Slag, Couldn't it also be chain noise/slap due to a faulty/leaky tensioner? Oil gets to the tensioner, it expands the piston(in the tensioner)and retightens the chain and sound gone. Just a thought.

Cheers,
Mark

 

Yes.. it could be any number of things. But the noise described along with occurrence at cold start up is a classic piston slap symptom. If it is piston slap, don't expect a remedy anytime soon... this tends to be a costly fix and is argubly a "normal" condition.

 

Maybe, but I don't think so. I am a mechanic and have heard lots of noises over the last 38 years,including piston slap, but it is nothing like this noise. By the time I got out and opened the hood, the noise was gone. Piston slap would do it everytime you started the car. Mine has done it twice in 500 miles. Once I get my car back from the dealer, I will have a good look/listen and let you know what I think it may be.

 

And that was a classic Troll Slap!

 

Smacked me down like a R56 spanking a Sentra!