Questions and Answers

GMC Suburban EGR Valve Q. Mr. Ciulla, I have a 1994 GMC Suburban V-8. It has about 182,000 miles. I have had relatively little trouble, with the biggest repair being valve lifter bushings replacement. Presently, at idle in gear, the engine acts as if it wants to die, but catches back up to idle speed, about 2,000 to 3,000 rpm.

At traffic lights it is very noticeable and actually surges some when catching back up to speed. At other speeds, the problem isn't noticeable. At idle, out of gear, the engine speed increases some and the problem isn't noticeable.

I'm thinking of changing the EGR valve and or having vacuum diagnostics performed. Please comment and suggest what is the source of my problem. Where is the EGR valve on this model?

Most sincere thanks!
Keith

A. It could be that the EGR valve is stuck partially open. This would make it run rough. It's located either behind or on the passenger side of the throttle body assembly. A black round metal can looking thing with a vacuum hose going to it.