saucymaro

Soo the other day my car started knocking when I turned it on in the morning. But when it warmed up the knocking went away? I'm thinking the valves? Any idea what else it can be? I also have a oil pan leak idk if that might affect anything? Thanks guys

KevinR

Sounds like piston slap. If it is, don't stress it, it's common with these cars

Pwhite11798

Piston slap

Pwhite11798

Its common especially in high miliage motors

KevinR

Yeah, it's common with GM vehicles. It happens because the clearance between the piston and the cylinder bore is too much, cause the "slapping" noise that you hear on a cold start. I'm not saying that's what your problem is, but if it happens only on a cold start, then goes away, I would put my money on it.

saucymaro

Thanks guys. But is it bad will it hurt anything else? And my car has 90k miles is it common at that mileage?

ShoddyHog

iTrader: (1)

Does piston slap happen "all of a sudden", or do you guys think the OP would have heard it gradually developing over time? I mean you don't just drive a car for 90,000 miles, wake up one day, and have piston slap, do you?

KevinR

Not sure. I know that I didn't notice mine until a couple of months after I got the car.

OP, it won't hurt anything. But again, that may not be what your problem is. Do you have a video of it you can post?

98hc4mula

iTrader: (5)

I have the same issue right now on a freshly built engine and I am having the heads taken off because we think its a lifter that is not pumping up and causing the noise. it increases with RPMs and its not there all the time. The oil pressure gauge trembles slightly so we think that it makes sense that the lifter is causing that oil pressure phenomena.

saucymaro

I can post a vid tomoro wen Im home. Have to work all dayy today ugh