Everytime I go over 4500rpm the engine seems to stal and the service engine light comes on. I then have to stop shutdown and when I start the car back up the shakes are gone but the light stays on. I have taken the car in to a cert. BMW mech. he check the flow meterbecause there was a lean air reading but that check ok, then he found the PCV hose broken that was replaced but it keep doing the same thing.The computer also showed that the #5 coil was misfiring he put in a new one that did not fix it. After doing all this troubleshooting by what the computer was diagnosting, he saying that it has to be the catalytic converter. Please tell me if you know about this problem happening before.
Q&AAsk Your Question
2006 BMW X3
Question: why does the service engine light comes on and tremble when I go over 4500rpm's
Answer #1patrick mannion from Greg Solow's Engine Room, November 07, 2011, 18:55Master
There are tests to follow for each code. A professional grade scan tool shows freeze frame information when the code occurred and has live sensor data. These features are only as good as the person interpreting the information. The ignition coil failure could certainly cause the misfire and vibration but the coil has to be properly triggered by the computer. Put the failed col into another cylinder and see if it then triggers a misfire in that cylinder.There is a professional service called Identafix. http://www.identifix.com/info/about_us.htm They only deal with professional repair shops. They are in the Minnesota 651-633-8007 begin_of_the_skype_highlighting 651-633-8007 end_of_the_skype_highlighting. Your auto repair shop do all their diagnosis tests, and discuss your problem with a team of professional technicians great service cheap and very bright people. If the repair shop that are repairing your car are stumped this is a great service. This company only deal with automotive repair shops and don't answer questions for the general public but are an amazing knowledge base.
Replycarita, November 08, 2011, 19:38Rookie
Thanks Patrick, My mech is pretty good he ahs lots of experience but this gremlin is making him scrach his head more than once. He's moved the coil to a diff cyl, installed a new one, checked the wires he also found a hole in the PCV hose(replaced it) cleared all codes but the service engine soon light comes back @ 4500rpm's and also the vibration. I do the same thing shut it down and start it right up the vibration goes away but the light stays on and it still reads #5 cilynder misfire. I've gone to other Bimmer blogs and I found out I'm not alone on this trip. Some refer different models and engines with the same bank 2 lean air problems with misfires at #5 or #6 or both. Some mech-techs say that it could be carbon build up at the inlet manifold, and to clean them or to replace the crankcase ventilation hoses and gaskets. But the funny thing is that I did not read about anyone actual fixing the problem with the misfire at bank 2. Also none griped about the vibration at high rpm's. Could it be the gasoline filter being clogged? Anyway thanks for the website, I'll let him know about it.