Whining/whirring noise after shutting off engine (1996 850)

mc510 · Post by **mc510** » 28 Nov 2010, 21:30

When I shut off the engine today on my 1996 850 wagon (base model, NOT turbo, 180,000 miles) I heard a whirring/whining noise from the engine compartment; it slowed down to a stop over about 5 seconds, with the noise getting quieter and lower in pitch. The best comparison I can think of is the sound of a turbine engine winding down to a stop. I've heard this noise from time to time over a couple of years, but it is not always present. Today it was unusually loud. I should mention that when I was driving, I thought I was noticing a new (different and hard to describe) noise when turning the steering. Could these things be related to the steering pump? I know this isn't much to go on, but I'm hoping that this is symptomatic of something that's well known in these parts. Thanks

Post by **jblackburn** » 28 Nov 2010, 22:21

Does your car have this big slinky tube that goes down over my battery out of the airbox here?

If so, that's the sound of your secondary air pump (for emissions) winding down. No need to worry about it, unless it's screaming or screeching while the car is running in the mornings.

mc510 · Post by **mc510** » 29 Nov 2010, 14:16

Nope, I don't have that hose on my engine. I didn't know that there were different emission control versions for the 850, but I guess there were!

VolvoTurbo850 · Post by **VolvoTurbo850** » 29 Nov 2010, 14:41

there is a fan on the other side of that picture (passenger side) also in a black box that houses your ecu/ computer. It may run sometimes.

If not that then it would be your air idler pump where the throttle is (under a black cap). That would also give a whining sound but more of an air sound.

Post by **misha** » 29 Nov 2010, 20:36

Did you checked your headlight viper motor?

Mine was stucked on once because the clips which are holding it's housing broke and the little axle with a gear was appart from the motor.I guess the contacts of the motor somehow touched themselves in the process.

You can always disconnect it by pulling off it's jack under the hood.

Polvora79 · Post by **Polvora79** » 13 Apr 2011, 18:55

My 2000 v70, makes a strange noise,( like a speedy clock) on the MAF after I shut off the engine, do any body knows what should I do? maybe cleaning it?

Post by **misha** » 14 Apr 2011, 19:51

Maf sensor can NOT make any noise at all.There is no motor or anything like that in it...there's just a chip in it and that's all.

What CAN make noise is grey master relay for fuel system or iac(idle air control)valve.