Noise from engine
My 09 ZO6 has 26K on it. About a month ago, it started making a distinct rat-tat-tat sound from the engine on initial start up in the morning. The noise would continue around 1400-1600 rpms primarily but heard up higher also. If I parked the car, shut it off and came back 1/2 hour later, the noise was barely audible if at all.
I've read the threads on valve train noise over and over. I took the car to the dealer where the guides were checked and apparently, no problem there. There was a bulletin regarding engine noise related to oil aspiration where the O ring in the dry sump tank would go bad, therefore causing the pipe in the tank to rattle. That was just replaced last Friday and the noise was very audible a day later. If the car sits overnight, the very next start up is very audible.
Might be on the wrong track but it sounds like a piston slap or knock, the warmer it got the more it went away.
Any thoughts, suggestion, or ideas that anyone has encountered regarding this issue? Please help(:
Pls read Rules of the Road re: Sigs