Odd Rattle

[sick boy]

Hey all. I have this odd rattle that sounds like a loose heat sheild, but it's coming from under the valve cover. It only does it at certain RPM and when I lift the throttle. Does anyone have a clue as to what it might be?

It's a KA24de, and at first I thought it was a PCV valve but I don't think it is now. Oh, and does anyone have an exploded view of a KA that I can look at?

[01mmmz28]

find someone with a car stethascope (sp?) That will help pin point the noise better. Under the valve cover.....Hmmm.....cracked valve spring is my guess.

[sick boy]

it's toward the front of the valve cover if that helps. there is a vacuum hose that comes off the intake tube and goes to an metal elbow on the valve cover, the rattle is coming from around that or the timing chain.
im just trying to avoid taking it to a shop that will try and rip me off and still not fix it.

[01mmmz28]

got any friends that are car guys? because diagnosing an under hood rattle can be tricky sometimes, as sounds resonate off of metal parts. You could possibly have sheared some teeth off the timing chain sprocket. Not good either. Get it checked out soon.

[JGT8229]

try and get a video of it

[sick boy]

sorry don't have any way of getting a vid.

i've used a screw driver against my ear to try and find it. i hope its not sheared teeth. i baby it and it's still running good, so i don't think its that. i'm thinging its just a loose chain. she's got a dr's apointment friday morning so we'll see.

[v_dub_ya]

If that chain breaks bad news

Like z28 said, valve spring or a rocker arm?

[sick boy]

it doesn't have rocker arms, it's dual over head cams. sorry i didn't say it was in my 240sx.

[sick boy]

hey it ended up being a loose timing chain slapping a useless guide. Nissan put out a notice that the guide causes noise problems and can be taken off without hurting the engine. so there ya go, thanks for the help.