Ros,

Things I'd be looking for:

1) Broken Exhaust Bracket allowing a bit more movement in the exhaust at
certain revs.

2) Broken Exhaust Rubber that some cars hang the rear of the exhaust is
allowing more movement of the pipe to vibrate at certain revs.

3) (Faint Possibility) Failing engine mount is allowing the exhaust to move
more than it should, and allowing the exhaust to hit.

4) Exhaust is falling to pieces (has the car gotten any louder??)

5) A piece of rock or dried mud has been flung up and is wedged between the
exhaust & the body\frame somewhere, and makes the car sound like its falling
apart.  had one of these on my landcruiser a few weeks ago, and initial
thought was the bloody thing was coming to bits!

6) Last one is the cheapest to fix.  Take it to an exhaust person first;
they may be able to either fix the problem, identify it further, or point
you in the direction of someone who might be able to help you further. Most
simple repairs to exhausts arent worth much, unless they have to replace the
whole exhaust.  If its just welding a bracket, it would be unlikely to cost
you more than $25-30, depending on how easy it is to access. Either
replacing a failed engine mount or replacing the whole exhaust would be the
2 most expensive options.

Cheers,

Rod.......Out  Back

Oh you guys...

thanks for all the suggestions, I'll do the exhaust check option i think...
I don't think it's the rubberband, I replaced that last year...

ros  ;))