Can anyone help with this one?

When I'm stopped at stop lights, etc., there is what I can only describe as a random clunking coming from somewhere under the middle of the car - every two or three seconds, but not regular. It sounds like something metal and quite solid is actuating, but I have no idea what it might be. No other symptoms seem evident. Any ideas? It's very much like the clicking you get when a hot car is cooling down and metal is contracting, but this is about ten times louder - something is definitely clacking too and fro.

Thanks in advance!

 

The first two things that come to mind with odd clunks from beneath the car are prop shaft and exhaust.

Check the prop shaft UJ bolts for tightness at both ends and the Jurid coupling (item 2) for degradation:



On the exhaust system, apart from loose heat shields, check the rubber hangers (items 4 and 5):



If these split, then metal to metal contact can create odd clunks.

Graham

 

As Graham says it sounds to me like an exhaust mounting bush.

 

Thanks guys, I'll get out and get under!