Need help please!2009 X5 e70 cranks but won't start

[jukkasm]

It took a while to get access and be accepted into the system - I could not answer earlier.

So it looks that the problem was a bit different. I have e70 3.0si 2008, and a nasty problem.

If I drive 30 miles w the car, and stop. Starts, if tried immediately. After 30mins, tries to start w some cylinders or is rough, runs badly - after 2-4 starting attempts does not even promise to start anymore (all this in cold weather).

If I try to start after cooling off 2 hours - immediately does not start at all (in cold weather). But if I let it sit outside in this same cold weather, the next day starts immediately.

No error codes in Carly, voltage normal in engine bay, new battery (made no difference)

During Summer after this longish drive (say 100 miles) still starts, but only after 2-4 attempts running w partial cylinders/ rough.

Never stops if I get it running, so it is only the start. If it starts it runs.

If I drive short distances, like 1 mile to store and back - no problem. Only when the distance is long enough to overheat something

Drives me crazy. Any ideas?

(Some people hint to module Z11 problems in the discussion forums ab starting problems)

[ard]

There's a blast from the (4 years) in the past....


crazy that there is a hidden timer. and smart to post here when his PMs arent turned on yet!

[jtiffany78]

Ha! Thanks! I really did have to re-read my post...the only thing I remembered from four years ago was the level of frustration..I do miss the X5 but I don't miss fixing it...it was a Carmax car that was a rental...pretty sure it got beat up...the whole analogy about airtime and a skateboard at the XGames applied to this poor car.
I'll get another one someday...and delete it too!!

Originally Posted by ard

There's a blast from the (4 years) in the past....


crazy that there is a hidden timer. and smart to post here when his PMs arent turned on yet!

[jtiffany78]

Wow! That sounds bizarre and very frustrating, I'm sorry to hear you have to deal with this.
I have one question...when did this start? Was is right after it got tuned? Right after a battery swap? or did it start randomly some cold winter day?

I have no solid advice as I've never heard of anything like that but here's a couple guesses that I'm sure your stealerships tried but just in case....

Mechanically speaking, there could be something wrong with fuel delivery and when things (fuel, injectors, cylinders etc) cool off at different rates after heating up..or something is causing the fuel to overheat or freeze...I'm really reaching with the fuel temp but if it's extreme enough I could see it effecting detonation in the cylinder.
I'd be curious to know what kind of fuel pressure is present to each injector when it's trying to start (on the unsuccessful attempts) and cylinder temps when you shut it off after a long drive.
Is your oil just oil? and coolant just coolant? Maybe a crack somewhere causing said cylinders to overheat that needs to cool down significantly before it can fire/start properly. Then again, I imagine you would have trouble with it while it was running if that were the case..I'm thinking out loud a little.

Something electronic seems much more likely...I'm unfamiliar with the Z11 module but after doing a search that certainly seems to be a possibility...looks like they're 100 USD, so 83~ish euro. In BMW terms that's cheap IMO, I'd be willing to throw some parts at it for that price...or push it off a cliff..If I'd have lived near one, that would've been my solution. lol. I also saw that bad voltage regulators or alternators can cause some crazy electrical glitches. Especially the alternator when the battery isn't getting a proper charge, combined with cold cranking could cause some crazy electrical issues.

My other thought is seeing if whoever tuned your ECU would try a reflash...after the glitch that held on in my ECU, I personally would not rule it out.

I wish I could help you more instead of throwing some wild ideas at you but it's all I got based on your description. Feel free to add anything else that's been tried, any other symptoms/clues and I'll continue to help as best I can. With any luck someone much smarter than me will chime in with a miracle fix lol

Good luck....

[jukkasm]

Thanks for the comments.

The car is not modified, so standard ECU.

I was trying to get Carly look for the fuel pressure value, but I did not find that parameter in it.

Very strange.

Jukka

[V12noise]

Carly is an over-rated, over-priced product. I have it... I tried looking up fuel pressure and it isn't there. I have Bimmer Tool too. Much cheaper and it has both FuelPressure setpoint and measured fuel-pressure.