Squeaking noise towards rear

[George 206cc]

Hello

In the first 4 or 5 minutes of driving from cold, there's a squeaking noise coming from the rear of the car. Driving at a very constant smooth speed (even over bumps and potholes) it's pretty much silent. The noise only occurs on the instants of pressing the accelerator or brake pedal, as the car moves longitudinally relative to the wheels/axles. (In other words, the sound only occurs when the car moves relative to the axles, it is silent when the acceleration of the wheels is in equilibrium with the suspension forces joining the axles and the car). Note, the sound only occurs in the first 4 or 5 minutes from cold. Once warm-ish, it's normal. Hope I've described this okay...

I've had a few suggestions of what the problem might be. I've heard it could be the exhaust mountings or exhaust springs or something like that but I don't think this is the case because in fiddling with the exhaust by hand trying to move it about, it can move slightly but doesn't make any noise. So, next suggestion, rubber bushes(?) around the ends of the springs in the suspension. It doesn't particularly squeak when going over bumps BUT, when I sit on the edge of the boot to change my shoes, it can squeak sometimes. Next suggestion, the handbrake. Not sure how the handbrake works on our cars but if it's one of those where it's like a separate drum brake in the hub, it could be rubbing. Again, can't be the case because it's not a constant squeaking, only as described above.

So, to conclude, I have no idea where this squeaking is coming from. If anyone could shed any light whatsoever on this, I'd really appreciate it!

Thank you

George

[Luditus]

The engine rocks on its mountings when under acceleration or deceleration, causing the flexible joint of the exhaust system to rotate. Stiction of the gasket (which is probably corroded) prevents this being a smooth action and results in a resonance along the pipe, which sounds similar to creaking ships' timbers. The noise goes soon after the joint warms up, or gets lubricated by rain water. Well, that's my theory, for what its worth!

[George 206cc]

Thanks for your reply, that's interesting. How would I go about fixing this? Do I need a new gasket or something like that? Is it something I can do at home or should I give it to a garage to do?

[Luditus]

Grovelling around exhaust systems has never been a pleasant task, and one that I avoid as much as possible. In your position, I would sneak up on the car with some WD40. Spray the flexible joint, then start her up and see if the squeak has gone (or at least diminished) when you drive off. If this test proved positive, I would then go to an exhaust fitting place, and ask them to fit a new gasket (and any other bits that are shot). Also, get new exhaust hangers fitted - they are usually free. These people have all the facilities, and the muscle to do the job. You have a coffee from the vending machine, pay a paltry sum, and its all done - hopefully.