ChatterBank1 min ago
BMW 3 Series
Answers
No best answer has yet been selected by hellbell73. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.I have little confidence in garage diagnostic equipment. It doesn't initially sound like a head gasket problem but it could be any number of things. You say it's just from cold ? Sounds like a bad sensor somewhere within the ignition system.
Not sure how much you like to get you hands dirty but go back to basics ;
Check that you are in fact getting a decent spark to each cyclinder
Check that you have no fuel supply problems
Check that there is a decent airflow into the fuel injection system I.e. no clogged air intake or filter.
Get a decent workshop manual such as Haynes and run any checks that it suggests to test the electrical elements of the ignition system.