BMW 320i - E46: Cranking but not starting

I have a 320i BMW, 2002 model E46. The vehicle is not used much and the last time I used it without the current problem was in January, this year.

About a month ago I tried to start the car after charging the battery (battery was flat) and it just continued swinging. I cleaned the Mass air flow sensor with the correct Mass Air Flow Cleaner and it still did not start.

Then I got underneath and checked the fuel filter by opening one of the pipes. I put it back and tried starting and it started. The following day I drove the car to the shopping centre and got stuck. It was cranking and I would get some engine movement but it will die. Tried a couple of times and eventually it would not start at all, but will crank. I towed the vehicle home (about 4 km away).

The next day I decided to change the fuel filter as I thought that it could be that which is causing the problem. The car started without a hassle.

Last week I drove the vehicle about 110 km and got to my destination ok. About 15 minutes the vehicle will not start and it did the same thing that it did at the shopping centre.

I rested the car and started it the next morning at around 10h00. It started one shot. I started it again at about 13h30 to get back home and boom it started again without a hassle.

I got all the way home which was about 110 km and switched off the vehicle. About 20 minutes later the car will not start and it is still cranking but not starting. I tried the following:

  • Removed, tested and put back the fuel pump relay (5 pin green) - still cranking but no start
  • Removed and cleaned the Mass Air Flow Sensor with Liquimoly Lultmassensensor-reiniger (air flow sensor cleaner) – still no start
  • Checked the fuse number 54 (fuel pump) and it is ok
  • Checked all the fuses under the hood (5 fuses) and they were fine. It is the one that is black and houses the 5 fuses). Indication was that it could have been the middle one that could be blown.
  • People say to me that I must replace the crank or the cam sensor. Now that the car is not even starting my process of fault elimination is very difficult.

Please assist and thanks in advance for your help.

Comments (2)

hmm, the mass airflow could be a fault because I got one for my 2002 X5 3.0i and after a couple of months it started acting up again until I replaced it and it runs great.

No. 1-2


bmws are not DIY cars by any stretch. Without a dealer scan computer and years of experience working on them is foolhardy. And letting one sit unused, really, better to sell it off than treat it that way. They are not made to sit with all those electronics inactive. I can bet you have an electronic failure, but which one, without my scan tool hooked up, it's just crazy guessing wildly at the source.