screech when using full acceleration

When I floor the pedal, the car takes off as expected, but when the revs
reach about 4500-5000 I hear a screech from the front, goes away when I pull
off the pedal. The car is a 745 2.0 with an AW70 gearbox. It sounds like a
belt under load eg the alternator belt when the electrics are loaded and the
belt is loose, but only happens under full acceleration at 4500 and above
revs. Could it be the auto gearbox making this noise? anyone have an idea
about this? The noise sounds like its from the front of the car, but it's
hard to tell under max acceleration. It's definately not from the back.

 

"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

 

loose belts shiny belts wife screaming any or all of the above