BMW X5 Starting Problems - 4 mechanic's later HELP!

[neznarf]

Hello all hoping I can find some ideas here as to what may be causing my issue.

I'll try to keep this as concise as possible...

2007 BMW X5 3.0si

Problem:
Car cranks but will not turn over in cool cold or rainy weather. After trying a few times sometimes 1-2, sometimes 9-10, the car will finally start. A couple times I've had it completely not start at all.

What's been inspected (as far as I know):
Fuel pump
Starter
Battery
Fuel pump wiring kit

Issues found and resolved:
2nd mechanic pulled codes for crank and cam sensor, both replaced with original BMW parts.
Last mechanic pulled the dash and found oil filling the computer connector casing. Cleaned that out.

My main issue is that whenever it's at the mechanic they have a tough time finding out exactly what it is because the car will eventually start. Does ANYONE have ANY recommendations/possible solutions?? Thanks so much for any help or advice.

[JL350]

Hi there

Fuel and spark are the key at the right times is the key. Is the engine cranking at the usual speed, could indicate the starter is not getting enough current from the battery, a jump starting pack connected to the battery, or a new battery to see if that makes a difference.

Fuel pressure or supply may be an issue. Just have to test one component at a time. Any chance of dodgy fuel with water in it etc. Drain the fuel tank and put good quality premium fuel in it. Fuel filter been changed? Injectors ok? Getting the right pressure on the fuel rail?

Air flow meter, oxygen sensors, spark plugs, coil packs, crank angle sensors are other things to check.

Did this just start all of a sudden, any modifications beforehand?

Sounds like electrical issue with the cold and rainy weather.

Start with the simple things, battery terminals clean and making good contact, test to make sure the starter motor is getting 12 volts. Check the spark plugs for carbon build up, wetness prior to starting it up.

Another option is to put it on the dyno, they should be able to diagnose air fuel ratios, ignition curves, timing etc. Particularly cold start performance.

Good luck with it all. It will end up being something simple and also the last thing you look at.

[neznarf]

Originally Posted by JL350

Hi there

Fuel and spark are the key at the right times is the key. Is the engine cranking at the usual speed, could indicate the starter is not getting enough current from the battery, a jump starting pack connected to the battery, or a new battery to see if that makes a difference.

Fuel pressure or supply may be an issue. Just have to test one component at a time. Any chance of dodgy fuel with water in it etc. Drain the fuel tank and put good quality premium fuel in it. Fuel filter been changed? Injectors ok? Getting the right pressure on the fuel rail?

Air flow meter, oxygen sensors, spark plugs, coil packs, crank angle sensors are other things to check.

Did this just start all of a sudden, any modifications beforehand?

Sounds like electrical issue with the cold and rainy weather.

Start with the simple things, battery terminals clean and making good contact, test to make sure the starter motor is getting 12 volts. Check the spark plugs for carbon build up, wetness prior to starting it up.

Another option is to put it on the dyno, they should be able to diagnose air fuel ratios, ignition curves, timing etc. Particularly cold start performance.

Good luck with it all. It will end up being something simple and also the last thing you look at.

thanks so much for the help. I will update this post as soon as they figure it out.