Help! My 4.8is won't run
 

I don't know what's wrong with my 06 4.8is. Last Wednesday while driving home in the rain my X5 began surging and running rough. When I stopped at a traffic light it stalled and would not restart. I had it towed to my local BMW mechanic and he has not been able to find out what's wrong with it, he says that the computer is not throwing any codes. He mentioned that it might be a problem with the air intake system. He said that I might need to have it towed to the dealership. Does anybody have an idea of what may be wrong? It is out of warranty and I need to get it fixed.:dunno:

Could be the mass air flow sensor, or your fuel filter. Simple test: try unplugging the mass air flow sensor and see if it runs? It will default to a fixed setting an should run. If so, replace it.

either your maf sensor like flatlander said or its your cam sensors. dont take it to the dealer, take it to a mechanic who works on bmw and run a diagnostic. you can replace these sensors, whichever may be yourself. good luck.

hi
 

Hi.

this happened to me once. I was driving and it stopped at the stoplight. It was an ignition problem and they had to switch out the ignition switch.

Not sure if this might be your issue but worth looking into.

-Saul

Update on 4.8is
 

Today I went to the shop of the BMW mechanic that had my X5 since last Wednesday. He again stated that he did not know what was wrong with my X5 but did give me a bill for $360. I mentioned the mass air flow sensor to him and he said that he thought about that and unplugged it. He said that it still wouldn't start. He said I should take it to the dealership. He said the $360 was for a drive motor for variable intake which he replaced. That obviously was not the problem. He said that it may need a new intake manifold. Am I liable to pay a mechanic if the vehicle isn't fixed? He never told me that I would have to pay for parts or labor if he couldn't fix it. I have to go to the dealership at this point.

The dealership called today and said the problem is the fuel pump. Thanks to everyone for your help.:thumbup:

The Damn fuel pump. No warnings, no start problems. Just goes off and nothing you can do about it! it sucks! but it's not hard to diagnose one after it has failed: starter is turning and it wont crank up.

LOL- you have a horrible mechanic. No start and fuel pump is auto mech 101.

LOL. actually no, he checked with some electronic amp voltage checker or whatever you call it. However I did diagnose one after my friends Audi didn't start up right after my fix.