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Re: How To Clean The EGR Valve

Did you check it before reinstalling it? Did the pintle valve move freely without sticking (opened or closed)? Did you pull any electrical connections and forget to plug them back in?
 

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1999 White Diamond ETC
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Re: How To Clean The EGR Valve

I cleaned mine with electronic contact cleaner, and a toothbrush. The electronics contact cleaner was extra insurance in case it managed to get inside the windings.

The thing is I still got the code a couple of times after putting it back together.

I performed the "carbon cleaning" via the intake vacuum with GM Top Engine Cleaner aerosol, then raising RPMs to 2000 and turning the car off when the smoke begins to come out.

A few WOTs later, no more EGR code. I think my pinging with cheap gas could have possibly been related to the EGR.
 

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1996 Deville Concours
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805 Posts
Re: How To Clean The EGR Valve

Would it be unwise to take some Seafoam or GM TEC and put a bit into the intake of the EGR while the car is running in order to clean out the hoses and the whole system? And if it is unwise, is it only unwise because it would damage the valve and nothing else? If so, I think it'd be a good idea to do before changing one (which I think I am about to do...).
 

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Re: How To Clean The EGR Valve

How are you going to do that? Where are you going to put it? Besides that, there is no EGR flow at idle. Just pull it and clean it the conventional way if you need to.
 

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1996 Deville Concours
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Re: How To Clean The EGR Valve

Well was thinking of holding the throttle lever open a wee bit...unless it has to be in drive, wasn't sure. I saw a vacuum line going to it...but calling up the diagram of the valve in my head, that might be bad for it and cause it to stop working, you're right. Might just put it in the return line with it off though.
 

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Re: How To Clean The EGR Valve

Tailfin said:
Well was thinking of holding the throttle lever open a wee bit...unless it has to be in drive, wasn't sure. I saw a vacuum line going to it...but calling up the diagram of the valve in my head, that might be bad for it and cause it to stop working, you're right. Might just put it in the return line with it off though.

Hey wait a minute. Are you talking Northstar? Different beast altogether. Pre Northstar you have to clean out the "mouse holes" inside the throttle body with an old wire hangar. Your proposed method is more orthodox, in that case. Do a search under the correct engine forum. There are plenty of posts on how to tackle the EGR code on a pre-Northstar.
 

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Re: How To Clean The EGR Valve

Wait a minute. "Mouse holes" are on '93/'94 Northstars. He has a 4.5. Mtflight, I believe you are thinking of the EGR "tubes" in the 4.9 tb bore.

That vacuum hose tailfin is discribing goes to the vacuum side of the EGR diaphram (no carbon there). Besides that, the pre Northstar EGRs rarely need cleaning.
 

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Re: How To Clean The EGR Valve

Ranger said:
Wait a minute. "Mouse holes" are on '93/'94 Northstars. He has a 4.5. Mtflight, I believe you are thinking of the EGR "tubes" in the 4.9 tb bore.

That vacuum hose tailfin is discribing goes to the vacuum side of the EGR diaphram (no carbon there). Besides that, the pre Northstar EGRs rarely need cleaning.

Ahhh! I stand corrected. :)
 

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1996 Deville Concours
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Re: How To Clean The EGR Valve

Yeah in retrothought, this doesn't seem like a bright idea. So I'm just going to crawl up the exhaust and...ok no...:bang2:
 

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Re: How To Clean The EGR Valve

I Am Reading Pcm;po171&po174 On The On Board Computer.my Problem Is Rough Idle Or Surging During Idle.what Does The Codes Mean.i Cleaned The Egr Valve But Only Used Carb Cleaner Around The Opening Of The Valve.how Far Do I Go?should I Push The Spring Loaded Valve Al The Way In?i Have A 2001 Deville.
 

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Re: How To Clean The EGR Valve

P0171 - Fuel Trim System Lean Bank 1
P0174 - Fuel Trim System Lean Bank 2

Vacuum leak maybe.

Yes, press the spring loaded valve all the way in. It should move freely and not stick anywhere along its travel. Clean the shaft as well as the opening, but don't allow carb cleaner to run into the "can" as it can destroy the insulating varnish on the windings.
 

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1994 CADILLAC DEVILLE CONCOURS, 350ZR
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Re: How To Clean The EGR Valve

Ok let me clarify or can you elaborate a little more. You want us to protect the canister by putting rag over it or by not spraying too much carb cleaner in the valve?
 

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Re: How To Clean The EGR Valve

94CaddyConcours said:
Ok let me clarify or can you elaborate a little more. You want us to protect the canister by putting rag over it or by not spraying too much carb cleaner in the valve?
When cleaning the EGR, hold it in the upright position as it is when mounted. Holding it inverted allows solvent to run down the shaft and into the "can". That is what you want to avoid.
 

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1993 DeVille
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174 Posts
Re: How To Clean The EGR Valve

GUYS........Once you have cleaned the carbon chunks out of
that EGR valve install one of these GM linear clean screen
gaskets with a screen to keep the carbon build up out of the EGR
Best $7 bucks I have spent!

I have used them in my older GM vehicles..................

http://www.tomco-inc.com
 

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Re: How To Clean The EGR Valve

I would not put that thing on my car on a bet. I can see the screen getting clogged and causing all sorts of drivability problems. The EGR passage is large enough so that it should never get plugged or need cleaning. That screen is not. That thing is a problem waiting to happen.
 

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1993 DeVille
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174 Posts
Re: How To Clean The EGR Valve

RANGER..........from all the posts I see here with clogged EGR valves
that gasket may well be a cure................

I used it successfully on my girls 4.3 Blazer which had many clogged
EGR issues because of the factory programming which didn't fully
open the EGR all the way thus causing carbon buildup and driveability
issues...............

My local indy repair shop now uses these screen/gaskets in several
different applications for older GM/Ford vehicles to cure carbon
clogged EGR issues..................

A good fix for $7 bucks IMO and experience and have NEVER had another
clogged EGR in her vehicle in the last 2 years!
Me thinks she need to BEAT on that vehicle a little to "clean" it out!
LOL!!!!!!!!!............geo
 

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STS 1994
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6 Posts
Re: How To Clean The EGR Valve

I cleaned my EGR valve thanks to the pictures in this post.
I had failed HC on the yearly inspection so I tried to clean everything in the enginecompartment. Did this, TB and plugs. No I'm back on the road again.
Thanks :thumbsup:
 

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Cadillac
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Re: How To Clean The EGR Valve

Hey Krashed989,

Thanks for the excellent post on how to clean the EGR Valve. I am a new caddy owner ('95 Seville SLS) and just pulled a few codes which brought me to this forum. (PO36 - PO39 - PO94)

THANKS!

edited: dont post questions in tech tips, please see sticky - urbanski
 

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1993 DeVille
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174 Posts
Re: How To Clean The EGR Valve

Guys.......If your tired of cleaning the carbon chunks out of your
EGR valve as I was from Grannys carboned up ride.
Check out this replacement EGR valve gasket that has a screen
moulded into it. Cost about $5 bucks.........geo

http://www.tomco-inc.com
 

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1999 White Diamond ETC
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Re: How To Clean The EGR Valve

I used electronic contact cleaner spray, instead of carb cleaner. It's a solvent that does not damage sensitive electronic parts.
That way if it does happen to get in the can, it won't harm it.
 
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