which part of the exhaust is most likely to vibrate against the floor?

[tim eh?]

It keeps happening after I have work done on the car - the exhaust vibrates against the underneath somewhere mostly in idle but often when I accelerate too. I'm pretty sure it's the exhaust - it's vibration not a hole and the exhaust is on pretty solid ie it doesn't budge when I play with it. Last time the vibrations went away but it is worse this time. This time the exhaust was lowered but not removed in order to replace the driveshaft center bearing. Just wondering if this is common and where to look/adjust, I might take it back if it doesn't settle down - I have a 2 year old Ansa muffler and resonator that used to be nice and super quiet.

[Ken35i]

I'm sure it's under the right-hand front drivers seat/floor area.

[Ferret]

On the 540 I had, I used to get exhaust resonance that would back up through the front mounts which were bolted to the gearbox. Took six months to figure out that it was mainly to do with the fact that one of the cats was bolted to the centre box about 5 degrees out of straight - and was causing the whole exhaust to not sit straight.

Took it apart (and took it for a drive sans cat back exhaust, oh man what a noise) and carefully bolted the whole thing up taking care to get it straight, sorted all the noises out straight away.

Usually the contact happens at the top of the cat/heatshield I've found, make sure your cat's bolted in straight.

[tim eh?]

On the 540 I had, I used to get exhaust resonance that would back up through the front mounts which were bolted to the gearbox. Took six months to figure out that it was mainly to do with the fact that one of the cats was bolted to the centre box about 5 degrees out of straight - and was causing the whole exhaust to not sit straight.

Took it apart (and took it for a drive sans cat back exhaust, oh man what a noise) and carefully bolted the whole thing up taking care to get it straight, sorted all the noises out straight away.

Usually the contact happens at the top of the cat/heatshield I've found, make sure your cat's bolted in straight.

I'm sure it's under the right-hand front drivers seat/floor area.

awesome I will check that - thanks!

[lilcallaway]

I would also recheck the center bearing. I remember not doing something correctly and it needing to be replaced again.

[wool]

Doubt it's thte exhaust unless you have a broken hanger, or one of the flexible hanges was replaced with some sort rigid metal hanger. When you replaced the shaft bearing did you notice any wear on the flex disc (guibo) ? When it begins to break apart it will cause vibration.

Wool

[tim eh?]

Well I ended up taking it back. It happened when they lowered the exhaust to replace the centre bearing. The cheapo exhaust bent upwards in the middle (just in front of the resonator and was hitting the floor). They bent it back - it still hits but a lot less... next time I am there I will get them to do it a bit more.... doesn't speak well for ansa exhausts, apparently it is nearly impossible to bend the real thing. Well, I guess I will start saving my soup cans for a mid-winter exhaust pipe intervention...