Metalic Rattle Sound From Engine Bay?

[lows_13]

Last night my car seemed to have developed a metalic rattle sound, it can be heard at idle but it seems

to disappear while driving. Its coming from the front of the engine bay, where all of the pulleys and

belts are. It doesn't seem to get louder or faster as the engine rev's increase.

The sound seems to be coming from the air-con unit.....

Edited May 29, 2006 by lows_13

[Cubes]

I had a really strange rattle from the engine bay that appeared to fade in at around 2000rpm then dissapear.

Turned out it was my alt belt was too loose, I can't say I've ever heard a loose belt cause a sound as such before, maybe the bearings in the alt are on their way out.

none the less check your alt/pwr/ac belts, rule them out.

[HRthirtyone]

timing belt is worn, it stretches and slaps against the cover. its very common in the rb20. It will be heard on idle, but when you rev it up the belt tightens and you cant hear it. Change it ASAP.

If u have recently had the timing belt changed and all your other belts are OK, then it may be the lifters

[lows_13]

It doesn't sound like a belt sound, its more metallic?

[lows_13]

I just ran my car at idle and turned the air-con on and off a few times

and the rattle went away. The sound almost completly disappears when the air-con is left on.