Engine at 1000-2000 RPM sounding like a Diesel.

[russiansohcf23]

I started the car this morning and it sounded like a diesel like there was some knocking going on. I let it warm up a bit and it still sounded like a diesel. Can someone help me out, like what could be the reason why its doing this?

Thanks.

 

[finch13]

Could be valvetrain noise... could be a spun bearing knocking. Post a video.

 

[HondaLuver83]

Could be "teh piston slapz" lol. Does it go away when warm? Valvetrain noise will sound like clattering, a knock will be distinct clunk.

Remember, as the crank rotates one time the cam rotates twice. So you can kinda judge the speed of the sound.


A bad crank bearing is possible, but I'd like to think that only happens to boosted people and from running out of oil.