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Discussion Starter #1
...week and the M5 is not going as it should. The problem occured yesterday for the first time. It was a hot day and the car was trembling and shaking when I started it.
It felt as it was not igniting on all cylinders. I started to push it, the car went fine but after a while it entered limp home mode. I had to stop the car and restart it. I have allready cleaned the MAFs, but no result other then that it is going good until it enters limp home mode. So I suspect the ignition coils. What do you think? Lambdasond? Camshaft sensor? Solenoid?
Has anybode else experienced this before?
Please reply asap, since I am planning on traveling with the car next week to southern europe and I need to fix this.

Every suggestion is thankfull and appreciated
 

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Don´t panic!

1. Perform the MAF (fuel-flow) test yourself.

2. Go to a BMW dealer and check for fault codes.

3. Check fuel pressure.

4. If this is a misfire problem, the fault codes will pinpoint which cylinder. Once you know that, swap ignition coils between that cylinder and another cylinder and check if the fault follows that ignition coil. If so replace coil.

If the fault does not follow the coil, then swap or replace spark-plug.

5. Check alignment of the crankshaft sensor (CPS).

6. If there still are troubles, unless the car already has the redesigned camshaft sensors, replace two of the camshaft sensors.

David
 

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IceGBG,

does the car always enter limp-home when you rev it?
Just when you rev it during a WOT acceleration?

David
 

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Discussion Starter #5
More or less when I rev it hard, then it enters limphome mode and the whole car starts to shake and shiver, like it´s only igniting on 4-5 cylinders.
 

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If you give just a little throttle while accelerating in 1st gear, does the engine still cut out?

David
 

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Discussion Starter #7
Nope, not at once, but after a while, it enters limp home or some sort of emergency mode, because the engine vibrates when I give some throttle.
 

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Discussion Starter #8
The car is at the dealer now and they have run a diagnostic check.
The first thing the machanic said was that the right hand side MAF is bad, we have to replace it. The engine is misfiring on cylinders 5,6,7 and 8.
Then I told them to replace it and it still missfired.
Then the diagnostic read out said it was one of the solenoids (magnetic valves) for the Vanos. Now he they have ordered a solenoid in order to replace it.
This will set me back for 1300 dollars appr.

Does this seem as a possible explanation to you, guys?
Have anybode else here on this forume exchanged the solenoid for the vanos?
 

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Many have needed to replace MAFs and Vanos valve solenoids.

How many miles on your car?
If you are over 60000 km / 40000 miles you might just as well replace the other MAF too.

(The left and right solenoid units for the Vanos´ are the exact same. To verify the diagnosis, you can swap the solenoid units between the left and right Vanos unit. If the fault follows this swap, then you can be fairly certain the solenoids are actually bad.)

David
 

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IceGBG said:
Then the diagnostic read out said it was one of the solenoids (magnetic valves) for the Vanos. Now he they have ordered a solenoid in order to replace it.
This will set me back for 1300 dollars appr.

Does this seem as a possible explanation to you, guys?
Have anybode else here on this forume exchanged the solenoid for the vanos?
I thought the solenoid valve can be changed out without doing the entire Vanos unit, which should be much cheaper. I didn't remember that solenoid valve being that expensive. You might do a search here for that, it was a recent thread, or at least a thread that was recently updated with this discussion.
Regards,
Jerry
 

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IceGBG said:
The car is at the dealer now and they have run a diagnostic check.
The first thing the machanic said was that the right hand side MAF is bad, we have to replace it. The engine is misfiring on cylinders 5,6,7 and 8.
Then I told them to replace it and it still missfired.
1. In what direction of the car did you face when you defined what is left and right?
In the direction the car travels, cylinder bank 2 (cylinders 5-8) is on the left-hand side of the car. (and your post said you replaced the right-hand side MAF... maybe that is the reason it still misfires). On the other hand, the signals from both MAFs are summed and used to control the fuel-injection for both cylinder banks, so it should not matter at all.

2. After the MAF has been replaced you need to drive the engine at more than half throttle and above 3k RPM for a certain accumulated time before the fuel injection adaptation is fully correct.

3. With misfire on all cylinder of one bank, I would guess at either a camshaft sensor or the Valves.

I hope it works out!

David
 

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Discussion Starter #13
The right hand side when sitting in the vehicle.
But the mechanic said the the right MAF was for the left cylinder bank and also the solenoid of the left cyl bank was faulty according to then diagnosis system.
 

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