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Discussion Starter · #1 · (Edited)
Hi Guys,

First off - I appreciate that some of the problems here might already have answers, and I have (where possible) tried to look them up.

My 01 M5 has done over 150,000k now. It's also had it's clutch changed in the last few months. MAF's were replaced 2+ years ago.

Yesterday the car drove beautifully, with some slight vibration at idle.

Today, we drove out for lunch - again, no real issues. On the way back, however, the car was really struggling. Lots of vibration at idle, sounded like a diesel engine. When driving, engine would make lots of noise, but produce limited power. This was especially apparent in the 2500-4000rpm range. At one point when shifting from 1st->3rd, the car choked slightly as if it was going to stall, despite having plenty (in excess of 2,5000) of rpm, at an acceptable speed - strange experience. I had to pull the clutch out, rev a bit more and then try again. Even with the clutch out, revving seemed sluggish. On the journey home, I nursed the car back in higher gears, but it was clearly struggling. No check engine lights popped up. I did, however, get a Priority 2 message that popped up, but I don't know what it said (matrix has many, many dead pixels). I say it was a priority 2 because I got one gong whilst driving, and it could be cleared with the button. If I put the car into ignition ii (with seatbelt fastened) the message will remain for 20 seconds, and then disappear.

I checked the oil level, and it was full. All I know from the display is that it is a CHECK message.

The engine noise and loss of power happens occasionally, sometimes even on the same day. Temperature here is usually very humid (at least 80%), with current winter temperature at 20c day/10-15 night, and summer peaking at 40c+. Car is always run on premium fuel.

From doing a little bit of reading on the internet, it seems a lot possibly points to the VANOS. The car was taken to the garage which it usually goes to (non BMW, but can read BMW computer) and they suggested replacing part:
AT ADUSMENT UNIT
CYL, 1 – 4
Part Number 11 36 7 831 486

The car was taken to another, similar garage who disagreed and said that there were no major apparent faults and nothing required replacement. The car was then taken to the official BMW dealer here in Bahrain, and given a full checkup. Similarly, they returned and said there were no issues with the car. The car continued to make the loud engine noise at idle, and so the car went back to BMW a few days later. They kept the car for 3 days, and drove it cold, hot and ran all of their diagnostics, and still insisted the engine and VANOS were operating as normal. They raised the possibility that perhaps cheaper/incorrect oil has been used - but had no evidence to support this . However, this was one of the first culprits the smaller garages suspected, and a full oil change (with correct oil) + new filters was done only 6 weeks prior to BMW check.

It was left with BMW that the car should be dropped off when/if issues become apparent again. My Peake code reader was damaged ages ago, and is pretty unusable. I'm going to order a new one, but shipping one from US/UK will take a while. One mechanic I have known a long time has insisted that this is a VANOS issue, and will come and go depending on the engine + ambient temperature. He said it's possible to reseal the O Rings if I can get the correct kit from abroad, but otherwise it would require a new VANOS to completely remove the issue.

I have attached a picture of the CHECK message, and included a video of the engine on idle. It's vibrating a bit, but it's quite difficult to see in the dark and with mr shakycam. I'm hoping you guys can give me some feedback on the sound it's making, and if it's normal? I might be completely wrong, but I think it doesn't sound right at all.

Engine Video - http://www.youtube.com/watch?v=xKnM3yQ3VWM

Would massively appreciate any advice/guidance. Have a good New Year's everyone!

Faraz
 

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If you have massive power loss suddenly. And have to rev engine clutch down then my guess is mafs. Beacause i have same issues when mafs was about 1.5year old. After changing mafs same thing happened after 20km but never again after maf raplecement. That engine noice is just vanos units...? Maybe you can borrow somebodys mafs to test is the issue there.

edit: Do you have any rattle at startup, i guess that you have. If yes how long?
 

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Like Burnout 187 said, I'd take the mafs out and thoroughly clean them with brake cleaner (soak and use every angle..) and let dry. That won't make them new but can solve your issue for now. MAF:s can be really shot and still not throw codes.

Another usual problem seems to be intermittent bad contacts in vanos solenoids and busted o-rings in the solenoids. Usually if this is the case, the engine will run properly on some rev ranges and poorly on other (either bad idle and high revs or bad mid range in my limited experience). These should leave a code if it causes misfires though.

Both of these solutions are about level 0 DIYs so I'd start with them and go from there. hope you solve it :M5thumbs:
 

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Can hook you up with a good indie workshopin Dubai...


Ifit really the Vanos,shipit to me and you get the units rebuilt back...
 
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