1999 GMC Chevy Suburban - EGR Issues

[dan]

I just replaced the EGR valve in my 99 Suburban (K1500 - 5.7L) …
again. I am wondering if there is something else that I should look
at. I would imagine that the new valve could fail as well (because
there may be some other problem)

I was getting a P0404 code about 6 months ago (I have a code reader).
The car had typical EGR issues (rough idle, surging …) I removed the
old factory original EGR valve and cleaned the mounting area up (it
was not particularly dirty) and replaced the EGR valve and gasket with
a unit from Pep Boys. The brand was BWD I believe. The truck
immediately ran fine and the check engine light stayed out for the
last six months. The 99 Suburban uses one of those linear/electronic
EGR valves, and they are expensive (~$120 or more depending on which
part you buy).

A few days ago the truck turns on the check engine light again. It's
that good old P0404 code (EGR Performance). Indeed the truck is again
exhibiting EGR like issues (surging, particularly at lower RPMs). The
idle was not rough, but the truck was surging just like when the other
valve was bad.

I bite the bullet and buy a new EGR valve (since it did seem like the
EGR was bad). I removed the 6 month old EGR valve and cleaned the
mounting area up (it was still clean) and replaced the EGR valve and
gasket with an identical unit from Pep Boys. The truck immediately
runs fine again. I don't know whether the check engine light will
stay out … but the truck does run perfectly fine again.

I will search for my receipt for the old valve since I believe it is
still under warranty. However, I wonder if there could be something
else that could be causing the EGR valves to fail. Any thoughts,
cause this could be expensive if I have to put in a new EGR every 6
months.

Thanks,
Dan

[Steve W.]

>
> I just replaced the EGR valve in my 99 Suburban (K1500 - 5.7L) …
> again. I am wondering if there is something else that I should look
> at. I would imagine that the new valve could fail as well (because
> there may be some other problem)
>
> I was getting a P0404 code about 6 months ago (I have a code reader).
> The car had typical EGR issues (rough idle, surging …) I removed the
> old factory original EGR valve and cleaned the mounting area up (it
> was not particularly dirty) and replaced the EGR valve and gasket with
> a unit from Pep Boys. The brand was BWD I believe. The truck
> immediately ran fine and the check engine light stayed out for the
> last six months. The 99 Suburban uses one of those linear/electronic
> EGR valves, and they are expensive (~$120 or more depending on which
> part you buy).
>
> A few days ago the truck turns on the check engine light again. It's
> that good old P0404 code (EGR Performance). Indeed the truck is again
> exhibiting EGR like issues (surging, particularly at lower RPMs). The
> idle was not rough, but the truck was surging just like when the other
> valve was bad.
>
> I bite the bullet and buy a new EGR valve (since it did seem like the
> EGR was bad). I removed the 6 month old EGR valve and cleaned the
> mounting area up (it was still clean) and replaced the EGR valve and
> gasket with an identical unit from Pep Boys. The truck immediately
> runs fine again. I don't know whether the check engine light will
> stay out … but the truck does run perfectly fine again.
>
> I will search for my receipt for the old valve since I believe it is
> still under warranty. However, I wonder if there could be something
> else that could be causing the EGR valves to fail. Any thoughts,
> cause this could be expensive if I have to put in a new EGR every 6
> months.
>
> Thanks,
> Dan

You need to clean out the passages in the intake. They are likely full
of carbon and crud, which is what is causing the problem. Pull the valve
off and use some stiff wire or cable to run down the passages. Once you
have it cleared out go get a can of SeaFoam or GM top cylinder cleaner
and run it through the engine. That will dissolve more carbon and allow
it to blow out of the engine through the exhaust. The easy way to use
either one is to pull the brake booster line off and allow the engine to
draw the cleaner in. Let it draw in about half the can or until the
engine stalls. Then shut off the key and let it set for 20 minutes or
so. Dump the rest in the gas tank. Now start the engine and take it for
a drive to burn off the cleaner and blow the crud out. It will generate
a LOT of smoke and spray soot and carbon out the tailpipe. DON'T USE IT
IN A GARAGE or enclosed area. Make sure the tailpipe isn't aimed at
anything that you don't want covered with carbon and crud.

