1987 EGR Valuve Question

chuckndonna67 · 10-24-05, 08:32 PM

I am a newbie with my first Vette, 1987 Convert. I have a constant check engine light (code 032/code 044) which according to Autozone usually means an EGR valve will take care of this. Apparently for the 1987 there is more than one part number. Being a self starter I would considering replacing this if I knew where it was to get the part #. Even with the service manual I can't exactly pinpoint its location but feel that the EGR valve is covered with some sort of plenum. Any ideas of where and how to get to it? Thanks

Edmond · 10-24-05, 09:44 PM

The EGR is right underneath the plenum and the plenum will have to be removed in order to get to the EGR.

First, you'll have to unbolt the throttle body from the plenum. Then you'll have to take off the connections at the rear of the plenum. Then, there are the vacuum lines on the passenger side rear of the plenum. And also the retainer for the TB cables.

Before you lift the plenum up, there are connections on the bottom of the plenum so don't lift up too much.

The EGR is held in there with a couple of 3/8" nuts. It confused me at first because the rest of the bolts are metric. You may find access to the EGR bolts to be difficult if you don't have "crows feet" sockets.

If it's your first time, you can do it in an hour.

chuckndonna67 · 10-24-05, 09:52 PM

Quote:

Originally Posted by Edmond

The EGR is right underneath the plenum and the plenum will have to be removed in order to get to the EGR.

First, you'll have to unbolt the throttle body from the plenum. Then you'll have to take off the connections at the rear of the plenum. Then, there are the vacuum lines on the passenger side rear of the plenum. And also the retainer for the TB cables.

Before you lift the plenum up, there are connections on the bottom of the plenum so don't lift up too much.

The EGR is held in there with a couple of 3/8" nuts. It confused me at first because the rest of the bolts are metric. You may find access to the EGR bolts to be difficult if you don't have "crows feet" sockets.

If it's your first time, you can do it in an hour.

Edmond thanks! After posting my thread I went in search of Code 32 threads and found this is a very common problem (seems like I would have learned this from my vacuum experiences with an '87 Jeep Wrangler) One must have the proper tools I gather to get this plenum/EGR off. What may take someone 1 hour will take me 2-3. Wonder whether I should just take this to a mechanic who knows vettes? Thank again. CHUCK

Edmond · 10-24-05, 11:10 PM

Chuck,

It isn't that hard to do. The reason why a first timer would take longer is because a first timer should be a little more careful with the process the first time. I've taken my plenum off a few times.

It's a very straightforward operation, nothing tricky about it with the possible exception of access to the EGR nuts.

If you take it to a mechanic to knows 'Vette's, you'd better make sure he's adept to working on the TPI Corvette's.

With shops charging in the $80 an hour range and probably marking up the price of parts, I would take the hour and change it myself.

tigmaned · 10-25-05, 08:37 AM

i am going to be doing mine as soon as the AcDelco EGR and EGR noid come in from Rockauto.com. and since i did the T/B by pass i can leave it on the pelnum. i am not getting a code but i think it maybe the reason i fail emissions at a idle for high hydrocarbons.

Inertia 500 · 10-25-05, 12:42 PM

I just replaced the EGR valve on my '86 recently. A few things to look out for:

If the plenum has never been off before, the gaskets between the plenum and runners, (the tubes connecting the plenum to the intake manifold) will be stuck in place and you will find it impossible to remove the plenum without loosening or removing the runner on one side. As I recall the shop manual says to loosen the runner on the passenger's side. They are a little easier to get off than the driver's side. I know because I took off the driver's side, which required removing the distributor and the cold start injector. There is a "hidden" screw on each set of runners that attaches them to the intake manifold. You must remove all the screws securing the runner to the plenum and intake manifold before it will come loose. For the passenger side runners, look underneath the plenum, sort of behind the thermostat housing. On my '86 there is an EGR soleniod and connector in the way that you will have to remove to get to the hidden screw.

Whatever you do, resist the temptation to whack the runners with anything to loosen them. The may look robust, but they are actually very thin, soft aluminum tubes and you can dent them!

I recommend getting new plenum to runner and runner to intake manifold gaskets ahead of time because you will need them. I think I bought an entire set from Eckler's that included every gasket you need.

Take your time, don't get frustrated, and don't be surprised if you find some more stuff that needs repairing once you get into this project. I found that the electrical connector for the EGR solenoid was broken. I also replaced various PCV hoses while I could get to them easily.

Another thought, if your valve covers are leaking, or you want to repaint them, now would be an excellent time.

Good luck!

tigmaned · 10-25-05, 01:17 PM

were did you find the EGR solenoid connector??? i know mine is broken too, i can see it and half the time its not hooked up after a drive, BUT it doesn't throw a code??

Inertia 500 · 10-25-05, 02:40 PM

Tigmaned,

I bought it from my local Chevy dealer. It cost about $25 but it's the only place I could find one. I used the new connector housing with the old pins so I wouldn't have to splice the wires.

tigmaned · 10-29-05, 12:58 PM

you know i found some thing funny with my EGR system. the connector from the ECU to the EGR silenoid is not the greatest shape, basisly just the two metal prongs sticking out. well today i went for a ride and i disconnected the wires going to the EGR silnoid and about 20 or so miles of driveing and i didn't get a flash from the dash, so i am not getting a code for that being disconnected? whats that mean my vettes not going into close loop??

WNH · 10-29-05, 02:05 PM

Quote:

Originally Posted by Edmond

The EGR is right underneath the plenum and the plenum will have to be removed in order to get to the EGR..

Here's a visual of what the plenum looks like when removed.
The EGR valve is in the middle.
If you are doing work like this for the 1st time, take digital pictures, they come in handy.

85vette · 10-29-05, 02:29 PM

thanks to all who have posted especially with pics!
I will be doing this in the spring

jiangtao · 10-29-05, 03:06 PM

Before you go to all the trouble of changing the EGR valve you should change the EGR temp switch on the EGR tube. Mine kept giving me a code 32 and it turned out that the switch/heat sensor was bad. I changed it and everything was OK after that. One more thing, the heat sensor isn't one piece. The wire going into it screws in and if it's loose you will get a code 32 also.

tigmaned · 10-30-05, 04:57 AM

wayne88
did you get the pelnum off with out loosening the runners?? i have never taken that off yet.
i think i am going to change my EGR system, i am not getting any codes, but for grins i disconnected the wire going to the EGR solenoid and still no code??
ED

WNH · 10-30-05, 08:41 AM

Quote:

Originally Posted by tigmaned

wayne88
did you get the pelnum off with out loosening the runners??

I loosened the bottom bolts on the runners so the plenum could slip out.

When you put the plenum back on, hand tighten the top runner bolts into the plenum at first. The plenum is soft aluminum, the threads strip easily.

Edmond · 10-30-05, 10:07 AM

I managed to take the plenum off without loosening the lower runner bolts. But that looks to be the exception more than the rule.