HELP!! Engine suddenly dies, restart all ok???

[seech]

Guys. Need some help. Lately on two occasions my E34 M50B20 engine suddenly died. After restarting all ok. Very hard to diagnose problem.The first time the engine suddenly lost power and would not rev above idling and then after about 10 secs engine died. Turned ignition off and restarted and everything ok.The second time while trying to exit a junction, engine died again without warning. Luckily haven't exited junction yet. Restarted and everything ok.Lately, I also noticed that now when I start my car the dashboard 'resets' itself. Last time when I turn on the ignition the check lights come on and then go off just once. Now when I start the car the dashboard 'resets', check lights come on again and then go off for the 2nd time. Dunno if this is related to the problems of the engine dying.Fuel economy also seems to be quite bad for the last two tanks.Work recently done:Cleaned MAF and Intake Temp Sensor (few months ago. some improvement)Changed ignition coil boots (huge improvement)Ran with V-Power for a couple of tanks.Changed alternator 2 weeks ago (checked the voltage and it appears to be ok)Anyone experienced this before? Any ideas?Dunno what to do now. Always tension the car is going to break down especially with the family inside. Appreciate any help or comments.Thanks.

 

[jarance]

check your fuel pump and fuel filter..

The pump is about to kaput...

 

[seech]

jarance, thanks for the feedback. just changed the pump about 1 year ago but i did notice its a bit noisy. fuel filter never changed before. i'll do that asap and see if it helps. many thanks.

 

[flash]

How long ago was the battery changed?

I had intermittent problems like that before... dashboard cuckoo, engine losing power and cutting out, etc. One day, the engine completely lost power, could not restart, no lights...checked, battery problem. It had shorted out. Changed the battery, back to normal.

 

[affan66]

could be crankshaft timing sensor.

 

[jarance]

could be crankshaft timing sensor.

Yes can be also..

Once have a crankshaft problem.. can die off but can restart.. After 2 times, it never restart again until the sensor is replaced.

 

[seech]

Guys, thanks for all the feedback.

Changed the fuel filter yesterday. The filter was damn dirty. Will see how that goes.

I think it might be the fuel pump again. Yesterday night tried to start and car was cranking but could not start. Off and on the ignition and then all ok.

This type of mysterious disease is the worst one.... so many possible faults. AFM, Crankshaft Timing Sensor, Coils, Fuel Pump.....

 

[bluepanther]

could be crankshaft timing sensor.

Hi seech, im having m50b20 and your problem reminds me of what ive encounterd 2 years ago. Exactly the same except trhe dashboard lights resets. At the end the car gave a strong crank BUT it just won't start.
After diagnosis it says "crankshaft sensor". Changed the item and im a happy man from that day on.

 

[X5madani]

Guys, thanks for all the feedback.

Changed the fuel filter yesterday. The filter was damn dirty. Will see how that goes.

I think it might be the fuel pump again. Yesterday night tried to start and car was cranking but could not start. Off and on the ignition and then all ok.

This type of mysterious disease is the worst one.... so many possible faults. AFM, Crankshaft Timing Sensor, Coils, Fuel Pump.....

After all the efforts, why not u bring your car to a reliable workshop. Check the Control Unit, this is the most expensive part that u might need to change.. the heart of the electrical/electronic system.

Dont change anything yet. Try to borrow from any friends driving exactly the same model/specs; exchange and fix the control unit temporarily, test drive and you compare at low and high speed, exit junctions, approach corners and make an emergency brake. Feel the differences.

If u happy with the "replacement", then shop around. I had experience the same on my C220 6yrs ago and cost me around RM5.7K. You check the price at shop.eBay.com.

 

[seech]

hi guys, will be taking the car in for a diagnostics check to find out what the issue is. Left the car for a few days over CNY. When restarted it seemed like 1 cylinder not firing but after warm up ok.... -sigh- so many problems......

 

[beemer04]

I had the same prob on my e36, it was the timing sensor, get vasu (BMWorks) to check for u!

 

[seech]

beemer04, how did he diagnose it was the timing sensor? Diagnostic check or he suspected and changed the part? Can PM me BMWorks details? Might want to drop by for him to take a look. Many thanks.

 

[beemer04]

There were trial and error and I had to revisit the mechanic several times before he diagnose it as timing sensor via the modic on the last visit, cost me ard RM400 for the sensor if not mistaken.

 

[seech]

Finally sent my car in to get a diagnostic check. Many thanks to Vincent Hor for recommending Albert of WP Auto. Diagnostics indicated possible fault with Air Mass Meter and also #1 Injector. After clearing faults they did not come up again so Albert advised driving the car first to see if the faults reoccur. Will see how it goes.

Strangely enough car feels smoother and less sluggish but I might still be suffering from CNY hangover so dunno if I'm imagining things.

Many thanks Vincent! Cheers...

 

[Vincent Hor]

You are welcome.

Finally sent my car in to get a diagnostic check. Many thanks to Vincent Hor for recommending Albert of WP Auto. Diagnostics indicated possible fault with Air Mass Meter and also #1 Injector. After clearing faults they did not come up again so Albert advised driving the car first to see if the faults reoccur. Will see how it goes.

Strangely enough car feels smoother and less sluggish but I might still be suffering from CNY hangover so dunno if I'm imagining things.

Many thanks Vincent! Cheers...

 

[bluepanther]

....hope your nightmare ends.