consists of active precious metals
deposited on a substrate filter. The exhaust gas is forced to flow through
walls of porous substrate and exit through adjoining channels. The particulates
that are larger than pore size of walls are trapped for regeneration. During
regeneration temperature in DPF increases to be greater than 1022°F (550°C).
The precious metal coating promotes regeneration of trapped particulates
through heat generating reaction and catalyzes untreated exhaust gas. The
substrate filter is held in a metal shell by a ceramic fiber support system.
The support system makes up size differences that occur due to thermal
expansion and maintains a uniform holding force on the substrate filter.
Fig. 46 Diesel Particulate Filter (DPF). Ford 6.7L diesel engine
The converter body and diesel particulate filter should be
inspected for distortion and other types of damage. Excessive heat can bulge,
distort the converter, or filter. Furthermore, inspect for missing or
improperly installed converter heat shields.
Diesel Particulate Filter (DPF) Pressure Sensor
The dieselparticulate filter pressure sensor is an input to
CM, and measures pressure before DPF. The sensor is a differential type sensor
that is referenced to atmospheric pressure and is located in the exhaust system
downstream of DPF. At key On, engine Off, the DPF pressure sensor pressure
value reads 0 psi. (0 kPa). The range of the sensor is 0 to 11.6 psi (0 to 80
kPa). The PCM calculates the soot load based on DPF pressure and initiates
regeneration when the soot load reaches the specified limit.
EGR System
Diesel
Engine EGR Valve System
With engine at normal operating temperature, vacuum should be applied to EGR valve at idle speed.
- Ensure all vacuum hoses are properly routed,
securely attached and undamaged. - Disconnect and plug EGR vacuum supply hose at
EGR valve. - Connect a suitable hand held vacuum pump to
EGR valve vacuum port, then gradually apply 12 inches of vacuum. - Observe vacuum gauge on vacuum pump for loss
of vacuum. If a loss is present, replace EGR valve. - Release vacuum from EGR valve and listen for
sound of valve hitting seat.
6.0L Diesel Engine
EGR Valve
The EGR system reduces peak combustion temperatures and NOx.
The EGR valve, Fig. 47, is an electromechanical device that uses a linear
actuator to control relative position of the valve pintle. This device also has
a built-in pintle position sensor that functions to provide PCM with a feedback
signal.
Fig. 47
EGR valve location. Ford 6.0L diesel engine
Inspect the system for proper installation of EGR valve,
control switches, and sensors. Inspect for proper connection of electrical
connectors and mechanical linkage.
EGR Actuator & Valve Position Sensor
The EGR actuator is a variable position valve that controls
the amount of exhaust that enters the intake manifold. The EGR actuator is
controlled by PCM using a pulse width modulated signal that varies from 0-100%.
The EGR actuator consists of two components, a valve with an actuator and a
position sensor to monitor valve movement. The EGR valve position sensor is a
potentiometer sensor, which is needed to give control circuit feedback to
achieve the desired travel position. When the EGR receives a 5 volt reference
signal and a ground from PCM, a linear analog voltage signal from the sensor indicates
the position of EGR valve. Input signals from manifold absolute pressure,
exhaust pressure, and BARO sensors are used by PCM to determine EGR system
flow.
EGR System Cooler
The exhaust gasses are directed through EGR system cooler to
remove heat before gasses arrive at EGR valve. Engine coolant is used to reduce
exhaust gas temperature by directing coolant flow through the EGR system
cooler.
EP Sensor
The EP sensor is a variable capacitor sensor that is
supplied a 5 volt reference signal by PCM and returns a linear analog voltage
signal that indicates pressure. The EP sensor measures pressure in the LH
exhaust manifold. The sensor feedback signal is used for VGT and EGR valve
control.
6.4L Diesel Engine
Exhaust Gas Recirculation (EGR) Oxidation Catalytic
Converter (OC)
The EGR OC, Fig. 48, helps keep EGR coolers clean by
removing deposits and exhaust condensation and preventing corrosion in
downstream components.
Fig. 48 Exhaust Gas Recirculation (EGR) Oxidation Catalytic
Converter (OC). Ford 6.4L diesel engine
Exhaust Gas Recirculation (EGR) Coolers
The exhaust gasses are directed through two EGR coolers,
Fig. 49, to remove heat before gasses arrive at EGR valve. Engine coolant is
used to reduce exhaust gas temperature by directing coolant flow through EGR
coolers.
