I think my EGR valve is screwed

[3A-C Power]

Figure this one out:

My car has been hesitating and shaking since I bought it, and the fuel injection doesn't give any error codes and I tested for vacuum leaks with propane and none showed up.

Suspecting the EGR valve, I disconnected and plugged the vacuum hose and for a few days, it ran great, then started hesitating again. Then after a while I reconnected the vacuum hose, and for almost a week it ran great, with no hesitation at all.

It can't be my imagination, because this hesitation is quite noticeable. It causes the car to jerk violently at random intervals, so if that happens and then stops happening, I know about it.

should I just change the EGR valve?

[xirdneh]

Figure this one out:

My car has been hesitating and shaking since I bought it, and the fuel injection doesn't give any error codes and I tested for vacuum leaks with propane and none showed up.



should I just change the EGR valve?

sure sounds like a vacuum leak
when you connect and disconect hoses you may be disturbing something
causing it to leak or seal
maybe it was in sealed mode when you did the propane thing
are the nuts holding the EGR tight?
most EGR' s are clogged on high mileage motors
even as soon as 100K
my experience has been the cars run basically the same
clogged or not
rdw

[3A-C Power]

Fixed. There were actually 2 hoses going to the EGR valve, one from the standard vacuum modulator and one from the solenoid that forces it open under electronically sensed conditions. I had only unplugged the solenoid one before. Once they were both off, it stopped hesitating and it's been good for a few weeks. I guess it needs a vacuum modulator but I can't be bothered with that right now. It's nice after paying so much for a car not to be jerked around by the EGR valve all the time.

[3A-C Power]

Ok so nobody cares about my stupid EGR valve. But it's gone bad again after a couple months, same crap. Sure enough, connecting the hoses (both) resulting in a few days of good operation and now I have to disconnect them again. Just replace the valve? Checked for vacuum leaks again, still nothing, or if there is a leak it doesn't respond to propane.

[xirdneh]

[quote="3A-C Power"]Ok so nobody cares about my stupid EGR valve. But it's gone bad again after a couple months, same crap. Sure enough,




is your EGR valve clogged?
if it is
dig the carbon out
i use a screwdriver that has been sharpened like an oyster knife
squirting penetrating oil and oven cleaner and digging away will eventually
loosen it up
also check the intake manifold hole
it clogs up too
i kinda doubt the EGR is causing all your problems
are you sure a hose is not cracked?

cleaning EGR valve is messy buisness

[ARCHINSTL]

I made an addition to the EGR valve cleaning procedure.
It is in the Repair Guides section - with photos.
Tom M.

[takza]

If you apply vac directly to it at idle...the engine should quit or just about quit....if it doesn't...then I'd say it is clogged or it doesn't work.

[2wagons]

Hey 3AC,
Don't forget to check the metal tubes and vacuum lines for blockage. Mine were completely filled with the same gunk that I found in the EGR!

[3A-C Power]

Finally I couldn't stand it anymore, so last weekend I just BLOCKED the valve with a piece of sheet metal and some gasket paper. A new valve costs $380, a high price to pay for an experiment to find out if the valve was indeed bad. Of course there was carbon in it, but this one doesn't look like it can be cleaned easily. Everything is inside it. There's 2 holes, each going to a different port on the intake manifold, one leading to the exhaust (somehow) and one going up to where it connects to the throttle body. The holes are about 10mm and the valve is way in there. I can see the evidence of too much exhaust gas in the throttle body and the intake, so I took the opportunity to clean the throttle body up with some carb cleaner. I left the intake, not wanting to loosen up carbon to be sucked into the cylinders. With the EGR blocked it's been running smooth, and the hesitation is gone, however this is all too familiar. I'm waiting for it to screw up again, this time ruling out the EGR valve as the root cause.