Engine noise when cold...
12-07-2006, 11:52 PM
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Engine noise when cold... Ive been reading all the threads referring to the dreaded piston slap, but I know every situation is different and i wanted to put my mind at ease.
I just picked up my 99 z28 with 35,000 miles. As soon as i got it i drained the oil, put in mobil 1 5w30, a fresh K&N, new pcv... I drove it for a few days after i got it, and the motor sounded brand new perfect. Then just recently we had a snow storm, ice, freezing rain... the works. The car sat for a few days and wasn't driven. The temperature had dropped from the 60's to the 30's and maybe even lower. Now when ive been starting it in the sub freezing temps i hear a knocking/tapping for about the first minute and a half that I run the motor, and as soon as the temperature gauge starts to rise it goes away. What do you guys think this is. Should i be worried about the motor?
I've also heard that running some sort of top end cleaner (seafoam??) or switching to royal purple could help scilence the noise... is this at all true?
Thanks for your help!
I just picked up my 99 z28 with 35,000 miles. As soon as i got it i drained the oil, put in mobil 1 5w30, a fresh K&N, new pcv... I drove it for a few days after i got it, and the motor sounded brand new perfect. Then just recently we had a snow storm, ice, freezing rain... the works. The car sat for a few days and wasn't driven. The temperature had dropped from the 60's to the 30's and maybe even lower. Now when ive been starting it in the sub freezing temps i hear a knocking/tapping for about the first minute and a half that I run the motor, and as soon as the temperature gauge starts to rise it goes away. What do you guys think this is. Should i be worried about the motor?
I've also heard that running some sort of top end cleaner (seafoam??) or switching to royal purple could help scilence the noise... is this at all true?
Thanks for your help!
12-08-2006, 07:23 AM
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You will have an increase in noise due to the cold until warm up. Also keep in mind you are running a thin oil and that only amplifies the problem. I run 20w50 in everything (JUST PERSONAL PREF). Just be sure to let the engine reach operating temp before getting on it and you shouldnt have any probs.
12-08-2006, 12:25 PM
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I have a 2000 truck with the 6.0 L that I've owned since new. Each winter, I get some piston slap during initial warm-up then it goes away. The valvetrain is noisier when cold too. The truck doesn't use oil and makes good power. It's just a characteristic of engines with short piston skirts in my opinion. GM went to offset pistons and skirt coating to improve the situation.
In my opinion, it's not a problem. Once you accept that the engine is OK, it's not even much of a nuisance . . . just a characteristic of the design.
Steve
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Hope you enjoy the car!
In my opinion, it's not a problem. Once you accept that the engine is OK, it's not even much of a nuisance . . . just a characteristic of the design.
Steve
BTW
Hope you enjoy the car!
