EGR Valve making a knock...?
 

2 weeks ago i was told i had a rodknock, but i decided to get a second opinion. I took it to another shop, and they said my EGR valve had a leak, and was the cause of the knocking sound i heard. It's coming from the underside (stuck my head out the door while driving to pinpoint it) on the drivers side. Which would make sense, because the EGR valve picks up the exhaust in that general area. Last night i took the valve and piping off to inspect it, and i didnt find any cosmetic damage. I did find out that my steering column left a 1/2in dent in my header, but thats another story. Anyway, i replaced the gasket, cleaned it out with carb cleaner, ran it for a little bit and still nothing. The EGR isnt really old, and it didn't look worn. Is it possible for it to even make a knocking noise? Id like to make sure before i go and buy a new one, i've been told they're expensive...

Thanks~

RE: EGR Valve making a knock...?
 

Yeah the EGR could make noise with a leak. Before I went and bought a new one I would make a plate the shape of the gasket and drill the 2 bolt holes in it and use some high temp silicone and bolt it in place of the egr gasket. However if the valve gasket is not blown I don't see how the valve could leak. The EGR valve gets it's exhaust from the drivers side exhaust manifold in the rear of the manifold. Perhaps something has rusted, either the pipe feeding the valve or the area where the pipe is held in place in the exhaust manifold, a threaded nut that fits on the end of the flanged EGR pipe.
I would run the car and listen closely for a leak but it will get hot quick so check quicker! If you know a person at a garage have the car put on a lift and you can get a better look at the pipe and where it attaches or try getting the car on jackstand at home and use a creeper to get under and see if there is a leak. Good Luck aND LET US KNOW WHAT YOPU FIND. MARK

RE: EGR Valve making a knock...?
 

i do believe its not a rodknock hence we dont have pushrods my egr valve did the same thing replaced it no probs since.

RE: EGR Valve making a knock...?
 

It could be a spun rod bearing. If you really want to eliminate the EGR as the problem take it off and run you car. It will run like crap but if you still hear the knock start looking for a new engine.

RE: EGR Valve making a knock...?
 

You don't believe it's rod knock because we don't have pushRODS? Did you know we have connecting RODS? There is not a condition called pushrod knock, that would be called lifter knock. We sure can have rod knock though and that would warrant a rebuild. I have a feeling he has a problem with the EGR because a second opinion suggested that. The first guy probably knew it was an EGR and wanted to take our friend for a ride down scam road. Check out the EGR but remember you could have a rod knocking nonetheless. Mark

RE: EGR Valve making a knock...?
 

Thanks for the replies. All today i've been experimenting with it. Made a little plate to take the place of the EGR, capped the threaded rod on the header, ran it, still knocked. I inspected the EGR in it's entirety and nothing looked cracked/bent. I had a friend come over with his auto-stethoscope, we didn't hear a knocking from any of the cylinders. Like i said before, the knocking is coming from below the car somewhere. Problem with that is, we cant hear it unless the engine is under a load. At about 2200 RPM, it's audible. The only thing i have to go by is driving it with the door open and leaning down. I'll keep this updated, tomorrow i'll be switching out a borrowed EGR to test. Hopefully that ends well... Thanks again

RE: EGR Valve making a knock...?
 

::Update::

Well im still at square-one. Soaked my EGR in carb cleaner, didnt work. Did the same with the pipe, with the same results. The test EGR i was supposed to get wasnt the right fit (I figured an EGR off a 98 would be atleast close to a 99..). Last thing I did was a quick vaccum test on the EGR balloons and the entire rear side is immobile, so i'm concluding that the EGR is indeed bad. I'm just hoping that fixes my knock. Final post will be after i order and install the EGR. Ill try and get an audio file up here beforehand so you guys with similar symptoms can check what mine sounds like. Until next time~

HELLLPPPPPP
 

Did you find out if it was the egr making the noise mine doing the same thing!!

EGR Valve making a knock...?
 

Boltt, you had the right idea to clean the EGR valve, but the carb cleaner may have caused damage to the sensing unit in the EGR. I was building a nasty chevy small block for a cool Malibu. To save money the customer wanted to reuse the EGR valve. I cleaned the valve with carb cleaner and screwed up the EGR valve. From then on, only new valves are installed, or if the unit was not old, I will only use EGR Valve Cleaner. Yes, some will say they are the same, but I learned the hard way to clean the EGR valve with the proper cleaner. As far as price goes, I believe you can pick up a replacement valve from Late Model Restoration (LMR) for $59.99. For that price I would just replace the EGR valve and be done with it.

you can test the egr