I'm going to assume that this isn't a model specific problem and post it here but for the record it's a 2002 A4 3.0 V6 petrol convertible, multitronic auto.
I have a vibration that comes in at 17-18mph and goes away at 35ish but is at its worst at 20mph I can feel it through the steering wheel and the seat. It's quite subtle. It's there on acceleration and braking, sometimes it worse on braking, sometimes it's not there at all on braking. Still happens if I flip it into neutral.
I took it in to my local Audi specialist they checked all suspension bushes etc. and they were fine They found play in one of the CV joints which they duly changed, but this didn't fix the problem.
They didn't have time for further diagnostics so I took it away but the mechanic thought it might be a catalytic converter blocked up based on a slight whistle he could hear from the exhaust in that area. The theory being that blow back into the engine would cause the vibration. This doesn't make much sense to me as it would surely be worse at higher revs/speed and would affect the performance (which is just fine).
They didn't check the wheel alignment but I'm assured that bad alignment would not cause vibration.
I swapped the wheels front and back as they needed swapping anyway and it feels no different. (I would expect it to feel different if I had a buckled wheel and swapped front and back) Visual inspection of the wheels shows no damage and the tyres are all recent (they are always recent due to the rate it goes through front tyres!)
Before I go down the route of expensive diagnostics for the catalytic converter does anyone have any thoughts?
TIA
I have a vibration that comes in at 17-18mph and goes away at 35ish but is at its worst at 20mph I can feel it through the steering wheel and the seat. It's quite subtle. It's there on acceleration and braking, sometimes it worse on braking, sometimes it's not there at all on braking. Still happens if I flip it into neutral.
I took it in to my local Audi specialist they checked all suspension bushes etc. and they were fine They found play in one of the CV joints which they duly changed, but this didn't fix the problem.
They didn't have time for further diagnostics so I took it away but the mechanic thought it might be a catalytic converter blocked up based on a slight whistle he could hear from the exhaust in that area. The theory being that blow back into the engine would cause the vibration. This doesn't make much sense to me as it would surely be worse at higher revs/speed and would affect the performance (which is just fine).
They didn't check the wheel alignment but I'm assured that bad alignment would not cause vibration.
I swapped the wheels front and back as they needed swapping anyway and it feels no different. (I would expect it to feel different if I had a buckled wheel and swapped front and back) Visual inspection of the wheels shows no damage and the tyres are all recent (they are always recent due to the rate it goes through front tyres!)
Before I go down the route of expensive diagnostics for the catalytic converter does anyone have any thoughts?
TIA