I'm getting engine noise, seems like the pistons, when I start up my engine cold. The colder it is, the louder the noise. Is this normal It seems to go away after it warms up. Could it be the type of oil i'm using? I switched from Pennzoil (never a sound) to Havoline (sound started) and recently Mobil 1 Syn (sound still occurs) ; all 5W30 with AC DELCO filter.
I was told by someone that it's my oil not remaining on the pistons or something
Any help or advise would be greatly appreciated

 

I think that this is a classical case of cold engine knock. It's common in the LS1's. You have nothing to worry about.

Anyone correct me if i'm wrong.

Thanks,
Jonathan

 

yeah, thats right ... It's common in LS1 engines!

 

i dont think its that common cuz neither me or my friends get it

 

yeah i dont get that...and it gets really cold in chi town

 

GM calls it piston slap. Rather than calling it engine knock which is generally considered bad. I have heard it is pretty normal for stock LS1's and my car does it too in the mornings for about a 1/4 mile. Then it goes away. I fyou are getting knock when your ECT is more than 150 degrees, then you have problems.

 

Thanks for the replies. Yes, it goes away when the temp gets over a 1/4 reading.

Dan

 

I have a 2000 LS1 I dont hear a noise... Just to let you know btw it has 30000 mi on it sorry if i wasn't help

 

oh i see.......the notorious piston slap

 

I had a 97 Seirra Z71 with the 5.7(350). It had the same thing. Until I got my 99 Z28 and found this board I was freaked also. Just let your car warm up for 5-10 minutes.