[mac davis]

>You need to clean out the passages in the intake. They are likely full
>of carbon and crud, which is what is causing the problem. Pull the valve
>off and use some stiff wire or cable to run down the passages. Once you
>have it cleared out go get a can of SeaFoam or GM top cylinder cleaner
>and run it through the engine. That will dissolve more carbon and allow
>it to blow out of the engine through the exhaust. The easy way to use
>either one is to pull the brake booster line off and allow the engine to
>draw the cleaner in. Let it draw in about half the can or until the
>engine stalls. Then shut off the key and let it set for 20 minutes or
>so. Dump the rest in the gas tank. Now start the engine and take it for
>a drive to burn off the cleaner and blow the crud out. It will generate
>a LOT of smoke and spray soot and carbon out the tailpipe. DON'T USE IT
>IN A GARAGE or enclosed area. Make sure the tailpipe isn't aimed at
>anything that you don't want covered with carbon and crud.

Hey Steve... no Kleenscreen suggestion?

I put one in my 95 Blazer about 1 year/10,000 miles ago at your recommendation
and haven't had an EGR problem since..

Thanks again!

mac

Please remove splinters before emailing

[dan]

>>
>> I just replaced the EGR valve in my 99 Suburban (K1500 - 5.7L) …
>> again. I am wondering if there is something else that I should look
>> at. I would imagine that the new valve could fail as well (because
>> there may be some other problem)
>>
>> I was getting a P0404 code about 6 months ago (I have a code reader).
>> The car had typical EGR issues (rough idle, surging …) I removed the
>> old factory original EGR valve and cleaned the mounting area up (it
>> was not particularly dirty) and replaced the EGR valve and gasket with
>> a unit from Pep Boys. The brand was BWD I believe. The truck
>> immediately ran fine and the check engine light stayed out for the
>> last six months. The 99 Suburban uses one of those linear/electronic
>> EGR valves, and they are expensive (~$120 or more depending on which
>> part you buy).
>>
>> A few days ago the truck turns on the check engine light again. It's
>> that good old P0404 code (EGR Performance). Indeed the truck is again
>> exhibiting EGR like issues (surging, particularly at lower RPMs). The
>> idle was not rough, but the truck was surging just like when the other
>> valve was bad.
>>
>> I bite the bullet and buy a new EGR valve (since it did seem like the
>> EGR was bad). I removed the 6 month old EGR valve and cleaned the
>> mounting area up (it was still clean) and replaced the EGR valve and
>> gasket with an identical unit from Pep Boys. The truck immediately
>> runs fine again. I don't know whether the check engine light will
>> stay out … but the truck does run perfectly fine again.
>>
>> I will search for my receipt for the old valve since I believe it is
>> still under warranty. However, I wonder if there could be something
>> else that could be causing the EGR valves to fail. Any thoughts,
>> cause this could be expensive if I have to put in a new EGR every 6
>> months.
>>
>> Thanks,
>> Dan
>
>You need to clean out the passages in the intake. They are likely full
>of carbon and crud, which is what is causing the problem. Pull the valve
>off and use some stiff wire or cable to run down the passages. Once you
>have it cleared out go get a can of SeaFoam or GM top cylinder cleaner
>and run it through the engine. That will dissolve more carbon and allow
>it to blow out of the engine through the exhaust. The easy way to use
>either one is to pull the brake booster line off and allow the engine to
>draw the cleaner in. Let it draw in about half the can or until the
>engine stalls. Then shut off the key and let it set for 20 minutes or
>so. Dump the rest in the gas tank. Now start the engine and take it for
>a drive to burn off the cleaner and blow the crud out. It will generate
>a LOT of smoke and spray soot and carbon out the tailpipe. DON'T USE IT
>IN A GARAGE or enclosed area. Make sure the tailpipe isn't aimed at
>anything that you don't want covered with carbon and crud.[/color]

I looked into the passages to see if there was any crud. I stuck my
fingers in there. The insides were black. However, there was no real
thickness to the black stuff, just a light coating. I have some
trouble believing that this would cause the problem ... but I suppose
it is possible.

Thanks
Dan

[dan]