Fig. 49 Exhaust Gas Recirculation (EGR) coolers. Ford 6.4L
diesel engine
Exhaust Gas Recirculation Temperature (EGRT) Sensor
The EGRT sensor is a thermistor device that monitors exhaust
gas temperature before EGR coolers. The electrical resistance of a thermistor
decreases as temperature increases and increases as the temperature decreases.
The varying, non-linear resistance affects voltage drop across sensor terminals
and provides an electrical signal to PCM that corresponds to measured
temperature. The EGRT sensor is used to determine whether EGR coolers are
operating correctly.
Exhaust Gas Recirculation Temperature 2 (EGRT2) Sensor
The EGRT2 sensor is a thermistor device that monitors
exhaust gas temperature after EGR coolers. The electrical resistance of a
thermistor decreases as temperature increases and increases as the temperature
decreases. The varying, non-linear resistance affects voltage drop across
sensor terminals and provides an electrical signal to PCM that corresponds to
measured temperature. The EGRT2 sensor is used to determine whether EGR coolers
are operating correctly.
Exhaust Gas Recirculation (EGR) Valve
The EGR valve is a variable position valve that controls the
amount of exhaust that enters the intake manifold. The PCM controls the EGR
valve, which operates between -100 and 100% duty cycles, which cannot be viewed
by a scan tool.
Exhaust Gas Recirculation (EGR) Valve Position Sensor
The EGR valve position sensor is a potentiometer sensor that
monitors EGR valve movement. The valve position signal is monitored for the
desired EGR valve travel position. The sensor is integral to EGR valve.
6.7L Diesel Engine
EGR Cooler
The EGR cooler, Fig. 50, removes heat from exhaust gases
before gases enter the intake manifold. The EGR cooler is located above RH
valve cover. When exhaust gases are directed through EGR cooler, coolant from
the secondary cooling system reduces exhaust gas temperature. The exhaust gases
are directed through EGR cooler by a PCM controlled EGR cooler bypass valve.
Fig. 50 EGR cooler. Ford 6.7L diesel engine
EGR Cooler Bypass Valve
The exhaust gases are directed through an EGR cooler by EGR
cooler bypass valve, Fig. 51, to remove heat before entering intake manifold.
The EGR cooler bypass valve is internal to EGR cooler and mounted to RH valve
cover, below EGR valve. When EGR cooler bypass valve solenoid is commanded to
0% duty cycle by PCM, EGR cooler bypass valve is closed. When EGR cooler bypass
valve is closed, exhaust gases pass through EGR cooler to the intake manifold.
When EGR cooler by pass valve solenoid is commanded to 100% duty cycle by PCM,
EGR cooler bypass valve is opened. When EGR cooler bypass valve is open,
exhaust gases pass directly to the intake manifold without passing through EGR
cooler.
Fig. 51 EGR cooler bypass valve. Ford 6.7L diesel engine
EGR Cooler Bypass Valve Solenoid
The EGR cooler bypass valve solenoid is a PCM controlled
vacuum solenoid. The EGR cooler bypass valve solenoid controls EGR cooler
bypass valve position by applying vacuum from the vacuum pump to EGR cooler
bypass valve actuator. The EGR cooler bypass valve solenoid is located at the
top front of EGR cooler. When the EGR cooler bypass valve solenoid is commanded
to 0% duty cycle by powertrain control module (PCM), no vacuum from the vacuum
pump is applied to EGR cooler bypass valve actuator and EGR cooler bypass valve
is closed. When EGR cooler bypass valve is closed, exhaust gases pass through
EGR cooler to the intake manifold. When EGR cooler bypass valve solenoid is
commanded to 100% duty cycle by PCM, vacuum from the vacuum pump is applied to
EGR cooler bypass valve actuator and the EGR cooler bypass valve is opened.
When the EGR cooler bypass valve is open, exhaust gases pass directly to the
intake manifold without passing through EGR.
Exhaust Gas Recirculation Temperature (EGRT) Sensor
The EGRT sensor is a thermistor type sensor. The EGRT sensor
is an input to PCM and monitors the exhaust gas temperature after EGR cooler.
