Engine is idling high and squeeling. What is it?

Asked by Electronicsnerd Jul 20, 2014 at 12:45 PM about the 1997 GMC Sierra C/K 1500

Question type: Maintenance & Repair

I just bought a 1997 GMC K1500 Z71 with 5.0 Liter V8 and 4l60e transmission. The problem i am having is it idles high, about 1300-1500 rpm when in any park, neutral, and even in drive. If i have it in drive and let off the break, the truck flies forward just like i was hitting the gas. I can get up to third gear and 40 mph without even hitting the gas. When i try to get up and go, the truck feels like it has no power. It accelerates very slow. When the engine is warmed up, im getting a really loud squeeling coming from the engine. I know its not the belts because i replaced them and the noise didnt go away. I pulled off the PCV valve while the truck was running and the idle goes down and the squeeling stops. whats weird is where the PCV valve connects on the valve cover is sucking in air when i take the PCV valve off. I am very new to this stuff so any advice helps. and i also dont know lot about engines. Just a normal guy trying to fix his truck. I did have somebody tell me it could be a vacuum leak or an intake manifold leak. Any ideas?

2 Answers


You need to look for bad vacume line,s,check engine bay at intake,for loose or bad hose,s.

1 people found this helpful.

thanks. I think im going to take it to a shop because im not even sure where all of the vacuum lines are suppose to be. Maybe they can just look at it and see if one is broken or missing

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