egr system
Thread Starter
Joined: Dec 2005
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egr system
i replaced my egr valve yesterday because i kept getting a code 32 on my 95 ram 1500 5.9. my question is when i pulled the old one off, i noticed that there was water in the old valve and solenoid, that was what caused my cold weather idling problem, i am assuming it froze up in there. how does water get in the vacuum system.
Champion
Joined: Aug 2005
Posts: 3,313
Likes: 8
RE: egr system
Exhaust gas naturally has steam in it.
In cold weather this steam condenses to liquid water,
and I am sure you have seen water dripping out of the
exhaust pipe on cold mornings.
The EGR system diverts part of the exhaust gas
and just like the tailpipe some of the steam can
condense to liquid water inside the EGR system.
An even greater problem in EGR system is that soot
from the exhaust gas builds up as carbon deposits in
the passages of the EGR system.
More info from an old posts:
----
===
>The 1995 Factory Service Manual warns that the EGR system commonly clogs up
with carbon deposits, so after 150,000 miles that seems like it would be a
major probability.
The manual also tells dealer tech to 'just replace clogged tubes & parts -
don't try to clean out carbon.' On the cheap, you might be able to clean
clogged tubes with a piece of wire chucked up in a hand drill. Oven
cleaner foam spray might help some.
I've never tried it, but I suspect soaking parts in Chevron's Techron fuel
gasoline additive/cleaner might work too.
The Ram EGR system starts re-circulating exhaust gas when the 12 volt
electrical power to it is TURNED OFF - so if someone has disabled the
system by pulling a wire, that can also cause the problem. The computer
does this turning off by opening the ground wire connection from the EGR
solenoid.
The actual EGR valve is moved by a vacuum cylinder and needs some
'feedback' of back-pressure from the exhaust pipes - so you also have to
check the rubber vacuum lines & diaphrams, and fake some backpressure.
The manual says you test the EGR system by:
(1) disconnecting the ground wire
(2) raising the rpm above idle to +2000 rpm
(3) having a friend block half to two thirds of the tailpipe's end to
simulate some back pressure.
If the system is working, the EGR will come on after steps 1-3 and the
engine will begin running rough or even stall out. You can also look for an
'indicator stem' to rise on the EGR valve.
The computer calls for EGR when:
(a) The engine rpms are in the mid range of 2000-3500
(b) The throttle is only partly open.
At low rpm with part throttle - or wide open throttle - the computer will
not be asking for EGR, and so won't be able to detect and trigger a trouble
code. You could easily make 'easy driving' trips that avoid the mid range
rpms and so not get a light.
Shouldn't be all that expensive, especially if all you have to do is open
up some carbon clogged passages, connect a wire, or replace a vacuum hose.
If carbon has clogged the EGR system, you might want to spend $25 and run
2-3 bottles of Chevron Techron additive through your next 60 gallons of
gasoline.
You might even want to run the 2-3 tank fulls of Techron treated gas before
you take the EGR system apart. It couldn't hurt, and might clean the EGR
passages some.
-Hank
Sat Jul 24 16:41:33 1999
Subject: Trying to clean EGR valve with Techron/throttle body spray
In talking with a tech at my Dodge dealer last week, I mentioned that my
ScanTool was showing that the Intake Air Temperature was running 125-145
degrees F while driving around and sometimes as high as 170 at idle. The
tech told me that the driving around temps were normal - that it was
because I had EGR on my 1995 5.9L V8 - the hot exhaust gases were mixing
with and warming the cool air coming into the intake manifold from the
'cold air intake'.
(Newer model post-1996 Rams don't have EGR anymore)
But the tech also said that the EGR should have been shut off when the
truck was at idle - and that the high temps at idle were probably a sign
that I had some leakage through the EGR valve - probably due to carbon
buildup at the seat of the vacuum controlled EGR valve. He asked me how
many miles I had on the truck (68,000) and then he said most of the Ram's
EGR valves wouldn't completely close at higher mileage. Another sign of
this lack of complete shut-off is a rougher idle.
I asked if there was anything I could do about it and he said 'The book
says not to try to clean them - just replace them.' Cost at the dealer is
about $200 for parts and 4 hours labor, which would be another couple
hundred.
That is what my '95 factory service manual says - but I decided to try some
cleaning this morning. The manual shows that the EGR Valve and its sister
EGR Vacuum Control Valve are connected by two rubber hoses - the upper
rubber hose is the vacuum line and the lower rubber hose is the 'exhaust
backpressure feedback' line.
The manual says that the test to see if the EGR valve is leaking when it
should be shut off is to disconnect the lower rubber hose from the EGR
Vacuum Control Valve side - the exhaust backpressure hose - and try to blow
50 psi compressed air into the EGR valve through the end of the
backpressure hose with the engine off. If you hear air rushing into the
intake manifold - the EGR valve seat is leaking.
I have been impressed with Chevron's Techron fuel system cleaner. It seems
to make my engine run smoother after adding two bottles to 26 gallons and
its ads claim that it cleans carbon deposits out of valves and cylinder
heads.
