What have they botched now?

[GraemeSTL]

Had new exhaust ftted a week gone Saturday (1999 Bravo 1.6 HLX). Had MOT and service last Wednesday. Only since this weekend I've noticed that when decelerating at fairly slow speeds I suddenly hear a loud vibration from underneath. Sounds a bit like an exhaust blowing but also like a dull metallic vibration as if some clamp had worked loose - but I'm stumped as to why there's no problem while accelerating. Reluctant to take it in without a bit more ammunition as its not every time I decelerate, just occasionally, but when it happens it IS loud. Nothing to do with braking or clutch - happens on a straight too. What's the most likely thing they've screwed up?

 

[paul]

your car?

just take it in and tell them its not right.

 

[GraemeSTL]

Sure will . . .

Just curious to know why it happens on deceleration - it sounds like the exhaust isn't on right but I don't understand the physics.

 

[Mark]

It could be a heat shield coming loose underneath...

 

[Wimmy]

My guess is heatshield too. Coming from the rear of the car?

 

[Price Graeme]

And the outcome is . . .

The vibration WAS the exhaust against a heatshield but they tried adjusting it and fitting it again a few times which has dampened the noise but it hasn't gone completely - still get a hint of it at low revs. They asked if the car had ever had a hard impact. It had - on the rear wheel near the exhaust - because it looked slightly bent back there and whereas the impact must have bent the old exhaust in tune with the rest of the chassis, the new exhaust is NOT bent and so doesn't fit quite as well. It sort of makes sense and I wasn't charged of course, but endless re-adjustments may only end up making things worse.