In January I picked up a 2007 Golf R32 with 50,000kms. I got a check engine light along with a few issues with the transmission a few days later and it was repaired by the dealership. They replaced both the MAF and the Mechatronic unit.

I got the car back mid-Feb and have driven it 2500kms since then and the same fault has just returned. The car is due to go back to the dealer next week.

They're adamant (albeit via a phone call) that replacing the mechatronic unit again will solve the problem which I don't doubt, however I'm sure the unit should last more than 6 weeks/2500kms.

The actual problem I'm having is a fluctuating idle and the car turning off every 3 or 4 times I stop at traffic lights etc. The engine speed just drops til the engine stops, exactly as though you've brought a manual car to a stop without pushing the clutch in.

Has anyone else had any issues similar? Thankfully the dealer is liable for the repair but given that the previous repair (which they intend on doing again) lasted 6 weeks it'd be good to have an idea of what else may be wrong.