I am working on a 1995 Chevy G20 Custom Van with a 5.7L (K) engine. The Service Engine Light came on so I scanned it. Forgot the code number but it was "Bad EGR valve". I replaced the old EGR valve, (17087196 020 52N) with BWD 103D. Every since I did that, it has been idling rough and sounds like a spark knock under the TBI. Running too rough to drive. Was running fine up till the time the Service Engine Light came on. Any suggestions? Thanks!!!!!!

 

are you shure you installed it right? sounds like it may be in wrong, the noise you are heraing may be the exhaust leaking through the egr valve gasket, some replacements need shims installed with it

 

How can you install one wrong? The new one is identical to the one removed. (As far as looks go) This motor only has 90K miles on it and until the EGR code came up, it ran fine.
Thanks for your help!!!

 

like i said some need shims, the sound you are talking about seems like a leaky egr, is the engine throwing the same code? you could also take the egr back off and look for black soot at the base of the egr, im not downplaying your abilities, just the fact that you are willing to tackle anything on your truck is saying a lot, most dudes cant check their freaking oil, and call AAA for a tire change, if the egr looks good, then idk what would be wrong with it without seeing it

 

Ok. Had to swap out the new EGR because it would not hold a vacuum. Also replaced the plugs. When I pulled the #7 plug the ground strap was bent up so I am assuming that something went through the cylinder. The new plug is still undamaged so it appears whatever it was passed through and out the exaust. But only after messing up either a valve or piston. Don't know what it was, everything I removed is accounted for.