I hooked up my code scanner to my 97 LT1 and it said that it has an egr valve malfuntion, tried pushing on the valve while the engine was running and it didnt change the way it ran. Took the valve off and it seems that it is functioning properly. It also has a knocking that seems to be in the top of the motor but doesnt always do it, are these things related. And what else could be done to solve my problems. Please help if you can. Thanks

 

The EGR valve can "look like" it's functioning properly but it can still be leaking. Clean it out with some carb cleaner. How is your car running when you initially try to accelerate? If it hesitates and almost dies off the line I'd probably say that your EGR valve is leaking.

 

It does hesitate sometimes but not always. I will give it a shot. Thanks for the help.

 

I need some expert advice. I am also having issues on my 97LT1with my egr. I had the check engine light on last year and changed out my egr with a new Delco unit. Got the same light about 6 months later and changed it again with what looks like the same EGR valve but i bought it from a Chevy Dealer. Now i am getting the same light. AGAIN !!

But the strange thing is that i get about 2 mpg better when the light is on and my car runs better on 87 octane than 93???

So what up? anybody ever seen this before? should i just seafoam the Sh** out of my engine and hope all the carbon gets blown out? I dont see how build up can be that much after about 5000 miles.

 

i took out the "bad" egr Valve tonight and did a manual test. If you press the center pin all the way in and plug the nipple on the back it should remain stuck open? Correct? It pushes in just fine but won't stay that way. Does anyone know if that indicates the egr does not open at all?

 

bump

 

Lt4 module might help with the knocking
I hear the stock setting sucks (picks up any kind of knock even if it is just from you headers)factory canmakes you timming go up and down could be off around 11 degrees of timming

i just changed my fuel pump regulator and it stop the prob of bad idel and that little knock in the top of the engine that happen ever now and again