Small rattle from underneath...

[Cadeez]

It's killing me, I HATE rattles! It happens at idle intermittently, not always, just here and there, warm or cold. It sounds like the heat shield of a cat rattling from underneath the cockpit, however there is no cat or heat shield there. If I blip the throttle even just slightly it goes away, sometimes for "good" (meaning until I go), sometimes I have to hit it a couple times. It also happens just the slightest bit as I start to take off, when the clutch is almost 100% at the top. Something is rattling, I need to find it and fix it...STAT! Any ideas fellas?

[az3579]

It's killing me, I HATE rattles! It happens at idle intermittently, not always, just here and there, warm or cold. It sounds like the heat shield of a cat rattling from underneath the cockpit, however there is no cat or heat shield there. If I blip the throttle even just slightly it goes away, sometimes for "good" (meaning until I go), sometimes I have to hit it a couple times. It also happens just the slightest bit as I start to take off, when the clutch is almost 100% at the top. Something is rattling, I need to find it and fix it...STAT! Any ideas fellas?

Is it possible that it's just the very minor flywheel chatter that most ZHPs seem to have? Or does it really seem like something is loose?
I hear chatter sometimes (very very faintly) and I know for a fact it's my flywheel. Does the sound go away when you push the clutch pedal in (not moving)?

[Cadeez]

No I don't think it's the flywheel, that has a different more "tin-y" sound to it. This (to me) sounds like a heat shild rattling against the undercarriage or cat itself, or a rock in the heat shield, etc. I had this on one of my Jeeps, it sounds exactly the same, it's pretty distinct. It doesn't go away when I push the clutch in either. I've banged on the underside of my car's exhaust from the rooter to the tooter, nothing. And when it's on a lift you can't (or shouldn't) have the car running to replicate it. It's killing me...

[az3579]

No I don't think it's the flywheel, that has a different more "tin-y" sound to it. This (to me) sounds like a heat shild rattling against the undercarriage or cat itself, or a rock in the heat shield, etc. I had this on one of my Jeeps, it sounds exactly the same, it's pretty distinct. It doesn't go away when I push the clutch in either. I've banged on the underside of my car's exhaust from the rooter to the tooter, nothing. And when it's on a lift you can't (or shouldn't) have the car running to replicate it. It's killing me...

I'm trying to help you explore the non-obvious things it could be. Of course, you should check the obvious culprits such as a loose heat shield, but there are other things you may not even think of that could cause it. One perfect example is my E30; it once had some weird rattling that happened while at idle and sometimes when revving the car up. We checked everything underneath with the shop, until my brother said "check the motor mounts". Sure enough, checked and replaced, and the sound was gone!

If all of the obvious things check out (the only thing I can think of at the moment is the heat shield, but there certainly are more things to check), then I'd say look at the condition of the mounts.

[az3579]

Did you get a chance to figure this out?

[Cadeez]

Not yet, I haven't really had a chance to get on a lift and get underneath to bang on and shake things around. It's a bothersome rattle, but I know it's not hurting anything so I'm just gonna have to live with it until I can get to my dad's shop and get it up in the air.

[Mtnman]

The other day i had to tighten my intake airbox 9the two 10mm bolts that hold it down)....and that fixed a rattle. I was happy.