Rough idle on 545i, dealership hasn't helped. Please help!
#21
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Hey,
What do you mean by oil in the intake how much, did you inspect it?
Actually I took off the throtle body and it was rather dirty on the inner side of the butterfly valve. There was also some oil on it.
I cleaned it and put it back and after around 1k miles i checked it again and there was again a thin layer of oil-dirt on it.
My mechanic friend drives a 745i roguly the same milage. His throttle body was also dirty and a bit oily.
I asked him about the issue and he told me that in some operating conditions, the exhaust and intake valve are both slightly opened.
So intake valve already opens before exhaust valve has fully closed. This causes the dirt and oil in the intake.
blackonblack
Maybe you could take of the throttle body, clean it, drive 1k m and make a picture of the inside part of the butterfly, than i could compare it to mine.
What do you mean by oil in the intake how much, did you inspect it?
Actually I took off the throtle body and it was rather dirty on the inner side of the butterfly valve. There was also some oil on it.
I cleaned it and put it back and after around 1k miles i checked it again and there was again a thin layer of oil-dirt on it.
My mechanic friend drives a 745i roguly the same milage. His throttle body was also dirty and a bit oily.
I asked him about the issue and he told me that in some operating conditions, the exhaust and intake valve are both slightly opened.
So intake valve already opens before exhaust valve has fully closed. This causes the dirt and oil in the intake.
blackonblack
Maybe you could take of the throttle body, clean it, drive 1k m and make a picture of the inside part of the butterfly, than i could compare it to mine.
#22
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My Ride: Orient blue '05 545i, Sport/Premium Pkg, 6Speed MT, Xenon, Navi, Blue2th, PDC,
Differential pressure sensor 1 13627585278
http://realoem.com/bmw/showparts.do?...77&hg=11&fg=40
Not sure why the price is not listed.
#23
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Hey,
What do you mean by oil in the intake how much, did you inspect it?
Actually I took off the throtle body and it was rather dirty on the inner side of the butterfly valve. There was also some oil on it.
I cleaned it and put it back and after around 1k miles i checked it again and there was again a thin layer of oil-dirt on it.
My mechanic friend drives a 745i roguly the same milage. His throttle body was also dirty and a bit oily.
I asked him about the issue and he told me that in some operating conditions, the exhaust and intake valve are both slightly opened.
So intake valve already opens before exhaust valve has fully closed. This causes the dirt and oil in the intake.
blackonblack
Maybe you could take of the throttle body, clean it, drive 1k m and make a picture of the inside part of the butterfly, than i could compare it to mine.
What do you mean by oil in the intake how much, did you inspect it?
Actually I took off the throtle body and it was rather dirty on the inner side of the butterfly valve. There was also some oil on it.
I cleaned it and put it back and after around 1k miles i checked it again and there was again a thin layer of oil-dirt on it.
My mechanic friend drives a 745i roguly the same milage. His throttle body was also dirty and a bit oily.
I asked him about the issue and he told me that in some operating conditions, the exhaust and intake valve are both slightly opened.
So intake valve already opens before exhaust valve has fully closed. This causes the dirt and oil in the intake.
blackonblack
Maybe you could take of the throttle body, clean it, drive 1k m and make a picture of the inside part of the butterfly, than i could compare it to mine.
#24
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My Ride: 2008 535i | Black Sapphire | Black Nasca Leather | Sport Package | Heads Up Display | Navigation | Lane Departure Warning | Electric Rear Sunshade | Logic 7 Sound System | USB audio | Heated Rear Seats | Ventilated Seats |
Picked up: February 25, 2008
I'm no expert but I had rough idles on my 535i and it was the HPFP to be blamed. Could that be the case?
#26
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My Ride: Orient blue '05 545i, Sport/Premium Pkg, 6Speed MT, Xenon, Navi, Blue2th, PDC,
I still think that they are OK. First the oil leak problem needs to be resolved.
I would start with the pressure sensor.
#27
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Not sure how oil can get stuck in convertor, as flashpoint of oil is about 1000 degrees lower than operating temp of convertor.
1. If convertor was seriously clogged, you would lose power while driving car. ( Max speed would significantly drop off.)
2. Identify and write down error codes.
3. Have you check Mass air flow sensor (or BMW's equivalent)?
4. Check for cracked vacuum line. Normally a vacuum line will make the miss occur consistently. It could be a vacuum line that is vibrating a small crack in it. (BTW, not very likely, but....)
5. If miss gets worse under load (a/c and accelerating up hills), check coils.
6. Do you see or hear any spark jumping/grounding from ignition at night?
1. If convertor was seriously clogged, you would lose power while driving car. ( Max speed would significantly drop off.)
2. Identify and write down error codes.
3. Have you check Mass air flow sensor (or BMW's equivalent)?
4. Check for cracked vacuum line. Normally a vacuum line will make the miss occur consistently. It could be a vacuum line that is vibrating a small crack in it. (BTW, not very likely, but....)
5. If miss gets worse under load (a/c and accelerating up hills), check coils.
6. Do you see or hear any spark jumping/grounding from ignition at night?
#29
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I cleaned the MAF sensor and the throttle body, now the RPM fluctuates a little bit less, but it idles a lot higher. It is currently idling at around 1,200 RPM.
#30
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My Ride: 2006 BMW 550i
the engine computer should readjust the idle automaticaly as you run the car.