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engine problem,not sure.2006 bmw 645ci

6K views 18 replies 8 participants last post by  HerbP 
#1 ·
2005 BMW 645ci

Where do i start??? i am having BIG BIG problems with my baby
HELP!!!!

bought some bad gas "low grade" and ever since then my car has been rough / erratic idling. i called a friend of mine who used to be a bmw tech, he advised me to drop my tank, dump the gas, clean the injectors and put virgin fuel back into my tank.

i have since done that, how ever, my car is still backfiring. even without starting my car, when i turn the ignition to the 2nd position i hear a clacking sound coming from the throttle body. i have reason to believe that once i eliminate that sound my car will stop backfiring.

has anyone else had this problem? pls help!!!!
 

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#3 ·
2005 bmw 645ci

Where do i start??? i am having BIG BIG problems with my baby
HELP!!!!

bought some bad gas "low grade" and ever since then my car has been rough / erratic idling. i called a friend of mine who used to be a bmw tech, he advised me to drop my tank, dump the gas, clean the injectors and put virgin fuel back into my tank.

i have since done that, how ever, my car is still backfiring. even without starting my car, when i turn the ignition to the 2nd position i hear a clacking sound coming from the throttle body. i have reason to believe that once i eliminate that sound my car will stop backfiring.

has anyone else had this problem? pls help!!!!
 
#4 ·
2005 bmw 645ci issues

Where do i start??? i am having BIG BIG problems with my baby
HELP!!!!

bought some bad gas "low grade" and ever since then my car has been rough / erratic idling. i called a friend of mine who used to be a bmw tech, he advised me to drop my tank, dump the gas, clean the injectors and put virgin fuel back into my tank.

i have since done that, how ever, my car is still backfiring. even without starting my car, when i turn the ignition to the 2nd position i hear a clacking sound coming from the throttle body. i have reason to believe that once i eliminate that sound my car will stop backfiring.

has anyone else had this problem? pls help!!!!
 
#6 ·
pls help

bought some bad gas "low grade" and ever since then my car has been rough / erratic idling. i called a friend of mine who used to be a bmw tech, he advised me to drop my tank, dump the gas, clean the injectors and put virgin fuel back into my tank.

i have since done that, how ever, my car is still backfiring. even without starting my car, when i turn the ignition to the 2nd position i hear a clacking sound coming from the throttle body. i have reason to believe that once i eliminate that sound my car will stop backfiring.

has anyone else had this problem? pls help!!!!
 
#7 ·
what should i look for?

Where do i start??? i am having BIG BIG problems with my baby
HELP!!!!

bought some bad gas "low grade" and ever since then my car has been rough / erratic idling. i called a friend of mine who used to be a bmw tech, he advised me to drop my tank, dump the gas, clean the injectors and put virgin fuel back into my tank.

i have since done that, how ever, my car is still backfiring. even without starting my car, when i turn the ignition to the 2nd position i hear a clacking sound coming from the throttle body. i have reason to believe that once i eliminate that sound my car will stop backfiring.

has anyone else had this problem? pls help!!!!
 
#10 ·
I second Herb's suggestions.

I would do the easy things first. Check the fuel pump and replace the fuel filter. Next I would send the injectors out for a proper cleaning and get them flow balanced while you are at it. There are injector cleaning and blueprinting specialists out there that will make the injectors perform better than new.

I don't think bad gas would cause any problems with the throttle body. You may have an issue with the throttle body but that would be a peculiar coincidence.
 
#11 ·
i am in a process of checking my fuel filter and fuel pump like some of you have suggested. how ever, this morning i noticed that there is some oil in my throttle body. i don't know where this oil leakage is coming from. that cant be normal, is it?

n/b as far as the 3 post..sorry, it was not intentional...it was an error on my part.
 
#12 ·
Thats really weird that you would have back firing and no check engine lights! These cars are so sensitive that if you fart in the wrong position in your chair the check engine will light up.
Oil in the throttle body is very weird as well. Are you sure it's oil and if so how much? I think the best thing to do is have a friend put the ignition in the second position while you pay close attention to the engine and see where that clanking noise is coming from.
 
#13 · (Edited)
Hi! It is very hard to buy truly bad gas in the UK, even the most obscure petrol sellers or at worst supermarkets don't sell petrol that would cause this kind of issue???? This includes the lowest level of octane available to buy as it all must conform to a set standard to be sold in the UK. If that bad go to trading standards and seek redress!!!!
However I would ask given some of the symptoms, did someone inadvertently put some diesel in ( you would be surprised how common this is), which would account for some oily deposits in the throttle body......If this is the case subject to how much was dumped in you may get away with a complete fuel system clean and a flush of the tank, if you have been running the car and it is well into the engine then !!!!!!!!!!
 
#14 · (Edited)
The only thing of that could make a clacking noise while the key is in the 2nd position would be the ValveTronic motor try to calibrate itself. There are 2 motors under the engine cover, one on each side. If the noise is coming from either one, you have valve train problems. This could cause the motor to backfire! You probably need to get the car to a proper mechanic, before any more damage is done.

Good Luck!
 
#15 · (Edited)
i live in the UK or from the UK but work between UK and the STATES.....but now with NIGERIA

the car was bought in the STATES where i drove it for a year....i brought my car to NIGERIA, AFRICa. its been here only 2months.....its in NIGERIA i got the fuel.
plus i had the car worked on before it was shipped to nigeria
 
#16 · (Edited)
Hi! Now I understand about the quality of petrol!!!!! I think what others have mentioned give the fuel system a good flush, maybe consider as mentioned changing the fuel filter. If possible give the car a very long run as short runs will not get the engine, catalytic converters up to temperature were they burn off all of the impurities. Remember it takes a good 35-45 mins of driving for these temperatures to be reached!!!!!! You may want to check the air intake and MAF in case you have a dust issue?????
Have to say your very brave to take a 6 series to Nigeria, I think i would have left it somewhere garaged and used something else in country! But I suppose because it is left hand drive you wanted to get as much out of the car as possible!!!!!!
 
#17 ·
i am still having a very odd idle fluctuation problem.
when i start my car, it revs up and down by itself in a very inconsistent pattern.
when i run a diagnosis on it, it gives me 2 faults
1 - throttle body actuator and
2 - DME internal fault
can someone tell me what to do?
 
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