I decided to try to check my EGR valve and then try to flush some Techron
through it if it was leaking.
The EGR valve and the EGR Control valve are hidden behind the passenger
side valve bank with lotsa ignition wires, harnesses and vacuum lines
overtop them. You have to work by feel as you can't hardly see anything -
but with a stone cold engine finding the lower rubber hose and pulling it
off was easy - there are no clamps. The short 3 inch long black rubber
hose looked ok outside - but inside I could see some gunk deposits that
came out pretty easy.
I connected a six foot long hose to the EGR valve lower nipple and could
blow air through it into the intake manifold. I then elevated my end of
the hose and poured about 2 ounces of Techron down it. I pushed my end of
the hose into one of the holes in the Ram's grill - to keep it elevated so
the Techron would run downhill - and let everything soak for 30 minutes.
After the 30 minute soak I started the engine up. The engine took a few
more turnovers than usual but started up without too much trouble. The
hose now had exhaust gas coming out the end with a gurgling sound to it.
There was not much pressure, you could easily stop it with the end of your
thumb.
I decided to add some more Techron. I did this by pinching the hose shut
about two feet down from the end - pouring in enough Techron to fill the
hose for 4-5 ihches - then putting my thumb over the hose end and letting
go of the lower pinch point. I found that the Techron would flow down the
hose and build up enough pressure to shut off the flow of exhaust gas for
awhile. When the exhaust gas started coming out the end of the hose again
- I would add some more Techron.
I did this for about 15 minutes. The idle did seem to get a bit smoother.
I also had about half a can of Throttle Body spray and decided to spray
some of this down the hose. When I did, it didn't seem to affect the idle
at all, so I was hoping that the EGR valve was seated better and no longer
leaking. I shut off the engine and then used up the rest of the cleaner
spraying the throttle bores and the IAC port.
I restarted the truck and took a test drive with the ScanTool hooked up.
The IAC temperature did seem to be lower - it stayed between 130-150 during
the driving and would not go up as much as before when the truck was
stopped and idling.
I may buy a piece of rubber hose and immerse it in a glass jar filled with
Techron. If the hose doesn't show any deterioration after a 12 hour soak,
I may try this flush again and let the Techron soak the EGR valve
overnight.
I have also been impressed with how well Castrol Superclean can clean up
things and break down deposits. I have pondered trying an EGR valve soak
with Superclean - but I am a little worried about what kind of deposits the
Superclean would leave inside the engine when it gets sucked through the
EGR passageways into the intake manifold.
In cold weather this steam condenses to liquid water,
and I am sure you have seen water dripping out of the
exhaust pipe on cold mornings.
The EGR system diverts part of the exhaust gas
and just like the tailpipe some of the steam can
condense to liquid water inside the EGR system.
An even greater problem in EGR system is that soot
from the exhaust gas builds up as carbon deposits in
the passages of the EGR system.
More info from an old posts:
----
===
>The 1995 Factory Service Manual warns that the EGR system commonly clogs up
with carbon deposits, so after 150,000 miles that seems like it would be a
major probability.
The manual also tells dealer tech to 'just replace clogged tubes & parts -
don't try to clean out carbon.' On the cheap, you might be able to clean
clogged tubes with a piece of wire chucked up in a hand drill. Oven
cleaner foam spray might help some.
I've never tried it, but I suspect soaking parts in Chevron's Techron fuel
gasoline additive/cleaner might work too.
The Ram EGR system starts re-circulating exhaust gas when the 12 volt
electrical power to it is TURNED OFF - so if someone has disabled the
system by pulling a wire, that can also cause the problem. The computer
does this turning off by opening the ground wire connection from the EGR
solenoid.
The actual EGR valve is moved by a vacuum cylinder and needs some
'feedback' of back-pressure from the exhaust pipes - so you also have to
check the rubber vacuum lines & diaphrams, and fake some backpressure.
The manual says you test the EGR system by:
(1) disconnecting the ground wire
(2) raising the rpm above idle to +2000 rpm
(3) having a friend block half to two thirds of the tailpipe's end to
simulate some back pressure.
If the system is working, the EGR will come on after steps 1-3 and the
engine will begin running rough or even stall out. You can also look for an
'indicator stem' to rise on the EGR valve.
The computer calls for EGR when:
(a) The engine rpms are in the mid range of 2000-3500
(b) The throttle is only partly open.
At low rpm with part throttle - or wide open throttle - the computer will
not be asking for EGR, and so won't be able to detect and trigger a trouble
code. You could easily make 'easy driving' trips that avoid the mid range
rpms and so not get a light.
Shouldn't be all that expensive, especially if all you have to do is open
up some carbon clogged passages, connect a wire, or replace a vacuum hose.
If carbon has clogged the EGR system, you might want to spend $25 and run
2-3 bottles of Chevron Techron additive through your next 60 gallons of
gasoline.
You might even want to run the 2-3 tank fulls of Techron treated gas before
you take the EGR system apart. It couldn't hurt, and might clean the EGR
passages some.
