Strange noise

[bigscotia10]

I've got a strange noise when I'm in slow traffic. It's the same sound you get when driving over a manhole, sounds like this video: http://www.brentwoodgazette.co.uk/VIDEO-noisiest-manhole-cover-Essex/story-19014831-detail/story.html

 

It happens when slowly increasing acceleration in first gear, and appears for only a second or two. It also appears when reversing slowly. As well as when turning in gear, with no power on the accelerator. And when breaking while car is moving really slowly, while in neutral.

 

I can only hear it with the windows down. And only happens on occasion. And as far as I can tell, it's coming from the back of the car. It's also hard to replicate as it doesn't happen every time.

 

Anyone else experience this or ideas?

 

Update: I am able to reproduce it when coming to a stop, then starting again. Happens both when slowing down and accelerating. Both when my foot on and off the clutch, or in neutral. Also happens with my foot both on and off the brake.

 

Thanks!

 

2006 997S

Edited March 5, 2015 by bigscotia10

[White987S]

Water pump?

Serpentine belt?

Pulley?

 

What is your maintenance history????

[bigscotia10]

Nope, doesn't sound like any of those. Maintenance history is good, just had one about 4k ago, with new water pump, pulleys, and belt.

 

It sounds like something is loose under the car, or at one of the wheels. Def a thin metal sound. I'm going to take a look at the break calibers, wheel joints, under belly, and make sure everything is torqued.

[jl-c]

Sounds like brake pads moving in the calipers. I have had this in the past. Are the dampers still attached to the pads? Other thought is that it might be the handbrake shoes inside the rear discs? Loose lining or one has become detached?

Edited March 5, 2015 by jl-c

[White987S]

Exhaust clamps?

Motor mounts?

Damaged muffler baffle?

 

Do you have PSE?
 

Edited March 5, 2015 by White987S

[bigscotia10]

Awesome, thanks for all the suggestions! will add that to the list to check.

 

Yep, I have PSE.

[bigscotia10]

Is there anything in the clutch that could make that noise? When the clutch is engaged, or disengaged.

[jl-c]

I think a worn pressure plate could possibly make that noise if a finger was broken. JFP I am sure could confirm or deny.

[bigscotia10]

Cars in the shop, but think that was it. The clutch went out, so it's getting replaced. I have a feeling thats what the noise was.