In my experience, the smooth idler roller for the balance shaft is a big source of whining and is really tricky to get adjusted just right. It must be something like between 0 and 0.2 mm away from the belt at rest, but this must be measured from the highest point on a tooth aligned perpendicular to the roller. If it intrudes into the belt line at all, it whines like crazy. The other trick is it kind of has to work together with the sweet spot of the belt tension. Too tight and the belt itself will whine and too loose, and the belt will slap around enough to really rub on the roller and whine. The roller is basicly there to stabilize the belt, and if the belt slaps too much, it whines against the roller. The other tricky thing is it all changes as the engine warms up, but I've had a couple cases of marginal whine that quieted down as the engine warmed up.
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Originally Posted by Slam
Detonation I don't really have ideas about. Have you swapped in a DME without the chip? Do you have vacuum leaks? Maybe the Hall sensor isn't hearing the pinging.
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There is nothing on the NA DME system that can detect pinging. Only on the turbos and the 16 valve motors (S, S2, 968). Is the throttle body and J-boot oily? This would mean a vacuum leak in the crankcase seals somewhere (AOS, dipstick, oil fill cap, rear balance shaft housing seals), that, in addition to being a vacuum leak, usually carries oil mist into the intake, which reduces the effective octane rating of the fuel. Otherwise, maybe it's clogged injectors, weak fuel pump, or some other vacuum leak. The AFM could also be dirty.
http://www.the944.com/afm.htm ...or maybe you left something inside the motor and its rattling around whenever you give it gas.
