Volvo V70 strange noise
 

Got a strange noise coming from my V70 2002 2.4 n/a - 133,000 miles

I made a video of it:
https://youtu.be/q3W8V4-oP2o

It seems to be coming from the under the drivers side of the car.
It is also intermittent, usually starts a few mins after I drive away with a cold engine. But is sometimes there after a 30min drive.

Also when I rev the car the noise doesn't seem to change, except when I let off the throttle it goes away for a few seconds and then comes back.

Any ideas?

...do hate guessing wrong.

I've always heard there's a brake booster pump. It maintains pressure when the ABS system is active. Might that be it?

Pull its fuse and see if the noise goes away.

I have tested the brake booster as per this video:
https://www.youtube.com/watch?v=2xzahn6Dh-o

It is a strange sound.. if you undo the oil cap on the engine does it go away ?

Might have to do with the exhaust..

Have you inspected the timing belt ? https://www.youtube.com/watch?v=4zbkJYkLxCA

I just tried this and no it doesn't.
But the noise definitely does go away when you let off the throttle when in neutral. Then usually comes back shortly afterwards.

Have not had a chance to try this yet, but will give it a go.
The car had a new belt + tensioner fitted 15,000 miles ago.

The test you performed is for the integrity of the diaphragm inside the power brake unit. I was referring to the pump which makes up the difference when brake fluid pressure is relieved by the ABS system opening the valve (so the wheel resumes spinning).

Sorry I misunderstood, thanks for explaining:regular_smile:

So do I just pull the ABS fuse to test this?

I assume so. It has a motor in it so it "has" to be fused.
Remember, this is an educated (ah-hem) guess on my part.

Thanks for the honesty :)

I assume if this was to cause some ABS warning light I could reset it with my copy of VIDA?

A VIDA can reset anything.

As to which fuse, if any, is involved, I'd assume all circuitry including ABS would be fused.

Have you driven the car up on ramps and stuck your head down there to locate that noise? ...or open the bonnet whilst it's making this noise?

Try focusing your hearing with an empty paper towel roll or some such.