95 Blazer EGR question

95 Blazer, V-6, auto

Had a "check engine soon" light come on and had rough idle and no power brakes at low rpm.. Local shop removed/cleaned/replaced EGR valve and problem was cured, for about

300 miles and now it's back..

I've googled it and got a lot of info on carbon buildup, etc. and want to pull it and clean it.. my problem is FINDING it...

My Chilton's manual shows it as a large, one piece unit on the rear of the intake manifold, under the cowl. But on our engine, it appears to be 2 units, slaved by vacuum hoses, on the driver side of the intake manifold... The front module looks like a solenoid, the rear looks like a diaphragm in an old fuel pump... Can anyone tell me which part is the one that gets carbon deposits?? (assuming that I actually found the EGR)

Thanks.. mac Mac

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Reply to
mac davis
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It looks like this

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It should be on the front of the engine mounted almost horizontal right between the heads. Pointed toward the water outlet. It is easy to pull of without removing anything else. Except the electrical connector for the water temp sensor and the connector on the EGR. Remove the bolts, pull it out of the intake, rotate it so the flange is 90 degrees from install position then pull it out the front and then tilt the top up.

Pull it and clean the pintle of the carbon chunks. Once clean take a piece of stiff wire and run it into the port and break loose as much of the carbon as you can. If you want to stop this problem there are two ways. ONE is to manually remove all the carbon by pulling the engine apart and scraping it out. TWO is to grab a can of GM top cylinder cleaner, follow the directions on the can. One warning DON'T USE IT INDOORS. The other warning don't allow the exhaust outlet to point at ANYTHING you value since there is going to be a LOT of carbon and crud coming out that pipe. It will make you think the entire car is burning up when you see the smoke it creates. Once the treatment is done. Pull the EGR and clean it good, then install a Kleen Screen gasket instead of the normal one. It has a built in stainless screen that stops any loose carbon from getting into the valve. This also cleans out any carbon in the cylinders and will free up some of the crap in the rings as well. Because of that I also change out the oil and filter at least once after I use it, it is usually VERY black.

Reply to
Steve W.

Thanks for the reply, Steve...

I'm guessing that there must be several designs, as the URL you listed and the parts picture I downloaded are both different from our setup, as well as the picture in the chiltons... Also, it's installed (unless i'm looking at the wrong part) on the driver side of the intake manifold, towards the firewall.. The manual says that it's on the BACK of the engine, but there isn't anything there that looks like it has a vacuum hose going to it..

Here's a picture of ours, I should have done this with the original post:

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I think that the part in question is the round black part that looks like a little fuel pump with diaphragm? It had the same electrical connection that both pictures show, though the parts look very different...

Not a problem specific to Chevy.. I've seen this treatment mentioned in the Dodge group several times..

Will the screen clog, or is the carbon bounced back into the intake manifold?

Thanks again, Steve.. I really appreciate your help!

We love this little truck but my wife refuses to drive it until the idle/brake problem is solved..

Mac

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Reply to
mac davis

That is not the EGR valve. Your picture shows the the purge solenoid/valve for the evaporative emissions system. (not the same thing)

The EGR valve on a 95 Blazer doesn't have any vacuum hoses going to it, it is 100% electronic.

Your EGR valve is mounted directly below the throttle body and looks exactly like the picture someone else posted earlier.

Reply to
aarcuda69062

Thanks.. I had a feeling that I was looking at the wrong part..

I pretty much gave up wrenching when you had to be an electrician and plumber to GET to the engine, but since we're moving to Mexico, I want to be able to work on the blazer..

Please check on the link again, I removed the air inlet stuff and took a picture of what I THINK is the EGR... if it is, I'm thinking that the shop we went to didn't take it out and clean it, probably just used carb cleaner through the intake manifold of something... The clamps and connections on the air hoses looked pretty much undisturbed..

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Mac

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Reply to
mac davis

Yup, that's it.

Reply to
aarcuda69062

Yep that's the PIA... Anyway the screen blocks carbon from entering the valve and sticking in the pintle. GM did a recall on these valves and IIRC it involved them pulling the valve, cleaning it, then they flashed the computer to hold the valve open and cycle it to clear out the carbon. My 94 went through it and the EGR stuck open about a week later! I made a screen for mine and no problems since. Anyway, now that you have found it enjoy. Oh and with a little practice you can get the R&R time down to about 10 minutes on a HOT engine. Not really advised but when the EGR sticks open on a trip what can you do..

Reply to
Steve W.

Thanks, Steve & aarcuda... I really appreciate it..

Naturally, it started raining an hour ago! We NEVER get rain this time of year... there goes the deck staining project too.. lol

Mac

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Reply to
mac davis

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