The electrical resistance of the sensor increases as temperature decreases and
resistance decreases as temperature increases. The varying resistance changes
voltage drop across sensor terminals and provides electrical voltage to PCM
corresponding to temperature. The EGRT sensor is used to determine if EGR
cooler is operating properly.
EGR Valve
The EGR valve is a variable position valve that controls the
amount of exhaust that enters the intake manifold. The PCM controls EGR valve,
which operates between 0 and 100% duty cycles. The EGR valve operation can be
monitored by viewing EGRVP PID, which displays EGR valve position. The EGR valve
position sensor is integral EGR valve.
Inspect the system for proper installation of EGR valve,
control switches and sensors. Inspect for proper connection of electrical
connectors and mechanical linkage.
Selective Catalytic Reduction (SCR) System
6.7L Diesel Engine
The SCR catalyst, Fig. 52, reduces NOx present in the
exhaust stream to nitrogen (N2) and water (H2O). At the inlet of SCR catalyst
is a port for reductant injector, followed by a louvered diffuser and a twist
mixer. DEF (Diesel Exhaust Fluid) is a solution of urea in deionized water.
When DEF is introduced into the system, it finely atomizes in louvered diffuser
and mixes evenly with exhaust gases in the twist mixer. During this time, heat
of exhaust gases causes urea to split into carbon dioxide (CO2) and ammonia
(NH3). As the ammonia and NOx pass over the SCR catalyst, a reduction reaction
takes place, and ammonia and NOx are converted to N2 and H2O. This reaction
takes place at up to 95% efficiency and allows the engine to run leaner and more
efficiently, since the high NOx levels that are produced under lean conditions
are eliminated.
Fig. 52 SCR catalyst. Ford 6.7L diesel engine
The SCR system should be inspected for damaged and missing
components. The instrument panel DEF indicator should be checked to ensure the
DEF tank is sufficiently filed. If the vehicle does not have DEF indicator,
check the tank fluid level.
Turbocharger
The turbocharger increases engine power by pumping
compressed air into the combustion chambers, allowing a greater quantity of
fuel to combust at the optimal air/fuel ratio. The turbine spins as exhaust gas
flows out of the engine and over turbine blades and turns the compressor wheel
at other ends of the turbine shaft, pumping more air into the intake system.
Regards,
Master Tech Lee
Contact me at
The positive crankcase ventilation system (PCV) is
yesterday’s technology with a new set of challenges. While most consider the
PCV system a simple and uneventful part of the emission control system, it can
have a detrimental effect on the overall engine performance. A component
failure can result in an array of problems, including rough idle, surging,
stalling, a sticking throttle plate, or excessive oil consumption.
The blowby vapors that end up in an engine’s crankcase
contain moisture as well as combustion concomitants and unburned fuel vapors.
The crankcase is sealed to prevent the escape of these gases into the
atmosphere, but the vapors must be removed to prevent oil contamination that
leads to sludge formation. The positive crankcase ventilation (PCV) system
siphons these vapors from the crankcase and routes them into the intake
manifold for the gases to burn off in the engine for a second time.
The main component in the PCV system is the PCV valve, which
is usually located in the valve cover. A hose connects the PCV valve to the
intake manifold. A second hose between the air cleaner and crankcase or other
valve cover (V6 or V8 applications) provides fresh air to help flush the vapors
out of the crankcase. Some engines have a separate air filter for the PCV
breather hose located inside the air cleaner.
The PCV valve is a spring-loaded valve with a specific
orifice size designed to restrict the amount of air that’s siphoned from the
crankcase into the intake manifold. This is necessary because air drawn through
the valve from the crankcase has a lean effect on the fuel mixture much the
same as a vacuum leak. So airflow is controlled through the valve within
certain limits. At idle, airflow is reduced because little blowby is produced.
When the engine is cruising and vacuum is high, airflow through the PCV valve
is at a maximum to purge the blowby vapors from the crankcase.
It’s important to note that PCV valves are sized for
specific engine applications. The wrong PCV valve for an application can allow
high-vacuum flow or too little air causing driveability problems.
Varnish deposits can clog the valve, so replacement for preventive
maintenance is recommended (every 50,000 miles usually).
Eventually, the PCV valve can be gummed up. Then it cannot move
enough air through the engine to keep it working efficiently. If the PCV valve
is sticking, you could have oil leaks, excess oil consumption, and a fouled
intake system. If you experience hesitation, surging, or an oil leak, it may be
a sign of PCV value problems.
