Piston slap or wrist pin noise 02 C5

[hotmtrsports]

I brought my 2002 at a Chevy Garage under the GM extended warranty and asked them to check on a knock when first started and for about 10 minutes afterward. I made a copy of the front and back of their work order when the diagnosis was completed.

The tech wrote:
"Checked engine noise, had very slight knock. Sounded like piston slap or wrist pin - did not sound abnormal. Pickup O'ring in oil pump does not seem to be the problem. Doesn't make alot of ticking noise."

The GM rep said he did not hear it. Everybody else did and since when is a piston slap or wrist pin noise normal or acceptable??? The service writer said they have replaced quite a few truck 350 engines only for the knocking to return in about 20,000 miles. What gives. The service writer also told me that about 5 other Corvette owners are complaining about the same thing. Don't we have the GM V8 pretty much perfected by now!!! I believe they are not going to be easy as far as paying for this and want me to go through a few hoops first and I understand that.

Has anybody out there gone though this and what can you recommend my next step be.

I have 59,500 miles on it and the extended warranty will expire at 60,000 miles...don't dare go over the 60,000 miles even though the service writer told me it's been documented and not to worry about it...yeah right!!!

Thanks for responding,

Chuck

 

[c4c5specialist]

HI there,
I would suggest that you might need a decarbonization of the engine.
High carbon content on the top piston ring land could create the condition, even though you have the teflon coated pistons.
That is what I would suggest.
This will NEVER create a reliability issue and once the decarb is done, you will notice a gain in power and better drivability.
The root cause is the garbage gas formulas that are out there, along with the cool temperatures that the cylinder heads run, combined with using high octane fuels.
Allthebest, c4c5

 

[Val]

If you have the money I would renew that extended warrenty.