07 XC70: sudden whine from front

[Durenol]

2007 XC70, 48k on the odometer. Went to drive it tonight and there's a noticeable whine coming from somewhere up front- it sounds like the engine compartment but I'm not 100% sure. It doesn't sound like the high-pitched screech from something electrical, but an upper-midtone slightly harmonic sort of whine like something mechanical. It kinda sounds like a hairdryer on the fastest setting but without the rushing air noise.

This car was just driven this weekend out to a relative, (~25-30mi each way) and I don't think the sound was there at the time... however I can't be 100% sure since although the sound is very noticeable when standing next to the car, it's significantly muted when inside with the windows shut and is completely drowned out by road/wind noise when the car is moving.

Any thoughts? Dying fan? turbo? The car otherwise seems to start and run fine and there are no warning lights on the dash.

[- Pete -]

Really need to get your noggin under there and pinpoint which area of the engine compartment it's coming from. Mechanics stethoscopes are like $3-4 at HF. You should be able to zero in on it with bare ears though.

[jimmy57]

A good first check would be power steering fluid level.

[Durenol]

OK well a steth won't help because the whine disappeared as suddenly as it came. Can't get it to happen this morning. Wonderful :/

Power steering fluid is actually high not low. Although it's rather opaque (isn't is supposed to be at least kinda translucent? it might be overdue for flushing). Engine coolant is at MIN level line when engine is cold, I forget, is that the way it's supposed to be on this car? Taking the oil cap off and putting a rubber glove over the hole gets sucked in, so the PCV isn't toast at least.

Random weird sounds worry me....

[- Pete -]

You’ll get a coolant message when running if it is low.