Recently our 120D's engine light came on - took it to the garage who said the codes said it was the glow plugs. they cleared the warning and left it with us. Within 24hrs the light was back on. They looked again and it was the same code so had three glow plugs replaced (not cheap!). They test drove it and all seemed fine, but then we picked it up, within 20mins the light came back on.
Car seems to drive fine, and to be honest the mechanic (who we've used for years) has said that they will relook at everything for us.
I'm wondering whether anyone has seen something similar before to help try to pinpoint this?
Car's got about 76k on it, and not sure if it's related or just coincidence, but the light came on about 2 days after we picked up the car from the garage after some work with a crack on an oil pipe.