screech when using full acceleration

"when the revs reach about 4500-5000 I hear a screech from the front, goes away when I pull off the pedal."

A bad crankshaft pulley sounds like a loose belt when the bushing slips. Put a chalk mark across the bushing to see if the haves are slipping. Had 79 245 D, 81 240 D, 86 240 320,000mi and running fine when traded 94 944 Green 257,503 mi CRUNCH Parted out Have 94 944 White 149,000 The New one 94 944 Maroon 135,000 mi

i would guess pully or belt...look for shiney belts.. (i think).....

When making a *left* turn (only) into traffic with pedal to metal, my '98 V70XC has been known to emit an incredible shriek. The friendly Dealer has never been able to replicate the situation, much less suggest a cure. This has recurred over a period of 2-3 years and 40K miles.

I'm convinced it's the transmission or drive line, with the possibility of the viscous coupling objecting to a speed differential front-to-rear. Since a heavy acceleration turn lasts a lot longer on a left turn, the problem has a longer build time. I have wondered if there was a shift in transmission lube level that causes partial loss of pressure to one of the clutch bands or packs. Who knows . . .

bob noble Reno, NV, USA