Check the two idler pulley bearings on the "vee" belt going to the A/C compressor. You can actually remove the belt and run the motor. If the noise goes away turn the pulleys by hand. They should turn smoothly with no noise. The bearings in the pulleys can be replaced. Another more expensive possability is the water pump. The bearings in it can go bad and that will require replacement of the water pump. Exhaust noises usually don't come and go, they just get worse slowly. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, Jan van de Wouw <jvdwouw@xxxx> wrote: > Hi, > > While driving this afternoon all of a sudden I heard a strange > noise from the back, it sounded like a sort of "shrieky whistle" > and increased with giving more throttle. > > First thing that came to mind was the blowoff from the cooling, > caused by a blown head gasket, so I stopped immediately... > My coolant was still in the system, under pressure and the > blowoff hose was dry. My oillevel was still right and there > was no foam evident on the oil... > I guess I can rule out the headgasket... > The temp on the Gauge was on the "7:30"position, where it's been > all day (runnning the A/C and driving no faster than 50mph... > -----------------