2000 GMC Jimmy Q&A

2000 GMC Jimmy Question: What should the RPM's be when my 4.3 liter engine is at idle?

Tune-up idle speed -
Answer 1
Idle speed is controlled by PCM. What problem are you having? -
Comment 1
Knocking at 600 rpm -
Comment 2
When you say knocking, do you mean an actual bootom end knock. If so that has nothing to do with idle speed. -
Comment 3
My 2000 GMC Jimmy makes a knocking noise after it warms up. There doesn't seem to be anything else wrong with it, it runs fine otherwise. I have asked several mechanics and they are stumped. I was told it could be a wrist pin? It idles at 700 rpm, is that too low? What else could cause a bottom knock? -
Comment 4
It is 12 years old. Not knowing how many miles are on the engine it could be an oiling problem. -
Comment 5
The idle speed is usually onthe underhood sticker with the engine/emissions info.Most are between 650-750 at idle in drive.If it's just one or two wrist pins as suggested while it's running kill one cyl at a time and see which cyl. the noise goes away at. -