Rattle Rattle

csmall · 06-15-2008, 09:59 PM

Hey folks,
For a couple months now I have an intermittent rattling sound coming from the engine compartment, only heard while the car is idling. My first guess was the balance belt knocking on the cam cover but after checking the belt tensions I'm convinced that everything is sound and this isn't the problem. I havn't been able to locate the sound even while inspecting with the hood up, though I have to admit I havn't crawled underneath yet with the engine running to take a look. Water pump perhaps? I've had no problems with overheating and I don't see any leakage on inspection. There dosn't seem to be any regularity to the sound, not appearing at set intervals although I do hear it every time I drive the car. Car is running great otherwise. Any thoughts?

bholmes · bholmes's Garage

Is it a rattle or a chirp? I'd go w/ exhaust for rattle and throw out bearing if it's a chirp.

aj951 · 06-16-2008, 07:39 AM

Does the rattle go away if you press in the clutch? I have a slight rattle when my car idles (when not in gear) but when I press in the clutch it goes away. I have read that it is the 5th gear rattling in the trans axle and transferring through the torque tube to the front of the car. I don't know if this is your problem but I thought I would throw it out there.

A.J.

hpservertech · 06-16-2008, 07:53 AM

Rattle wont be a belt. Rattles are usually metal related. Exhaust heat shields are known to cause this.

Cking1975 · 06-16-2008, 09:04 AM

I was wondering about that rattle ??? How do I get more info on the fifth "gear" rattle in my transmission...it is driving me crazy. I am thinking I will pull the transmission out this winter and rebuild it...sounds like a fun winter project.

csmall · 06-16-2008, 11:37 AM

I hadn't heard about the transmission rattle..... I seem to get this even without the clutch engaged..... it almost sounds like a moving part because of the sound does have a rhythmic quality when I hear it, thats why I originally thought it might be the belts... perhaps a better description is a tap-tap-tap-tap-tap in quick succession. I was thinking it might be a loose part that moves when the engine vibrates at a particular frequency during idle. I appreciate all the ideas.

aj951 · 06-16-2008, 02:18 PM

If it is more of a "tap..tap..tap" sound in the engine bay, then I would be more inclined to suspect a lifter/tappet is not pumping up with oil. Search the threads for "lifter or tappet noise", some of them have links to You-tube videos so that you can hear the noise and have a comparison.

A.J.

Dtchy · 06-16-2008, 03:50 PM

I had a rattle thinking it was something in the engine compartment. I figured out it was actually the right side headlight cover rattling during idle.

csmall · 06-16-2008, 06:36 PM

I sure hope its something as simple as a headlight cover. For those that have experienced sticky lifters: is it usually an intermittent problem or does it occur contantly? Is it something I would only expect to hear during idle?

PXJ800 · 06:00 AM

I've got a rattle, something was bouncing around in the cat. Usually happens when I give it a little gas from a stop, when the car rumbles the most. It's not the shields - I went tapping up the length of them and they're fine, but one little tick to the cat sets it off. It went away this weekend, though. Maybe it got re-stuck somewhere when I took it on the highway for a bit.