Mark Watson

Hi Experts, I have a worrying knock on my 2010 E93 Convertible. On start up I get a knocking sound for only a second then it disappears. The car runs and sounds fine..if I stop and start there is no sign of the knock. But if I leave the car for a few hours the knock re appears.. any suggestions or have you heared of the same problem.. thanks

Thanks for the info Dave...thought it odd about the regeneration, as my car is petrol not diesel, but he said it would reset the sensor...??? Ive topped up the oil so will try and see if there is any difference. regards Mark

Hi Guys, I need your expertise with a niggly problem I have on a cold start up. When I start her up there is a knocking sound from the engine area....I have been told by a BMW specialist that it is the NOX sensor. He advised me to regenerate by driving for 45 mins in forth gear at approx 65mph. I did this but it did not cure the problem. I have no warning lights and the car runs smoothly without any hesitations or coughs...Any ideas Regards mark. .by the way car is 2010 e93 320i convertible with 74000 miles