S80 Wheezing noise

[k6chris]

My S80 2.4D has developed a slight wheezing noise, which seems to be linked to the engine revs (rather than actual speed). It does not seem to affect power or MPG. Most noticable at low speeds.

Any idea what it might be??

[glengibson]

try listening with aircon on and with it off, see if the makes a difference

[jerryt]

Sounds like a vacuum leak or possible blocked PCV valve! I would also check bearings in pulleys etc.

[k6chris]

Originally Posted by glengibson

try listening with aircon on and with it off, see if the makes a difference

Thanks for the reply. Aircon on or off makes no difference.

[k6chris]

OK, long trip in the car - 500 miles+ No loss of power or fuel economy, but still the noise. Someone has suggested it could be the alternator bearing starting to go? The 'wheezing' could be a bearing noise I guess. Is this a common problem?? Car has done 120k.

Thanks

[dped]

When you put your foot down then gears change do you get a sound like a dump valve on a boy racers car ?

Read a lot that this is caused by the Turbo Control Valve following link shows how to clean it but can buy them for around £40 ish

https://www.youtube.com/watch?v=BPtABczQk3E

[k6chris]

Thanks for all the suggestions so far, but none seem to fit. I have noticed that at the same time the car is making noise when steering the car at very low speed, ie parking in a car park. I don't know enough about how the power steering to know if the two could be related? All thoughts welcome.

Thanks

[Tatsfield]

Bearings or pulley for power steering hydraulic pump?

[k6chris]

Originally Posted by Tatsfield

Bearings or pulley for power steering hydraulic pump?

Would that noise be proportional to engine revs? If so, we may have a winner!!

[Tatsfield]

Since the power steering pump is driven by the engine, I assume it would. I have no relevant Volvo experience with power steering pumps but on a previous car the problem was that the belt drive pulley rubber damping layer had perished and allowed the rim of the pulley to slip making a screeching noise which got worse if more power was applied to the belt at such times as when the steering was fully deflected or extra electrical power was being demanded of the alternator, but the steering was the main cause of drag on the belt. If this is the case with the Volvo, any problems with the belt might have serious repercussions if it came off the drive pulley. If I've got this wrong and this does not apply to your engine, I do apologise.