-Hank
Sat Jul 24 16:41:33 1999
Subject: Trying to clean EGR valve with Techron/throttle body spray
In talking with a tech at my Dodge dealer last week, I mentioned that my
ScanTool was showing that the Intake Air Temperature was running 125-145
degrees F while driving around and sometimes as high as 170 at idle. The
tech told me that the driving around temps were normal - that it was
because I had EGR on my 1995 5.9L V8 - the hot exhaust gases were mixing
with and warming the cool air coming into the intake manifold from the
'cold air intake'.
(Newer model post-1996 Rams don't have EGR anymore)
But the tech also said that the EGR should have been shut off when the
truck was at idle - and that the high temps at idle were probably a sign
that I had some leakage through the EGR valve - probably due to carbon
buildup at the seat of the vacuum controlled EGR valve. He asked me how
many miles I had on the truck (68,000) and then he said most of the Ram's
EGR valves wouldn't completely close at higher mileage. Another sign of
this lack of complete shut-off is a rougher idle.
I asked if there was anything I could do about it and he said 'The book
says not to try to clean them - just replace them.' Cost at the dealer is
about $200 for parts and 4 hours labor, which would be another couple
hundred.
That is what my '95 factory service manual says - but I decided to try some
cleaning this morning. The manual shows that the EGR Valve and its sister
EGR Vacuum Control Valve are connected by two rubber hoses - the upper
rubber hose is the vacuum line and the lower rubber hose is the 'exhaust
backpressure feedback' line.
The manual says that the test to see if the EGR valve is leaking when it
should be shut off is to disconnect the lower rubber hose from the EGR
Vacuum Control Valve side - the exhaust backpressure hose - and try to blow
50 psi compressed air into the EGR valve through the end of the
backpressure hose with the engine off. If you hear air rushing into the
intake manifold - the EGR valve seat is leaking.
I have been impressed with Chevron's Techron fuel system cleaner. It seems
to make my engine run smoother after adding two bottles to 26 gallons and
its ads claim that it cleans carbon deposits out of valves and cylinder
heads.
I decided to try to check my EGR valve and then try to flush some Techron
through it if it was leaking.
The EGR valve and the EGR Control valve are hidden behind the passenger
side valve bank with lotsa ignition wires, harnesses and vacuum lines
overtop them. You have to work by feel as you can't hardly see anything -
but with a stone cold engine finding the lower rubber hose and pulling it
off was easy - there are no clamps. The short 3 inch long black rubber
hose looked ok outside - but inside I could see some gunk deposits that
came out pretty easy.
I connected a six foot long hose to the EGR valve lower nipple and could
blow air through it into the intake manifold. I then elevated my end of
the hose and poured about 2 ounces of Techron down it. I pushed my end of
the hose into one of the holes in the Ram's grill - to keep it elevated so
the Techron would run downhill - and let everything soak for 30 minutes.
After the 30 minute soak I started the engine up. The engine took a few
more turnovers than usual but started up without too much trouble. The
hose now had exhaust gas coming out the end with a gurgling sound to it.
There was not much pressure, you could easily stop it with the end of your
thumb.
I decided to add some more Techron. I did this by pinching the hose shut
about two feet down from the end - pouring in enough Techron to fill the
hose for 4-5 ihches - then putting my thumb over the hose end and letting
go of the lower pinch point. I found that the Techron would flow down the
hose and build up enough pressure to shut off the flow of exhaust gas for
awhile. When the exhaust gas started coming out the end of the hose again
- I would add some more Techron.
I did this for about 15 minutes. The idle did seem to get a bit smoother.
I also had about half a can of Throttle Body spray and decided to spray
some of this down the hose. When I did, it didn't seem to affect the idle
at all, so I was hoping that the EGR valve was seated better and no longer
leaking. I shut off the engine and then used up the rest of the cleaner
spraying the throttle bores and the IAC port.
I restarted the truck and took a test drive with the ScanTool hooked up.
The IAC temperature did seem to be lower - it stayed between 130-150 during
the driving and would not go up as much as before when the truck was
stopped and idling.
I may buy a piece of rubber hose and immerse it in a glass jar filled with
Techron. If the hose doesn't show any deterioration after a 12 hour soak,
I may try this flush again and let the Techron soak the EGR valve
overnight.
I have also been impressed with how well Castrol Superclean can clean up
things and break down deposits. I have pondered trying an EGR valve soak
with Superclean - but I am a little worried about what kind of deposits the
Superclean would leave inside the engine when it gets sucked through the
EGR passageways into the intake manifold.
Joined: Feb 2006
Posts: 20
Likes: 0
RE: egr system
hi,
most common scenario is restricted cat.converter.with exh restriction ,very hot exh flws through vlv and melting modulator on extreme cases, and also condensating ,would cause an intermittent stall at that first stop sign, and run great for the rest of the day, trapped water froze the valve open until it warms up.
greasemonkey
most common scenario is restricted cat.converter.with exh restriction ,very hot exh flws through vlv and melting modulator on extreme cases, and also condensating ,would cause an intermittent stall at that first stop sign, and run great for the rest of the day, trapped water froze the valve open until it warms up.
greasemonkey
