HELP- M54 Motor not firing, Vanos advice

AussieAlan · #1 03-31-2012, 10:06 PM

Sorry for starting another thread on my X5 3.0i not starting issue, I think I have narrowed down my starting problem to the timing after replacing the oil filter housing. I have pulled out the new spark plugs and there is a smell of fuel on them and the electrodes has carbon on them, so there must be fuel & spark getting to the chambers, how much of each is an unknown. That leaves the timing or the ecu. Does anyone know if the vanos unit is not working due to worn seals or no oil feed, can the timing go out to the point of the motor not firing at all. Thanks

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Giznaz · #2 03-31-2012, 10:22 PM

Unless the VANOS was disturbed, unlikely to be the problem. VANOS only affects the mid-range of the rpm range. Car would still run just fine if VANOS didn't work at all.

However, that being said, if the VANOS was disturbed, or the timing chains or sprockets changed, the valve train could be out of time, thus won't start.
IF this were the case, as well, I think the valve train could be damaged, or the pistons damaged. I'm fairly sure the M-54 is an interference motor

amacman · #3 04-01-2012, 01:10 AM

Best have a diagnostic fault code reader check for faults as it could be a faulty sensor or any one of a multitude of electrical components .

Bulk · #4 04-01-2012, 02:04 AM

What Giznaz said..... Mate there is no possible way that you've changed the timing unless you have disturbed the timing chains and if you have done that then we're into a whole nother level.

Good luck mate

AussieAlan · #5 04-01-2012, 02:50 AM

Thanks for your knowledge Giznaz, that's a relief it's not the vanos. I didn't touch them, only removed the oil supply line. i've had the plugs out and nothing has hit them so safe there. So I can discount that, I'll take your advise Amacman & tow it to the dealer to have it scanned, I would say the ecu needs clearing as I disconnected the battery for a couple of weeks. There's no way I can clear it with the ignition & check control? Thank-you all again for your help, I'll let you know the outcome, it will be simply you can bet.

Bulk · #6 04-01-2012, 03:12 AM

Happy to help - Sucks when you do the maintenance yourself and it doesn't end up the way you had planned. I'm not sure that it is a symptom of having the battery disconnected for an extended period though as many guys in the USA have their X purely as a winter snow mobile so leave it in the garage for months with the battery disconnected. Hopefully it gets rectified soon enough for you without the dealer taking last months pay check.

AussieAlan · #7 04-05-2012, 07:27 AM

Thank-you everyone for your help. Just got the X5 back from the dealer and happy it was not anything major. They said Ignition, Airflow & Fuel pressure was fine, but the compression was low. They squirted oil in the cylinders and bingo it fired, they put it down to "stuck piston rings". I still think it had something to do with oil not getting to the vanos unit after I disconnected & reconnected the oil feed line, somehow putting the valve timing out enough to loose compression. Hope this might help someone in the future.

Bulk · #8 04-05-2012, 07:43 AM

You were right all along....

AussieAlan · #9 04-05-2012, 08:07 AM

Hi Andrew, who knows I think it's still a mystery. I think everyone along the line cranked it enough it finally either got enough oil to the vanos or buy oiling the cylinders got enough compression to reset itself. I just glad it's running, had great pleasure in driving it home. Have a great Easter break.

AussieAlan · #10 04-06-2012, 07:41 AM

Updating my problem with restarting a M54 motor after it had been sitting for a month and the dealer couldn't find a fault and put it down to "sticking piston rings" I found this on another forum for E46's which gives the answer, so it did have nothing to do with the vanos unit. Hope this helps someone in the future

"BMW e46 sits for 2 or more weeks and won't start with no fault codes. This is a well known problem to them. Why ? With age & miles: something or things are not operating in spec anymore so the engine doesn't start the first time, the start up sequence dumps a bunch of fuel into the cylinders each time you crank, which washes the oil off the compression rings so you then have very low compression - not enough to start the engine.

How to fix it - if the engine doesn't start the first time, put the accelerator to the floor and crank the engine, it will generally start. In my case I had to take the plugs out, put a 1/2 teaspoon of oil (one squirt from an oil can) into each cylinder (get a long skinny hose ...) turn over the engine a few times, put the plugs in, and the engine starts immediately, once the smoke clears, it runs fine"

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