Whinning noise when I accelerate fast. 98 s70 glt

skidaddy13 · Post by **skidaddy13** » 11 Jul 2012, 21:44

Would someone explain what this could be? It makes the high pitch noise when really pushing down on the gas pedal and when I let off the gas after it sounds like its letting air out. Any input would be great!

Post by **jblackburn** » 11 Jul 2012, 23:16

Compressor bypass valve? Does it sound like air?

skidaddy13 · Post by **skidaddy13** » 11 Jul 2012, 23:59

jblackburn wrote:Compressor bypass valve? Does it sound like air?

It sounds like air being let out when I let off the gas pedal. When I accelerate the whining gets louder the more I press down on the gas pedal. It sounds like its inside the car and not in the engine. I have not noticed it much before I just happened to be driving with the radio off after finally finding the vacuum leak on my turbo, yes one problem to the next

Post by **jblackburn** » 12 Jul 2012, 06:58

I stick with my answer.

Post by **JimBee** » 12 Jul 2012, 08:42

I'm wondering if it's the same thing I hear when I wind up my '96 855 n/a (135k miles). I would describe it as a sort of metallic ringing that I suspect might be coming from the AC compressor. It gets louder wtih rpm's. I'm sure it's coming from something that goes 'round as the engine turns.
I replaced the TB kit (from Volvo) last summer and that didn't change the sound (though I didn't change the water pump).

hatpmv · Post by **hatpmv** » 12 Jul 2012, 10:41

I am guessing but I did have a similar problem with my s70, and it was a vacuum hose on the air breather box.