Originally Posted By: Pontual
Originally Posted By: CKN
Originally Posted By: Pontual
40 seconds in a cold engine represents about 1,500 plus reciprocations (idle high rpms) with maybe lack of lubricant.Id address this asap.
It's been pretty much narrowed down to piston slap and not lack of lubrication.....
Narroed down to piston slap ... By whom, you? Not even heard the noise ... fine
FYI piston slap go out when the engine gets warm enough, thats above 2 minutes, not half minute.
Piston slap has been so common in so many thousands of engines that most people routinely thing a cold start rattle is piston slap. Because most of the time it is and GM was the king of piston slap for years. Some Toyota Tacomas do it. Heavier oil can sometimes reduce or stop it. I heard it in my Tacoma for only a few seconds once or twice and went from 5-30 to 10-30 and haven't heard it since. As for how long it takes to disappear? I'd bet that has a lot to do with the size of the piston and how colds it is. Hypertuetectic pistons and the short skirts on them are the culprit, If the clearances aren't just right they rattle until they expand enough. You can Google it. It's very common with many manufacturers and various engines. Hypertuetectic piston technology is getting better and better so piston slap isn't as common as it was back in the 80's and 90's when they first went to the Hypertuetectic cast pistons. Back in the 80's GM had big problems with them and had oil consumption problems because of them as well. Thank your government.