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Discussion Starter #1
Well I was at the track having a blast and in the last session the track had dried out, the traction control had been off most of the day and I decided it was time for full power! I made it to the end of the front straight at about 140mph and the car went into failsafe. I restarted the car on the track bumped the HP down and finished the day. This has happened before but it is very intermittent, it only happens coming down the front straight at the Ridge Motorsports park at 500hp when I start braking. I changed the Vanos solenoids but that did not solve the problem.

Just looking for some feedback before I start throwing parts. It is always bank 2, passenger side? It is always exhaust cam. There were actually three events so maybe there is a fault counter that puts the car in failsafe? The passenger side vanos is noisy and I believe there is an upgraded vanos assembly from the 06 that I have. I am an engineer so I really want to know for sure before I replace parts. Due to access, cost and the frequency I am thinking of replacing the cam sensors? If it were a mechanical problem I think it would be more frequent. I have 110k on the motor, FAMS tune, Rod bearings done at 98k. The vanos test with INPA is within limits.
 

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You already have a good solenoid so the next logical step would be changing the position sensor, it’s not a big investment and maybe the reason its happening intermittently is because the sensor is starting to go bad.

If that doesn’t eliminate the problem I would go deeper into the vanos itself. Maybe there is some wear in the unit or the cam gears causing the exhaust cam to get out of timing for a brief moment.




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Nice thing about these engines is you have 2 of everything. Swap sensors between banks first. Unless they are side-specific, but I doubt it...
 

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Discussion Starter #4
That is a good idea. It would be twice the work but I would know for sure if the fault follows the sensor. All four are the same, just watched a video on changing them.
 

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Discussion Starter #5
Well, baby steps. So for starters I started working on the correct side of the engine. Bank 2 is the drivers side. I guess when I was doing the testing and replacement of the vanos solenoids I was just drawn to the noisy side. So I pulled all of the plastic out of the way and just swapped the cam sensors on one side(drivers). I hope it will move from exhaust to intake but I doubt it. Those type of sensors usually are working or not.

Afterward I took the car out and as much as possible I wailed on it. Let me tell you that shift to second at close to 8k rpm with the FAMS tune is just wicked. It just lights the tires right up. I also did my first full commitment launch. Held the pedal to the floor but the car never shifted. 8500 rpm seems a little crazy but I guess that's what it is built for. No engine failsafe. Unfortunately I may have to wait until next year to be back at the ridge doing 140 down the front straight.
 
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