Envoy engine knock at startup

I have an 03 Envoy and the engine knocks pretty loud for approximatly the first 5 minutes or until the engine completely warms up. I have tried to locate the knock and it seems to be real close to the fan. This has occured since I bought the car 3 years ago and the dealer can't seem to find a resolution. Any help would be appreciated.

Well, it seems most of these engines have " piston slap" cold, no problem with it, but is that the problem, what does the dealer say, normal or we can't find it?

They claim the inability to locate the knock. They don't think it's piston slap becuase of the speed of the knock. It's a slow (once per second) and steady hollow sounding knock.

So what now? Got any warranty left, if so get this in writing and if needed call customer service and insist on some kind of extended warranty on the engine.

I'm having the exact same problem. The dealer says he can't find the noise. Moreover he denies that the 03 Envoy I4 has cold piston slap problems. My extended warrantee is soon to expire. I have recorded the noise but the dealer says the mechanic has to hear it.

Welcome to AF, please look at the dates before posting in an old thread. Please start a new one, thanks. BTW, they do exhibit cold slap my 02 has always had it, assuming that is the actual noise.