Mechanics

EGR VALVE

1994 Pontiac Grand Am

Engine Performance problem
1994 Pontiac Grand Am 6 cyl Front Wheel Drive Automatic 126, 00 miles

I have noticed that there is moisture or condensation in the manifold on which my EGR valve is mounted. The moisture is also indide the EGR. Where is this moisture or condensation comming from, and can it cause my EGR to malfunction? After changeing both oxygen sensor, and EGR valve, I have failed 2 emissions tests. Can you help?
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Jaef
April 13, 2008.




The moisture can be caused by the fact that hot exhaust and cool intake come together at the EGR valve. What are you failing on the emissions test?

Tiny
Jack42
Apr 14, 2008.
I 'm failing the NOx (oxides of nitrogan)
standard is 2.50 this time when I went it was 4.92

Tiny
Jaef
Apr 14, 2008.
Sounds like a lack of EGR operation. Try pulling th evalve on manually with car at idle, should almost stall the engine, if it doesnt the passages are plugged and must be cleaned out. Is this an all electric valve or does it have a vacuum line

Tiny
Jack42
Apr 14, 2008.
It is all electric

Tiny
Jaef
Apr 14, 2008.
No codes in the ECM?
AD

Tiny
Jack42
Apr 15, 2008.
I cant a scanner that goes back that far, and the port sems to be different than most(only has three places to plug pins into). Tried to ground out proper spaces in plug to creat a" 12" and get fault codes to come up, but no luck.

Tiny
Jaef
Apr 15, 2008.
Might want to call around and find a shop that has a GM-1 connector and can scan it for you, this could greratly help in the search for the no EGR condition. Does the engine run at the proper temp? If not it wont turn on EGR, must be at running temp for the ECM to use the EGR

Tiny
Jack42
Apr 16, 2008.
Had scan done, intake / Egr parts were carboned up pretty good, Egr was opening correctely but port(s)
wetre clogged. Had carbon cleaned out, hopefully car will now pass emissions, although service engine light did come on after driving 10 miles or so. Any ideas?

Tiny
Jaef
Apr 19, 2008.
Need to have it scanned again (sorry). Might be something related to the carbon running through the engine when the EGR passages were cleaned.

Tiny
Jack42
Apr 20, 2008.

AD