Hello guys,
S40 07MY

I'm having humming sounds like a pump from the back. I've had this from the moment I own this pre-owned car. It's been 3 months I owned this. Odometer going over 75000 miles.

Here's description :

1. Usually starts to happen over 50mph
2. Sometimes, it's fine even though I reach up that speed.
3. Tested high speed slalom, the sound stays constant left or right.
4. Sounds like a pump. Doesn't have something to do with throttle level though.
5. When the vehicle slows down, it goes off

Is this normal for S40?
If it's not, what would be the culprit? Any help please

 

Could it be wind noise? Like something sticking up into the windstream? Sunroof? Sharkfin antenna?

 

I hope so.. But it sounds like something is rotating. Any idea?

 

Tire noise? You might try rotating the fronts to the back.

Wheel bearings. They tend to make a grinding sound.

Fuel Pump. This one shouldn't make noise you can hear.

All just guesses.

 

Thank you! I'll check it out. It seems to be both of wheel hubs, haha. Out at the same time.