Volvo XC70 high pitched noise in rain

What causes the high pitch noise underneath the car when driving in a downpour?

Is it a continuous high pitched noise, intermittent? Does turning the steering wheel change the pitch and/or intensity of the noise? At what point does the noise start (ie when the rain starts, when it gets to “torrential downpour” levels?

Continuous high pitch noise when there’s enough water on the road. Same thing also happens with slush. Living in PNW it’s almost granted when driving I5 up to Seattle because water collects on the road.

Maybe your serpentine belt is slipping when it gets damp or wet, in which case you might need a new belt and maybe a new tensioner. What year is this car?

an old tensioner can also be a suspect

grease will dry up with time, water can become a trigger to make it squeal?

Tires? I know my winter tires and summer tires don’t sound the same, especially on wet roads.


Same thing happens with both my regular tires and studs.

It’s from 2006

I recall something similar in a big GM car 10+ years ago. Some component in the exhaust system vibrated at a high pitch. It had to do with exhaust heat expanding something and water cooling it, and the net result was a high pitched sound. I think GM had figured it out. You may find Volvo has figured out your situation and has a service bulletin about it. Ask dealers and the corporate contact offices listed in your owners manual.

If there is an internet discussion group specific to Volvos, this situation might be discussed there, too. Anyone know a good Volvo site?

Years ago I had a front wheel bearing problem on a VW Rabbit, making a sort of whine/growl noise. It would become more apparent when the road was wet for some reason. I think the wet road masked the sound of the tires on the pavement, making the wheel bearing sound more apparent. If it’s the wheel bearing pretty soon you’ll notice it even on dry roads, worse the faster you go.

Good idea to check all the pertinent fluid levels of course. Transmission, differential, etc.