01 Grand Prix Knock

69C20

69C20

Club Member
My car has a knock when i first start it up, it goes away once the car warms up and you cant hear anything even when revving the engine, I beleive that it is probably a rod. but why does it go away once warm??
Any info would be great, I bought the car at the end of summer when still warm, and there was no knock, but once it started getting cold out the knock started. I have put over 3500 miles on it since bought and the knock has not gotten any worse.If anyone may know why or what is happening could they give me some insight onto what is going on.

again any and all info would be of great help, Thanks in advance!!!
 
piston slap. let the car warm up a couple minutes before driving and it probably will never become an issue.
mostly cause by the very short skirts on the pistons.
very common on 3.1 3.4 4.3 ls1's
 
ok cool, I normally do let it sit and warm up, but my truck had a bad rod knock and it sounded about the same, so thats why I figured rod, but if its just piston slap, that makes me feel alot better, thanks man +1
 
ok sounds good to me, that would explain the whole it going away when its warm lol, not that I was trying to throw out your advice, just some more info lol.

Thanks again!!
 
Thanks a bunch guys!

Thanks a bunch that helped me out alot and now im not so worried i always lt it warm up before i drive it anyway so i think im in the clear thanks again!!!
 
my 3.8 had piston slap when i started it and after it warmed up it went away
(161,000 miles)

my brothers 3.1 is the exact same way (134,000 miles)

my buick 350(what the 3.8 is based on) is the exact same way @ 115,000miles

All three run great


you shouldn't be too concerned
 
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