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Discussion Starter #1 (Edited)
Gang;

More than occasionally & regardless of gear, the car pulls as expected to a point ( 3-4K rpm ) then feels like it's missing 2 cylinders - as if the timing has been retarded.
Attempting it in first, I'll get the tire squeal, a NICE launch followed by flat on it's face power loss as the revs rise. It's so violent in first that both the passenger & I lunge forward (!).

MAF or cam sensors?
As an FYI, I peered inside the air intakes - near the MAFs - all looks clean & dry. Nothing but O2 sensor has been performed under warranty as well on this 32,000 mile beaut.

All guesses are appreciated… mmmmmm
 

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vics said:
Gang;

More than occasionally & regardless of gear, the car pulls as expected to a point ( 3-4K rpm ) then feels like it's missing 2 cylinders - as if the timing has been retarded.
Attempting it in first, I'll get the tire squeal, a NICE launch followed by flat on it's face power loss as the revs rise. It's so violent in first that both the passenger & I lunge forward (!).

MAF or cam sensors?
As an FYI, I peered inside the air intakes - near the MAFs - all looks clean & dry. Nothing but O2 sensor has been performed under warranty as well on this 32,000 mile beaut.

All guesses are appreciated… mmmmmm
Well I guess I have a 50/50 shot, :) , but I would guess MAF. If it was the CPS, I would expect more constant performance (or lack of it). If the CPS is not working, then the variable cam timing is not working, so the car feels sluggish to different degrees across the rpm range. If you can get launch hard enough to pin you back, then it sounds more intermittant, which is the way a bad MAF will behave.
Regards,
Jerry
Regards,
Jerry
 

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These symptoms (misfire then running in default limp-home-mode) have been detailed on the boards here numerous times, and the remedies vary quite a bit.. basically, it could be anything from cam sensors, to lambda probes, to complete vanos units, to coils, to air mass meters to spark-plugs etc.. and the ecu fault memory returns pretty much all of these errors, as one can trigger another, for instance a faulty cam sensor could alter timing sufficiently to produce a misfire returning false oxygen sensor readings etc..

My 2000 M5 was (and still is) misfiring sporadically, usually while under full load in 2nd gear.. and was improved remarkably following a change of (very black) spark-plugs, so the latest prognosis is that a vanos oil seal may be leaking out into the plenum area, and down into the combustion chamber creating a film of oil over the spark-plugs provoking this misfire, and also resulting in excessive oil consumption. I'm going to have this replaced shortly, but wont be holding my breath.

I've had a 528i jump a tooth on the timing chain (worn crankshaft sprocket coupled with dodgy pretensioner) and this feels and sounds exactly the same, only it took more than a simple ECU reboot \ twist of the ignition key at 60mph to sort that one out..
 
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