Morning Folks,
As I posted earlier about a lock issue and am logged into the forum, figured I may well ask about this.

About a week back I got into the truck (2002 GMC Jimmy SLS, 4 door, auto) and when I first turned the key there was a loud clunk/thud sound (it did shake the truck, so yes I felt it as well). Needless to say it grabbed my attention. I immediately got out, popped the hood and looked to see if I could see any problem. Nothing. Looked underneath the truck, nothing.

Got in and started it, no problems. Been driving a week since and nothing. The truck is driving fine, accelerates fine, not leaking, etc.

Anyone else ever run into this issue? Anything specific I should be looking at or having my mechanic look at when I take it in next?

Cheers for now,
Scott

 

scan the computer. Mine had something like that while starting. I actually replaced the starter but the issue persisted. Turns out my ICM was bad. Causing the engine to misfire when cranking, ran great otherwise and you would never know.

I had a hidden code for the icm sitting in there with no CEL.. worth a thought. Other thing could be the cap and rotor, but it depends how old that is.

 

Thanks for the advise.

I am dropping new spark plugs in her today, and next month I figure I will do the ICM, cap and rotor just to be on the safe side.