Egr problem?

[Deusxmachine]

My 1990 will surge between 40 and 60 mph. Any thing slower or faster or when accelerating the car runs fine. When im on the highway ill get an code 32 egr. I just replaced the egr valve about a month ago. Are there any other things related to the egr that could be causing this. thanks for any help

 

[Edmond]

Make sure the lines aren't cracked in any way. The lines that old are bound to start cracking and breaking.

 

[vette-dude]

Did you replace the EGR valve with an OEM one or one of the universal type from an auto parts store?? Were the plastic lines and rubber connetors okay or cracked and hard (as previously mentioned)? Was the EGR switch mounted up by the thermostat housing working or did you check it??

If you used a universal type egr valve (which will hit the bottom of the plenum most likely) did you put in the correct sized washer provided with the valve?

Randy

 

[Deusxmachine]

I checked all the lines and replaced what was cracked, the egr is a part i got from autozone, looks just like the one that came off. I was wondering about the switch on the thermostat. How do you check it, i tried to order one from the net and autozone, niether place could get the part anymore.

 

[vette-dude]

I checked all the lines and replaced what was cracked, the egr is a part i got from autozone, looks just like the one that came off. I was wondering about the switch on the thermostat. How do you check it, i tried to order one from the net and autozone, niether place could get the part anymore.

There is a test for the switch using a digital meter but I do not remember the procedure. Maybe someone can look it up in their repair manual. I think the EGR switch is available through the OEM. I don't hold much confidence in EGR's from Autozone but that is just my personal preference. I got mine from the OEM. Are you sure the one you bought is the correct part number or did they just match it up with another model from some other Chevy? if so, it is wrong and may be the reason it throws the code. Otherwise if the switch checks good, the EGR is correct, and all vacuum lines are good I am at a loss to help you. Maybe someone else has the answer.

Randy

 

[RJS91RGTP]

EGR Problem

I had the same problem on my first Vette, a 91 ragtop and I could swear there were two EGR valves on the engine, one on each side of the engine block. I was told that should both be replaced at the same time. I have been out of the C-4s for a year or so and moved up to C-5 but my memory is pretty good. Check the other side and I bet you find the other EGR. Good luck and report back.

RJ

Suburban Chicago

 

[gmjunkie]

The new one probably has carbon in it!! I use 2 Gaskets with a Stainless Faucet screen sandwiched between them,it breaks up carbon so it won't get caught in EGR!!

 

[vette-dude]

I had the same problem on my first Vette, a 91 ragtop and I could swear there were two EGR valves on the engine, one on each side of the engine block. I was told that should both be replaced at the same time. I have been out of the C-4s for a year or so and moved up to C-5 but my memory is pretty good. Check the other side and I bet you find the other EGR. Good luck and report back.

RJ

Suburban Chicago

Only one on mine, right beneath the plenum at the rear. (91 Ragtop by the way).

Randy

PS: Good point Junk. Might be a piece of carbon stuck in the valve pintle on the EGR.

 

[RJS91RGTP]

EGR Problem

Vette-Dude, my memory must not be as good as I thought. It must have been my 96 coupe LT1 that has dual EGRs. I know I had two on one of my earlier Vettes.

Randy

 

[Edmond]

I thought the L98's only had 1 EGR with that being on top of the intake manifold right underneath the plenum.

 

[speedmaster4]

l98 only has one egr valve but its so hard to get to that you get double credit for changing it.

gmjunkie's tip about the stainless screen is THE HOT TRICK...do it

clean the pintle/seat of the egr valve before you reinstall it....if you stil have the original one its probably just in need of cleaning

 

[vette-dude]

Just as addendum. Most of the time it is the diaphram that goes bad in the EGR valve. To test this you can use a Mityvac or do it the old fashion way. You have to practice "ALTERNATIVE BREATHSTYLE" (smoking) to do this. Light one up, take a drag, and blow the smoke through the vacuum inlet port. If the smoke comes out around the diaphram it is ruptured. You can do this on or off the motor. Just watch where you flick your ashes!!!

Randy

 

[Edmond]

Nah, the EGR ain't so hard to get to. I have the art of getting to the EGR down to about 10 minutes.

 

[jmccloud]

40-60 mph surge

Check your plug wires. Perhaps by listening to an AM radio station or having someone watch TV nearby via an antenna connection (not cable). If either gives an engine RPM related noise, you probably have one or more bad plug wires. I've had 4 cars with this symptom (surge on standard transmission and bucking in and out of overdrive with auto); the first one cost $100 for the dealer to diagnose. Since then, I just replace all the wires and it eliminates the surge/buck.
Hope you find it.

 

[Blue89]

Are you serious about the 10 minutes?? Everything I've read leads me to believe that it would take a few hours to do it. I would sure like to know how to do it in 10 minutes to save the $350 labor the dealer wants to do it!!

 

[vette-dude]

Two hours or so. Edmond must have velcro on his plenum to do it that quick!!! Ten minutes, no way!! A little tip--put the plenum in the freezer while you are removing the EGR. With the new plenum gskts it is a little hard to install the plenum to the runners. If you freeze the plenum, it shrinks just enough that you won't have to loosen the runner bolts where they go into the heads. Install the plenum immediately after taking out of the freezer and start all the attaching bolts (I use antiseize on the threads but not necessary). Torque from the middle out to the end in a cross pattern. Suggest while you have the plenum off and before you freeze it to clean up the TB with throttle body cleaner -- DO NOT USE CARB CLEANER!!

Randy