EGR Questions

[jshrop]

I have read through all of the posts here, and still have a few questions, maybe someone out there can help to answer them.

I have a 95 Jimmy, 4.3L 'W' motor. EGR valve code 32 was coming on, took the valve off, cleaned it out, there was a chunk keeping the valve open. The actuator came back out to all the way closed, and I reinstalled it. Now I'm pretty sure that the EGR actuator must have been damaged because it seems stuck closed now.

My questions are:
1.) Does anyone know if there is a way to test to see if the linear actuator is moving back and forth? Would it be ok to run the motor with the EGR valve off and the electrical connection hooked up? I can't think of anything that would be in danger of getting more messed up by having the port open while I test it, but then again, I'm not a mechanic.

2.) Can anyone who might still have a factory part, or know the factory part number post it. I have been getting the run around when it comes to ordering a new EGR valve, and getting quotes. The discounter that usually beats everyones prices says there are 4 different valves that were used for that model, engine size, and W code. My current valve is an aftermarket replacement, with no meaningful numbers on it corresponding to any of the OEM part numbers. Has anyone had any experience with this? Is this guy full of it, or are there really 4 different models and configurations for this same motor? These guys are too far to drive with the part and compare in person, but if I order and have it shipped free, I can save $40 over what I can walk into the parts shop locally.

Just a quick EGR/Exhaust note:
If you plug off your EGR valve, or are running with a damaged actuator in the stuck 'closed' position, you can put undo stress on your catalytic converter (if you're in one of those states, I'm in CA) and cause it to stop cleaning the exhaust, and furthermore cause your motor to run horribly. I have actually replaced the cat on mine do to this very problem, so make sure that if your valve is stuck shut, it won't run as hard as if it's stuck open, but it could cause more damage if you don't replace it.

Thanks for any help! I feel for you all, I think every part on my Jimmy has been replaced at least once!

[chembrad]

I popped a EGR gasket w/ screen on my EGR after I cleaned it out to keep carbon chunks from getting into the EGR.

And if you experience heavy carbon build up in your EGR, then you might want to check all the way down to the lower intake manifold. Chances are that you have carbon buildup down in the intake ports as well.

I'm not sure if this is "normal" carbon deposit (after about 100k miles) or just indicative of a problem.

[BlazerLT]

carbon is from a leaking cpi injector.

Did you reset the computer after you reinstalled the EGR valve again?

You have to do that so the computer can clear the EGR code and resume normal EGR operation.

[herkyhawki]

Do you have OBD2 or ALDL computer? If your computer is under the dash, there are different EGR valves. In 1995, it could be either one. Take VIN # to Dealer and get part number, then take the GM part number to parts store.

[chembrad]

Originally Posted by BlazerLT

Did you reset the computer after you reinstalled the EGR valve again?

You have to do that so the computer can clear the EGR code and resume normal EGR operation.

I had the battery disconnected for several weeks while I was working on the engine in the eves.

Doesn't this reset everything? I didn't get any service engine soon light after I repaired it. It has been running like a champ.

The only thing is the the coolant system was so rusted that I have to keep flushing the coolant every 2 weeks or so to try to get rid of all the rust scale that accumulated in the coolant path due to poor maintenance (piss poor mechanics who took advantage of an elderly couple imho).

I've driven it about 4,000 miles since the major repairs and I love it.

Next I plan on replacing the rear window motors. One is out and the other is weak.

[herkyhawki]

Originally Posted by chembrad

Next I plan on replacing the rear window motors. One is out and the other is weak.

For the window motor that is "weak"... Spray the track/seal on both sides of the window with graphite lubricant and it will then go up& down at normal speed. WD40 also works, but I don't know what it will do long-term to the seal material.

[BlazerLT]

Originally Posted by chembrad

I had the battery disconnected for several weeks while I was working on the engine in the eves.

Doesn't this reset everything? I didn't get any service engine soon light after I repaired it. It has been running like a champ.

The only thing is the the coolant system was so rusted that I have to keep flushing the coolant every 2 weeks or so to try to get rid of all the rust scale that accumulated in the coolant path due to poor maintenance (piss poor mechanics who took advantage of an elderly couple imho).

I've driven it about 4,000 miles since the major repairs and I love it.

Next I plan on replacing the rear window motors. One is out and the other is weak.

You should run a complete flush through it for a while to get all the gunk out and remember to replace the rad cap with something other than a AC delco version.

And yes, your computer was reset.

[chembrad]

I'm thinking the rad cap I bought was a Stant... I don't recall. I'll check later.

[chembrad]

And as for flushing the coolant system, I use a Prestone kit "T" installing in the heater core to raddy line. I disconnect the lower raddy hose and clamp closed the heater core to raddy line. Then I reverse flush the coolant system until it runs clear. Re-attach everything and then refill it with clean coolant. I believe it is working because it flushes clean faster and it is taking longer to get dirty brown.