PCV System Operation
PCV valve uses manifold vacuum to draw crankcase vapors back into the
intake manifold. Typically, blowby production is the greatest during high load
operations and very low blowby at idle on light load operations. Since the
characteristics of manifold vacuum do not match the flow, requirements needed
for proper crankcase ventilation, a PCV valve is used to regulate the blowby
flow back into the intake manifold.
• During idle and deceleration, blowby production is very
low, but intake manifold vacuum is very high. This causes the pintle inside the
PCV valve to retract fully against spring tension. The positioning of the pintale
provides a small vacuum passage and allows for low blowby flow to the
combustion chamber.
• During low load cruising, the pintle inside the PCV valve is positioned
somewhat in the center of its travel. This positioning allows a moderate
volume of blowby flow into the combustion chamber.
• During acceleration and heavy load operations, blowby production
is very high. The pintle extends out further from the restriction allowing the
maximum flow of blowby into the combustion chamber. During extremely high
engine loads, if the blowby volume exceeds the ability of the PCV valve to draw
in the vapors, the excess blowby flows through the breather hose to the air
cleaner housing where it can enter the combustion chamber.
• When the engine is off or it backfires, spring tension
closes the valve completely preventing the release of blowby into the intake
manifold. The valve closes during a backfire to prevent the flame from
traveling into the crankcase where it could ignite the enclosed fuel vapors.
PCV System Effects on Emissions and Driveability Because PCV
operation is factored into the proper operation of the feedback control system,
problems with the PCV system may disrupt the normal air/fuel ratio balance. A
clogged PCV valve will prevent the regular flow of crankcase vapors into the
engine and can result in a richer than normal air/fuel mixture. A plugged
crankcase breather hose may cause the engine to consume oil because of the
increased level of crankcase vacuum.
In addition, depending on the location of the fresh air breather hose, a
nonfunctional valve or restricted vacuum hose can cause oil contamination in the
air cleaner housing or throttle bore coking.
Always suspect and check the PCV system if you find traces of oil in the air intake system.
If the crankcase becomes diluted with fuel, carbon monoxide
(CO) levels will likely increase because the PCV system will meter extra fuel
vapor into the intake system. Always replace fuel diluted engine oil and
identify and resolve the problem causing the fuel contaminated.
Although there are no mandatory maintenance intervals for
the PCV system, periodically check the system for a plugged or gummed PCV valve
and damaged hoses. Replace suspect components as necessary. Since PCV flow
rates differ between vehicle models, it is important to use the correct
replacement PCV valve to ensure proper operation. The installation of an incorrect
valve may cause an engine to stall, rough idle and other driveability
complaints. Thus, never install universal type PCV valves.
PCV System Functional Tests
The following RPM Drop Test may be used as a basic quick
check to confirm that the PCV system is functioning:
Start the engine and allow it to reach operating
temperature.
• Allow the engine to stabilize at idle
• Pinch or block the hose between the PCV valve and vacuum
source
• Typically, engine rpm should drop around 50 rpm if engine
rpm does not change, check the PCV valve and system hoses for blockage.
• Replace components as necessary and then retest the system.
PCV valve diagrams
GM
1 - Valve Cover 2 - EVAP Canister Purge Solenoid Valve 3 - To EVAP Canister 4 - Throttle Body 5 - Intake Manifold 6 - Positive Crankcase Ventilation (PCV) Valve
Ford
Need Help with your PCV valve, or Next Repair? Contact Us Now!
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Regards,
Master Tech Lee
TSB 10-19-4
10/11/10
CLUTCH STAYOUT AT HIGH RPM – BUILT ON OR
BEFORE 4/25/2010
FORD:
2011 Mustang
ISSUE
Some 2011 Mustangs built on or before 4/25/2010: with a manual transmission and low mileage, typically 10,000 miles or less (16.093 Km), may exhibit a clutch pedal Stayout condition at very high engine RPM. This condition will generate a concern of the clutch pedal remaining on the floor dining high engine RPM shifts. When engine RPM drops, clutch pedal operation returns to normal, but the re-engagement may be abrupt.
ACTION
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
The clutch pedal Stayout is a condition where at high engine RPM, centrifugal forces or the clutch system can reduce the force with which the clutch diaphragm fingers push against the release beating. This can result in the Clutch pedal staving on the floor until engine RPM decreases and the diaphragm return force increases.
