1999 V70 XC humming sound between gear shifts at 2300 rpm

Adriaan · Post by **Adriaan** » 04 Nov 2007, 13:06

This site is really wonderfull and has helped me quite a bit figuring out the 99 V70 XC I bought last spring.

I have the following issue that I cannot put my finger on:

When I accelerate I hear a low humming sound for a few seconds at approx. 2300 rpm between gear shifts (between 20 and 40 mph). I changed the fuelfilter and it seemed to improve but after a couple of weeks the sound came back. Does anyone have an idea what this is and if it fixable?

Thanks
Adriaan
New York

Post by **MadeInJapan** » 04 Nov 2007, 13:35

It would be good to know how many miles. I have a hum too on our V70 but I believe it's because of the engine mount and strut brace mounts that I replaced with poly mounts...it's harder and transfers more vibrations at certain RPM's. Anyway, on a wagon, I've heard that the exhaust can also vibrate against the car's body at certain RPM's when there are more vibrations. Do you hear it as an engine/transmission hum or other "body parts" hum?

Adriaan · Post by **Adriaan** » 05 Nov 2007, 05:58

Thanks.

The car has 85000 miles on it. My first thought was that the hum was engine related, but the bodypart theory is interesting. It always seems to happen when the engine is at a low rpm for its gear. At 2300 rpm, especially when driving up a hill, the dark sound of the engine gets accompanied by a sort of rattle. The only way to get rid of it is to accelerate past this point. Maybe the exhaust?

Post by **billofdurham** » 05 Nov 2007, 15:18

One of the things I have found that has been common to all of my Volvos is rattling from the various heat shields on the exhaust. In some cases they have worked loose and in others they have become bent. In all cases they have rattled.

Bill.

sony2000 · Post by **sony2000** » 05 Nov 2007, 17:24

The turbo starts to kick in around 2000 rpm and it has a hiss or humm of its own.