>>>> I just replaced the EGR valve in my 99 Suburban (K1500 - 5.7L) …
>>>> again. I am wondering if there is something else that I should look
>>>> at. I would imagine that the new valve could fail as well (because
>>>> there may be some other problem)
>>>>
>>>> I was getting a P0404 code about 6 months ago (I have a code reader).
>>>> The car had typical EGR issues (rough idle, surging …) I removed the
>>>> old factory original EGR valve and cleaned the mounting area up (it
>>>> was not particularly dirty) and replaced the EGR valve and gasket with
>>>> a unit from Pep Boys. The brand was BWD I believe. The truck
>>>> immediately ran fine and the check engine light stayed out for the
>>>> last six months. The 99 Suburban uses one of those linear/electronic
>>>> EGR valves, and they are expensive (~$120 or more depending on which
>>>> part you buy).
>>>>
>>>> A few days ago the truck turns on the check engine light again. It's
>>>> that good old P0404 code (EGR Performance). Indeed the truck is again
>>>> exhibiting EGR like issues (surging, particularly at lower RPMs). The
>>>> idle was not rough, but the truck was surging just like when the other
>>>> valve was bad.
>>>>
>>>> I bite the bullet and buy a new EGR valve (since it did seem like the
>>>> EGR was bad). I removed the 6 month old EGR valve and cleaned the
>>>> mounting area up (it was still clean) and replaced the EGR valve and
>>>> gasket with an identical unit from Pep Boys. The truck immediately
>>>> runs fine again. I don't know whether the check engine light will
>>>> stay out … but the truck does run perfectly fine again.
>>>>
>>>> I will search for my receipt for the old valve since I believe it is
>>>> still under warranty. However, I wonder if there could be something
>>>> else that could be causing the EGR valves to fail. Any thoughts,
>>>> cause this could be expensive if I have to put in a new EGR every 6
>>>> months.
>>>>
>>>> Thanks,
>>>> Dan
>>> You need to clean out the passages in the intake. They are likely full
>>> of carbon and crud, which is what is causing the problem. Pull the valve
>>> off and use some stiff wire or cable to run down the passages. Once you
>>> have it cleared out go get a can of SeaFoam or GM top cylinder cleaner
>>> and run it through the engine. That will dissolve more carbon and allow
>>> it to blow out of the engine through the exhaust. The easy way to use
>>> either one is to pull the brake booster line off and allow the engine to
>>> draw the cleaner in. Let it draw in about half the can or until the
>>> engine stalls. Then shut off the key and let it set for 20 minutes or
>>> so. Dump the rest in the gas tank. Now start the engine and take it for
>>> a drive to burn off the cleaner and blow the crud out. It will generate
>>> a LOT of smoke and spray soot and carbon out the tailpipe. DON'T USE IT
>>> IN A GARAGE or enclosed area. Make sure the tailpipe isn't aimed at
>>> anything that you don't want covered with carbon and crud.[/color]
>>
>> I looked into the passages to see if there was any crud. I stuck my
>> fingers in there. The insides were black. However, there was no real
>> thickness to the black stuff, just a light coating. I have some
>> trouble believing that this would cause the problem ... but I suppose
>> it is possible.
>>
>> Thanks
>> Dan[/color]
>
>You would need LONG fingers to reach down to the head/intake area where
>the carbon builds up.[/color]

OK, so it looks like Steve was correct. The new EGR valve fixed the
problem for two months .... WooHoo. The check engine light is on
again. A few days before the light came on, I was starting to feel
"EGR" like problems (a little surging, particularly at lower RPMs). So
it looks like those EGR passages need cleaning. I did not read the
OBDII code yet ... but I'm all but certain it will be a P0404 code.

I don't really want to run Seafoam or GM Top Engine Cleaner (TEC)
through the engine since I'm kinda worried that all that burning crud
could cause problems. I'm guessing that like it or not, I will have
to do the cleaning anyway.

From what I read, after running TEC through the engine I will need to
change the plugs and the oil. I am also kinda worried that it could
hurt the catalytic converter ... all that smoke going through the
converter does not sound good to me.

So as a preliminary fix I got one of those Klean Screen gaskets. I
will clean the valve carefully with carb cleaner (without getting any
cleaner into the electronic portion) and see if that buys me any time.
If that does not work, I'll get the cleaning done.

Thanks again,
Dan

[Steve W.]

dan@somewhere.com wrote:

> OK, so it looks like Steve was correct. The new EGR valve fixed the
> problem for two months .... WooHoo. The check engine light is on
> again. A few days before the light came on, I was starting to feel
> "EGR" like problems (a little surging, particularly at lower RPMs). So
> it looks like those EGR passages need cleaning. I did not read the
> OBDII code yet ... but I'm all but certain it will be a P0404 code.
>
> I don't really want to run Seafoam or GM Top Engine Cleaner (TEC)
> through the engine since I'm kinda worried that all that burning crud
> could cause problems. I'm guessing that like it or not, I will have
> to do the cleaning anyway.
>
> From what I read, after running TEC through the engine I will need to
> change the plugs and the oil. I am also kinda worried that it could
> hurt the catalytic converter ... all that smoke going through the
> converter does not sound good to me.
>
> So as a preliminary fix I got one of those Klean Screen gaskets. I
> will clean the valve carefully with carb cleaner (without getting any
> cleaner into the electronic portion) and see if that buys me any time.
> If that does not work, I'll get the cleaning done.
>
> Thanks again,
> Dan
>

The gasket will stop the carbon chunks from getting into the EGR and
sticking it open.