Parts Block
1. Replace the Brake Pedal and Bracket assembly. Refer to Workshop Manual, Section
206-06.
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty
Coverage
OPERATION DESCRIPTION TIME
101904A 2011 Mustang MT82 0.8 Hr.
Transmission: Replace the Brake Pedal and Bracket Assembly
To all my Fans out there in cyber space, It has come to where I am going into a treatment program for cancer hope to be back home July 15, 2012. And after a couple of weeks, from 15 of July, I will resume my posts and reactivate www.fixcar1.com and www.autohelprepair.com.
Thank you ALL for the wishing well e-mails.
Love you all,
Master Tech Lee
Cooling systems can be your best friend when operating efficiently. Cooling system repairs. . . Your worst enemy if you don’t understand how your cooling system works.
Your cooling system performs a critical function. Simply put it maintains proper engine temperature by circulating coolant through the engine to pick up heat and passing it through a radiator to cool it with air. The coolant passes through a thermostat valve to control flow and possibly over a temperature sensor which controls external air cooling fans.
Cooling systems consist of three main parts:
Cooling System Part #1: Your cooling systems pumping function is handled by its water pump, which keeps the coolant mixture moving.
The main water pump is gear or belt-driven, but in many cars, a secondary electric water pump is used for improved flow and cooling.
Critical to the pumps operation is the drive belt that turns it on most newer cars this is the engine’s timing belt. On older cars, the pump and belt are external and run off the main crankshaft pulley with a V or flat belt.
Maintenance of the cooling system pumping is limited to scheduled coolant replacement and drive-belt replacement and tension adjustment (external type). Timing-belt-driven pumps should always be replaced at the same time as the timing belt and tensioner.
Cooling System Part#2: Piping
Your cooling systems piping consists of all hoses, any control valves, the heater core, the radiator and the expansion tank. Because of the materials used and the constant contact with coolant all parts in this system deteriorate more from time than use.
Maintenance of cooling system piping consists of scheduled coolant replacement of all hoses regularly. Replace leaking parts, such as water pump , , , intake manifold and thermostat housing gaskets.
All hoses should be checked at least twice a year for abrasions, cracks, flexibility and evidence of leakage. Whenever the coolant is drained for replacement or during engine repairs, any suspect hoses should be replaced. All hoses should be replaced at least every few years.
Radiators, expansion tanks, heater cores and control valves are normally only replaced due to leakage or plugging. The condition of these parts should be assessed by a professional since proper functioning is critical to many other systems within your car.
Cooling System Part#3: Temperature Control
Your cooling system’s temperature controls include all coolant temperature sensors, thermostat radiator or expansion tank cap,cooling fan(s) and fan clutch (if equipped). These cooling system parts function primarily independent of the engine but control the engine either through cooling or by sending control signals to your car’s electronic systems.
The thermostat is a spring-loaded valve that opens and closes based on the temperature of the coolant flowing through it. A high-temperature reading followed by a drop to normal temperature (or a continuously low temperature) is a common first sign of a sticking thermostat. However; many other conditions may cause these symptoms, so you need to know how to eliminate each possibility.
The radiator or expansion tank cap is also a spring-loaded valve reading to system pressure. It serves to maintain a proper system coolant level at predetermined pressures. It must always be replaced with an exact replacement cap with the same pressure setting. Never use other caps except for short-term emergencies!
A belt-driven fan blade for pulling air through the radiator is usually on the water pump pulley and should have a fan clutch to control it. The fan clutch allows the fan to turn with the belt at low engine speed and free-wheel at higher speeds. A bad fan clutch either doesn’t allow the fan to spin at a base speed (overheating in traffic) or does allow it to free-wheel at high speed (potential overheating on highway or reduced gas mileage).
An electric fan can be either by itself (usually front-wheel drive) or auxiliary (used with a mechanical fan). Both types are controlled via a temperature sensor – in the radiator or upper radiator hose or on the thermostat or water pump housing. This sensor is usually an on and off type switch with a fixed temperature setting. (Some vehicles may have 2-3 settings for multi-speed fans.) This sensor is commonly called an auxiliary fan switch.
