Boneyard

posted earlier question with no response-try again. '96 3100 82000 miles-started knocking this winter (1st winter with the car) on cold start- ups. Cold start ups(anywhere from 0-45 degrees) are in the morning or after sitting 4-5 hours. Car sounds like a diesel when knocking, which will last for about 2-3 minutes, though it seems like I hear a faint knock even after that. I use 5w-30 pennzoil and change oil every 3000 miles. I have read that this is common amongst these motors?? T or F?? Should I get this looked at or fixed? What can I do to shut this up, or is it normal? Car runs great once ticking/rattling/knocking goes away. anyone ever experience this??I Love my GP-hate the cost to fix it!!!!!!!!!!!!!

troy1

ITs more than likely piston slap Gm has problems with it my 95 3.1L does it and its got 124K. The piston has high cleanance when its cold and being made of aluminum is expands at a different rate the the block, wrist pin and connecting rod.

jon95se

my 95 makes the same noise. it actually isnt piston slap. it is the timing chain. a known problem with the 3.1L... the timing chain starts to slap up against one of the guides and makes that knocking noise. sounds like piston slap tho. got mine fixed for $600

Ridenour

Could also be lifter tick. Oil is very solid-like when it's cold out, and takes a long time to get all the way up to the lifters.

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radeck

I have the same problem on my 3.1 se. If you really wanna fix it, go ahead. I just learnt how to live with that and it's been already like 50K miles since it started.... so it's up to you.

Boneyard

thanks for the help-Sounds to me like I should continue doing what I have been and drive it!