Q I have a 53 plate E60 530i with 93,000 miles and full dealer history. I purchased the car in October, and since then I have taken it back to the dealer several times with the following problem – on cold mornings, the engine will hesitate and sometimes cough when pulling out of junctions. There is sometimes a flat spot after gear changes.

When accelerating under light throttle the car feels as if is losing power and sometimes feels as if there is a misfire. Under full throttle it feels down on power and sometimes will give the kangaroo effect throughout the rev range. It drives normally otherwise.

The servicing is up to date. It has been back to dealer several times, they have said that there are no fault codes showing, so there is no fault. They did however change the spark plugs when I sent a complaining letter.

Adrian Norman, email.

A We spoke to Parkside Garage (01909 506555) who thinks it’s the air mass meter. These often fail without bringing up a fault code – if the garage you bought it from won’t replace it, we’d fit one and get any fault codes cleared. This is a common problem and all the symptoms tally up. It could also be a split inlet boot – worth removing it and checking it thoroughly. Genuine units are £227 plus VAT – you can get them a bit cheaper aftermarket, but not by a huge amount.