WS6 engine knock

**christianjax** · 11-21-2006, 04:56 AM

I had a chance to buy a pretty mint 2000 WS6 Convertible. I backed out of the deal because the motor had a loud knocking after it had sat for a while. It went away after it ran for about 5 minutes. But it was there every time it sat for about 30 minutes. Since I was trading in a 99 T/A with basically the same motor I knew that wasn't "common". I had it checked out by a mechanic and since I had just driven it, it wasn't making the noise.
The dealer tried to tell me that LS1's were known for ticking and knocking. (guess mine was the exception huh?)
Anyone know if this IS common? It didn't sound like a lifter, it had a deeper sound than that.

**bwinch** · 11-22-2006, 04:11 AM

Its my understanding that it is kind of common in ls1's to have a cold knock when they start but im not an expert maybe one of the more knowledable guys will chime in.

**nhra-trans-am** · 11-22-2006, 03:31 PM

yeah, piston slap is pretty normal

**rajiv1998** · 11-22-2006, 05:46 PM

piston slap is common, but he said it lasts for about 30 minutes.

**bevenue** · 11-23-2006, 07:01 AM

my SS does the same thing. i don't know if its normal, but I think its common.

**YoMommasTA** · 11-23-2006, 03:49 PM

common,i looked at a 02 z28 that knocked exactly like you explain.I drove it,after 5 mins or so it was quiet.When it cooled off noise was there again.Piston slap.The dealer let me take it out for a drive,ran fine.

**svt_eater** · 11-23-2006, 03:51 PM

I believe there are tolerances in the design so that when the internals warm up, they are able to expand, and seat properly. This actually is by design, and may expand the life of your engine.

I am going from memory, but my car has done if from day 1, and I have heard many people discuss it in the past.