Other common temperature sensors are: 1) gauge sender (variable output): 2) warning light sender (on/off type): 3) lambda and/or fuel injection sensor(s) (variable to control fuel injection settings); 4) thermo-time switch (cold start valve control). Your car may have other sensors as well.
Temperature control is critical to both performance and emission control. Unfortunately, this system is the most difficult to troubleshoot without the proper equipment and diagrams. It’s even more unmanageable with computers that adjust timing, idle speed, and vacuum and fuel delivery automatically to make up for potentially faulty temperature sensor signals.
Maintenance of your cooling system sensors is virtually impossible, since there’s nothing really to maintain. Keeping them clean both internally (coolant replacement) and externally (engine cleaning) is the best way to ensure trouble-free driving. Checking and replacing all parts at the factory-recommended time or mileage limits helps as well.
A Few Important Things to Remember
Heed these cooling system maintenance tips and you’re well on your way to ensuring your cooling system won’t let you down:
Tip #1: Keep your engine and engine compartment as well as your radiator fins and grill, as clear as possible. A clean engine runs much cooler – plus it is easier to work on.
Tip #2: Replace coolant at or before the factory recommended intervals with the proper type, mixture and volume of coolant always allow the coolant system to rid itself of air before installing the radiator cap.
Tip #3: Replace all cooling system hoses – upper and lower radiator hoses, bypass hoses, heater hoses, manifold coolant hoses and any other hoses on your vehicle-whenever you even suspect there may be a problem. All hoses should be replaced at least every two years.
Tip #4: Replace the thermostat with the original temperature setting equivalent the electronics in your vehicle may use that setting for other controls. Do not substitute under any circumstances.
Tip #5: Replace the radiator/expansion tank cap with the original pressure setting and 0E-type equivalent. Some aftermarket substitutions do not seal and hold pressure properly on foreign-manufactured cars. Again, don’t substitute under any circumstances.
Tip #6: Adjust or replace the water pump serpentine, or V, belt (external) at recommended intervals or more frequently, if required. Check belts whenever you’re working on any coolant system components.
Tip #7: Replace your water pump with a OEM/DES pump at the first signs of trouble or when your timing belt and tensioner are replaced. Watch for signs of overheating – you don’t want to break down in the hot sun when your water pump fails.
Tip #8: Replace the fan clutch and/or fan blade as needed (if applicable). Your car’s temperature gauge is often your best guide as to when your fan clutch needs attention.
Tip #9: Replace temperature sensors as required by diagnosis. Leave troubleshooting of your sensors to www.fixcar1.com who can help you step by step, and with diagrams.
Tip #10: Keep your entire vehicle well maintained because of the effect timing, idle speed. Exhaust and other systems have on your engine’s temperature. Your car’s cooling system is designed to function with all other systems operating properly. It cannot make up for a poorly operating or overheating engine condition.
Your Cooling System Parts Shopping List
Here’s a list of cooling system repair parts you should consider when repairing your car’s cooling system:- Coolant — Water Pump –Water Pump Drive Belt (timing, serpentine, or V-belt. )– Hoses (upper & lower radiator, bypass, heater, manifold coolant, etc.) — Radiator– Expansion Tank– Heater Core — Control Valves — Temperature Sensors, as applicable*- Radiator Cap and/or Expansion Tank Cap — Fan Clutch - Auxiliary fan switch, gauge sender, warning light sender, lambda, fuel injection, thermo-time switch, etc.
Regards,
Master Tech Lee
Need help with your auto just ask me! E-mail: fixmycar@fixcar1.com
Web Site: www.fixcar1.com
I have seen on many car forums, auto groups, and crowed sourced web sites, which the expert tells the customer to disconnect the battery to clear the problem. Watch out!! Some cars will be damaged and/or in need of reprogramming.
Let us take, for example, a 2000 BMW 325I Sedan (E46). The MK3 Navigation computer powers down in approximately 60 seconds after the ignition has been turned OFF (red LED on the computer goes OFF). If the power supply to the MK3 unit is interrupted (by removing disconnecting the computer from the vehicle, or by disconnecting the vehicle’s battery) in the time period of 55 to 57 seconds after the ignition has been turned OFF, the power-down procedure (“erase and save data in Non Volatile RAM”) can be corrupted. This will result in a total failure of the MK3 computer (red LED off, CD eject function inoperative, board monitor screen permanently blank, and no sound from the audio system). In such a case, the navigation computer has to be replaced.