The TEC won't hurt anything. It DOES generate a bunch of smoke when it
goes through but it won't hurt anything (provided you don't decide to do
the cleaning right after the neighbors put all their clothes out on the
clothesline, or in the middle of a BBQ with friends, then you may have a
problem ;-)).

Yes on the oil, The plugs wouldn't have to be changed unless one of them
bridges with carbon after the treatment. The reason for the oil change
is to flush out all the carbon that will go past the rings.

I do the treatment every other oil change on the 97 and the 02 just as a
prevention. Also do it on a lot of other vehicles. It really helps.

Good Luck.

[mac davis]

>The gasket will stop the carbon chunks from getting into the EGR and
>sticking it open.
>
>The TEC won't hurt anything. It DOES generate a bunch of smoke when it
>goes through but it won't hurt anything (provided you don't decide to do
>the cleaning right after the neighbors put all their clothes out on the
>clothesline, or in the middle of a BBQ with friends, then you may have a
>problem ;-)).
>
>Yes on the oil, The plugs wouldn't have to be changed unless one of them
>bridges with carbon after the treatment. The reason for the oil change
>is to flush out all the carbon that will go past the rings.
>
>I do the treatment every other oil change on the 97 and the 02 just as a
>prevention. Also do it on a lot of other vehicles. It really helps.
>
>Good Luck.

For sure!
Steve turned me on to the Kleenscreen gasket a few years ago, and it stopped the
EGR problem completely...
I bought 2 so I'd have a spare and so far the first one is still working great..

mac

Please remove [dot]splinters before emailing

[dan]

On Wed, 16 Apr 2008 22:18:59 -0400, "Steve W." <csr684NOT**********m>
wrote:
>The gasket will stop the carbon chunks from getting into the EGR and
>sticking it open.
>
>The TEC won't hurt anything. It DOES generate a bunch of smoke when it
>goes through but it won't hurt anything (provided you don't decide to do
>the cleaning right after the neighbors put all their clothes out on the
>clothesline, or in the middle of a BBQ with friends, then you may have a
>problem ;-)).
>
>Yes on the oil, The plugs wouldn't have to be changed unless one of them
>bridges with carbon after the treatment. The reason for the oil change
>is to flush out all the carbon that will go past the rings.
>
>I do the treatment every other oil change on the 97 and the 02 just as a
>prevention. Also do it on a lot of other vehicles. It really helps.
>
>Good Luck.

OK, I verified that the code was indeed P0404. I bit the bullet and
did the top engine cleaning. I went to the GM dealer and tried to buy
TEC. They told me that it is not made anymore and gave me the "new"
replacement called "Upper Engine and Fuel Injector Cleaner" -
#88861802. I rigged up nice little funnel arrangement and slowly
poured the stuff in through the brake booster line.

Ultimately I poured the whole container in there and let the truck sit
for an hour. I started it up and it did the white smoke thing. I
decided to drive the truck rather than smoke out the neighbors. It
did seem to make a lot of white smoke. I also did some driving at
wide-open throttle. I forgot just how anemic the old 5.7 really is.
In any event, I can't tell any difference. . The engine still had
some EGR like symptoms … stumble/surge when you give it a little gas …
just off idle. Otherwise the truck runs OK ... not great … but OK. I
will change the oil tonight ... spark plugs seemed to be OK

Next, I took my previous EGR valve that I had cleaned with carb
cleaner … lots and lots of carb cleaner. I put that in with the Klean
Screen. I also cleared the P0404 code (so the check engine light is
out … for about a day or so). I can already tell that the "cleaned"
EGR valve is no good. The engine still stumbles/surges when you give
it a little gas … just off idle. So … I went to the store and bought
another EGR valve. I already know that when I put the new EGR valve
in the engine will not stumble/surge at all (since I have already done
this … twice before). .

My best guess is that none of this will have any long term effect. In
two months the new valve will be fouled. It would be great if the
cleaning and/or the Klean Screen solves this problem. Only time will
tell.

Thanks,
Dan

[mac davis]

>My best guess is that none of this will have any long term effect. In
>two months the new valve will be fouled. It would be great if the
>cleaning and/or the Klean Screen solves this problem. Only time will
>tell.
>
>Thanks,
>Dan

Dan.. I had different symptoms, besides the "check engine soon" light, the real
rough idle and no power brakes at idle, nothing else was effected..
The truck ran fine except at idle, brakes were normal unless at idle, (and after
the first pedal push and release), and the fuel economy was normal..

I took the EGR valve out twice and both times the pin was frozen from carbon..
After putting the Klean Screen in, it's been trouble free for about 2 years
now..
Hope yours is too!

mac

Please remove [dot]splinters before emailing