Sudden stop and restart to engine

[La_vida_diver]

When I was at Cadwell Park on three occasions I got a sudden and unexplained stutter from the engine. By that what I mean the engine did a full stop and the started again all on it's own when I was at speed in high revs. After Cadwell I noticed the same thing about three times and also at traffic lights on two occasions the engine just stopped while I was in neutral writing for the lights to change. I called in my friendly auto electrician and he found that there were two errors one was the crankshaft sensor imtermittent and the other was that the vanos was physically jammed. He said that he would be surprised at the latter and said change the crankcase sensor and see if it cleared both. The parts from BMW were £89 for the sensor £37 from GSF but for both I had to buy an adaptor wiring loom from BMW which was about £16. Apparently on the earlier 2.8 there was a better way to wire up the system with the vanos so when I changed the crankcase sensor with the new wiring loom the problems went away. I have now done over 2000 miles without a single blip

Edit February 2013

I have now done a number of trackdays and many miles and the problem has not resurfaced also the Electronics have shown no errors since so that was a definite fix.


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[Aceman]

I had the exact same symptons on my 2.8 when I had it which cleared when I changed the camshaft sensors. It's quite unerving isn't it when you are giving it some beans and the engine just momentarily dies then comes back on and I suspect certainly not pleasent when on track. It is quite a common fault on the 2.8 and I did a writeup on how to change them which is in the knowledgebase and wiki if you fancy a read but I didn't have to change the wiring loom when I did mine unless that was on earlier 2.8's.

Edit: just realised you said crankshaft sensor rather than camshaft which is different to my experience.

 

[La_vida_diver]

I had the exact same symptons on my 2.8 when I had it which cleared when I changed the camshaft sensors. It's quite unerving isn't it when you are giving it some beans and the engine just momentarily dies then comes back on and I suspect certainly not pleasent when on track. It is quite a common fault on the 2.8 and I did a writeup on how to change them which is in the knowledgebase and wiki if you fancy a read but I didn't have to change the wiring loom when I did mine unless that was on earlier 2.8's.

Edit: just realised you said crankshaft sensor rather than camshaft which is different to my experience.

Yes I think that was why the loom had what BMW call the adapter cable but we checked out the pinouts of the cable and it changed the way the cables were routed so instead of going back to the electronics and then back out to the Vanos solenoid it went direct and then back. so the wiring was actually changed as well as the part came without the flying lead.

Black is the M52B engine but I also I checked Blue which is the M52TUB and it had the wiring doing exactly the same as the modified earlier engine and the same part as the crankcase sensor. so it was obviously a change that they made in the changeover. Black is July 1998 and Blue is March 1999. so they straddle the September 1998 changeover.