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      04-11-2013, 06:29 PM   #46
TVMA Doc
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Drives: 2011 E90 M3, Jerez Black
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Quote:
Originally Posted by Mike Benvo View Post
Hey guys, sorry for the lack of description... to fill you in on some details

-The car was located in Australia.
-The owner of the car just purchased it a few weeks ago
-The dealer that sold it to him gave it to him with a water damaged amp
-Apparently there they can get away with this kind of stuff without recourse like we have here

Now - onto the freezeframe data.

I definitely believe that the motor saw 9985 RPM, and I think something broke there by looking at the reference signal @ vanos. A few other things to note:

-When this event happened, airflow was calculated to be 4kg/h. That's basically like no airflow at all. At 8,300 RPM, these cars are seeing about 1200kg/h based of the MAP sensor calculation.
-My car has seen a max of ~1300kg/h at high RPM.
-You'll also notice that at this moment this data was recorded, the pedal position was 0%, meaning the engine must have been completely off.
-The RPM gradient was negative, indicating that there was serious deceleration when this event occurred.
-The transmission speed at output shaft during this this event indicates 0 RPM.

The car had about 50,000km when I read this data, so it seems as if the engine or whatever was broken had been replaced prior to the resale of the car.

Now - this would all make sense on a manual car. Given this car has only reached redline fifteen times according to this data, it doesn't seem like a car that was flogged around. Oil and coolant temperatures were warm and in safe areas at the time of this event.

But... This car was DCT. So I can not for the life of me understand how this happened. The RPM is controlled pretty much exclusively by the DME, so the only thing I can think of is some sort of accidental misshift by the DCT transmission (which the likelihood of that is extremely small).

If it was a US car I would be able to see the warranty history on it, but unfortunately I can't see that information on non US Spec vehicles.

Regardless, the car is running well now. And since the owner's amp is dead, all he gets to hear is that lovely V8 sound.

I wish it added up, but it doesn't.
I have an employee with a 2006 M5 with SMG. She was driving along at 40mph when the ECU just decided to shift into reverse. I've heard about issues with the SMG, but this is the first I've heard about with the DCT. I hope that it was just a random gremlin in the machine rather than a more common glitch.
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