CORRECTION:On vehicles with MK3 navigation system, prior to disconnecting the battery or removing (disconnecting) the Nav computer, make sure the MK3 Navigator’s computer is in the power-down mode (red LED on the unit is OFF) by using the magnetic pen,
WARRANTY INFORMATION: Damaged MK3 Nay computers caused by not following the required power-down procedure are not considered defective and are not warranty covered.
Automotive Tip: Above is one example in taking the time to follow all procedures before disconnecting your automotive
battery. Radio codes, and all the settings will be lost due to battery disconnect. Some automotive makes and models you can use a Battery Saver Tool. Plugs right in the Cigarette lighter to help you keep all engine codes and feature settings intact, so you will not have to reprogram the radio and all its’ settings. Including covenant settings, such as memory power seats, clock, radio stations,
and, etc.
Domestic and Import car, truck, and van owners:
Please consult your vehicle Owner’s Manual before you disconnect your car’s battery to see if your car has a disconnect procedure.
Ask a Technician Now to see if your car’s battery can be safely disconnected. Please go to our website page at http://www.fixcar1.com
Regards,
Master Tech Lee
REMOVAL PROCEDURE FOR SEIZED EXHAUST O2 SENSOR
SERVICE INFORMATION
If an exhaust sensor is seized in the exhaust manifold catalyst front tube perform the
procedure described in this bulletin to remove the sensor and prevent unnecessary
replacement of the exhaust manifold catalyst front tube.
In most cases this procedure is successful. This is because the threads of the exhaust
sensors are made of a softer material than the part they thread into on the exhaust
manifold catalyst front tube.
NOTE:
The replacement of exhaust manifolds catalysts front tubes for stripped exhaust
sensor threads may not be considered a warrantable expense.
This procedure can be performed by two methods:
Method #1. If the Sensor Can Be Easily Accessed
The procedure can be performed on the vehicle.
• The exhaust manifold catalyst front tube will not have to be removed.
Method #2. If the Sensor Cannot Be Easily Accessed
The exhaust manifold catalyst front tube must be removed from the vehicle.
The procedure will be performed with the part clamped in a vice.
Method # 2 is described in this blog. Method # 1 is the same as Method # 2 except that it is performed on the vehicle.
SERVICE PROCEDURE
Rust Penetrate
Recommended rust penetrate to be used in this procedure:
WD—40 is available from various local sources.
Removal Tool
When removing a seized exhaust sensor with a specialty socket (which contains a 
slit to accommodate the wiring harness) it may spread open and strip the sensor.
Before this occurs it is recommended to cut the wiring harness from the sensor and
use a box end wrench or 6-point deep well socket.
1. Clamp the exhaust manifold catalyst front tube in a vice.
2. Spray the sensor with the rust penetrate for 2 to 3 seconds.
It is important that the spray is directed at the base of the sensor to ensure it
penetrates into the threads.
3. Loosen the sensor approximately 10 degrees.
4. Spray with rust penetrate again for 2 to 3 seconds.
5. Tighten the sensor 10 degrees then loosen the sensor 10 degrees.
: Repeat this motion several times until the sensor begins to turn more easily.
6. Continue the tightening loosening motion while gradually unscrewing the sensor.
Stop when the sensor will not unscrew any further.
Spray with rust penetrate again for 2 to 3 seconds.
Repeat steps 6 and 7 until the sensor is removed.
Use compressed air to remove any metal debris from inside the boss threads.
CAUTION:
DO NOT perform this step if the procedure is being done on the vehicle (3.Method # 1). Doing so may cause metal debris to enter the engine cylinders.
10. If metal debris remains trapped in the boss threads use a spiral nylon brush to remove them.
11. Spray the boss threads with rust penetrate for 2 to 3 seconds.
12. Run a thread chaser through the boss to clean the threads.
“Use Kent Moore part number 3-43897-18 or 343 897-12.
13. Use compressed air to remove any remaining debris.
CAUTION:
DO NOT perform this step if the procedure is being done on the vehicle (Method
# 1). Doing so may cause metal debris to enter the engine cylinders.
14. If metal debris remains trapped in the boss threads use a spiral nylon brush to remove it.
15. Tilt the manifold catalyst front tube so that the metal debris falls out of the part.
16. Apply compressed air through the boss to blow out any remaining debris.
CAUTION:
DO NOT perform this step if the procedure is being done on the vehicle (Method #1)
Doing so may cause metal debris to enter the engine cylinders.
