strange sound coming from valve cover

[O0ooAJoo0O]

ok, this one has been buggin me for about 2 years. yes, i said two years

At 3400 RPM i get a strange rattling sound coming from the valve cover. about 2.5 yrs ago i replaced the timing chain and nissan discontinued the top plastic guide, saying it was not needed. im starting to think it is. has anyone else had this problem? the sound continues through 3900 RPM, and then stops. when im pulling hard, IE racing, it doesnt make the sound, it only occurs when i let off the gas and let it rev down. it also occurs if the car isnt moving, or if im driving normally.

could the timing chain be loose? and rubbing the valve cover? i havent had a chance to look inside there recently. i have a KA24DE by the way. im just curious if anyone else is or has experienced this.

[Altiman94]

could be a rocker arm that is making your mysterious noise

[SinceByMan]

I cannot think of the right phrase to describe the sound so you can identify it but I think I had the same noise, it was like a tapping, like tapping sticks on something hollow, a mechanic said it happens when somebody puts too much oil in the engine, just one time, and the noise is there to stay, the mechanic said it would go away if I had my cylinder head reshimmed but the noise isnt harmful so I left it alone, it will quiet considerably if you use thicker oil. Oh yeah, I have no idea what Im talking about. Just my 2 cents.

[24_4life]

does it sound like marbles tapping togeather

[O0ooAJoo0O]

SinceByMan that sounds like it. but i know i have never put too much oil in, it has always leaked a bit, so its always low. i switch to 20-w50 about a year ago and it quiets a bit, but then comes back. this also happens when i fill the gas tank.

anyone else ?

[groundhogday1976]

What part of the valve cover is it coming from? SinceByMan might be right about the shims. BTW, DEs don't have rockers.

[O0ooAJoo0O]

the front, near where the timing chain is.

[groundhogday1976]

Did you replace both chains and the guides to each?

[O0ooAJoo0O]

both chains? i didnt realize there were two, my dad did the work. being it was almost 3 years ago and i knew nothing. i assume he did, since we got the kit from nissan dealership. the only thing that wasnt there was the top guide. which, like i said was discontinued.

[TachyonS14]

Maybe It could just be the lifters making noise ?

[O0ooAJoo0O]

im goin to video tape it with audio and post it in a couple days. right now im outa commission( i was trying to loosen a bolt on my celicas transmission, yep, ratchet slipped (explicit cursing/screaming/jumping) and i later found part of my middle finger on the ground. now that im home, i cant write too well, being right handed, and it sucks to shift :sad

[groundhogday1976]

Yeah, there are two chains. One is driven by the crank and is connected to an idler sprocket which in turn drives the upper chain which is connected to the cam sprokets. I saw in another thread you thought your dad replaced both since he had to take the oil pan off. However, he could've done that just to make sure any metal that may have fallen into the pan from your chain flying off was gotten out of there. I'd make sure he did both 'cause the lower chain has the same guide and tensioner issues the upper one has.