I recently bought a 2006 Audi A4 Convertible (2.0 TDi) through a private sale. The car has done 76,000 miles and has a full Audi service history.

Two weeks ago as I was driving and the 'oil pressure level low' warning came on - I took straight to the garage who thought it was the sensor which had gone as there were no other signs of failure, however when looked at further the oil pressure pump had broken.

I had it towed to an Audi garage as they said given it has full Audi service history they maybe able to make a contribution of between 30-80% of the repair costs which will be matched by Audi UK.

Having had the engine stripped down at a cost of close to £500, I have been advised that there are signs of wear to the engine and they will replace just the pump and turbo at a cost of £1895 (usually £2429) but they will not guarantee the engine, which they advise needs replacing at a cost of £8513.92 (usually £10083) - a fair way off the 30-80% contribution initially offered!

They say there is nothing else they can do to help as it is not a known fault and the car is out of warranty.

I see on your reviews of the car you flag up the fact that the 2litre TDI units are prone to sheering - suggesting that, contrary to Audis feedback, it is a common fault.

Have you come across this before and can you advise what I could do?