17. Install the new sensor.
Visit www.fixcar1.com for all your automotive repair needs today.
Thank you for your visit and business!!
Regards,
SERVICE INFORMATION
Any vehicle may have a low voltage display (if equipped with gauges), lights that dim at stop lights, slow cranking, no start, low generator output at idle or dim lights at idle when electrical loads are heavy at idle or under slow driving or infrequent usage conditions. These characteristics may be more noticeable with customer added electrical accessories, or with a discharged battery. These are normal operating characteristics of a vehicle electrical system and no repairs should be attempted unless a proven fault has been diagnosed.
During normal driving conditions, when engine speed is above 1000 RPM, the generator is designed to do two things:
- Supply the current necessary to operate the vehicle’s originally equipped electrical devices (Loads).
- Recharge maintain the battery’s state of charge.
The following factors may affect generator and battery performance:
- Non-usage of the vehicle for extended periods of time the vehicle’s computers, clocks and the like will cause the battery state of charge to drop (For example; 30 days in a parking lot and the vehicle may not start because of a dead battery or a vehicle, which is driven only a short distance once a week may end up with a discharged battery to the point where the vehicle may not start). This would be considered abnormal usage of the vehicle and the normally expected result for the vehicle battery, generator and electrical systems.
- At idle, vehicle electrical loads may exceed the low-speed current (amperage) output of the generator and when this happens the shortfall comes from the battery. This will result in a drop in the electrical system voltage as the battery delivers the additional electrical current to meet the demand. This is equivalent to the brown outs experienced by homes and businesses when the electrical demand is more than the supply. See Fig. 1.
Fig. 1: View of Typical Generator Performance Courtesy of GENERAL MOTORS CORP.
- Extended periods of engine idling, with high electrical loads. may result in a discharged battery. Attempting to recharge a battery by letting the engine run at idle may not be beneficial unless all electrical loads are turned “OFF”.
- Increased internal generator temperatures from extended idling can also contribute to lower electrical system voltage. As the generator’s internal temperature rises, the generator’s output capability is reduced due to increased electrical resistance.
Examples of Electrical Loads
| System | Amperage Load |
| Rear Window | 25 |
| Electric Air Pump | 25 |
| Heated Seats | 5 Amps per Seat |
| HeadLamps (High) | 20 |
| Blower Motor (High) | 20 |
| HeadLamps (Low) | 15 |
| Brake Lights | 6 |
| Windshield Wipers | 6 |
| Ignition | 6 |
Depending on the vehicle application, generator current (amperage) output at engine idle speeds of 600-700 RPM can be as low as 35 percent of the full rated output. With enough electrical loads “ON”, it is easy to exceed the generator current (amperage) output when the engine is at an idle of 600-700 RPM. This is a normal condition. The battery supplements for short periods of time. Items that affect the vehicles electrical system current and voltage at idle are the number of electrical loads being used, including add-on accessories, and extended idle times. When the vehicle speed is above approximately 24 km/h (15 mph), the engine “generator RPM is high enough and the generator current (amperage) output is sufficient to supply the current (amperage) requirements of the vehicle as originally equipped and recharge the battery.
Dimming lights at idle may be considered normal for two reasons:
1. As the engine’ generator speed changes, so will the current (amperage) output of the generator As a vehicle slows, engine’ generator RPM slows and the current (amperage) output of the generator may not be sufficient to supply the loads, the vehicle system voltage will drop and the lights will dim. Dimming of the lights is an indication that current is being pulled from the battery. If the battery is in a low state-of-charge (discharged condition), the driver will notice a more pronounced dimming than a vehicle with a fully charged battery.
2. When high current loads (blower, rear defogger, headlamps. cooling fan, heated seats: power seats, electric “AIR” pump, or power windows) are operating or cycled “ON”, the generator’s voltage regulator can delay the rise in output. This effect, usually at lower engine speeds, can take up to ten seconds to ramp up the generator output. This is done to avoid loading the engine severely. To increase current (amperage) output, the generator consumes additional torque. The engine computer (ECM/PCM) will ramp up engine/generator speed in small steps so engine speed variations are not noticeable to the driver.
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