Odd Volvo 240 Noise

[Volvo240swag]

I drive a 1990 Volvo 240 sedan with the odometer broken at 264k.

This car is also lowered and straight piped.

I've spent weeks on multiple forums, and have spent quite a bit of money with no solution!

To the issue at hand:
Whenever I drive faster than 40 MPH, this whistling noise develops.
It sounds like it is coming from the front passenger side in the engine bay.

Sometimes it won't do it at all, then it will decide to do it out of nowhere.

At times, it had two tones, but either way it's an annoying whistle sound.

When this occurs, the performance of the car is not harmed.

I've hand revved it for minutes on end, and it won't duplicate the sound, other than while driving.
View the video below to hear the sound: it's loud, but my camera cannot pick it up well!

Using headphones is advised!



One more note, the temp gauge goes slightly above the middle mark, but I have a suspicion it's faulty since it goes halfway down the middle mark at times, and nothing is smoking.

I was told it could be a carrier bearing, but don't those produce more of a grinding sound?



Any help would be appreciated!

[oldschoolvolvo]

my guess would be a bearing of some sort as well.

since it doesn't whistle when you rev it by hand, it's not an engine pulley...that leaves something in the driveline. it may be helpful to run the car on a lift, etc so the driveline can be in motion without wind noise to better isolate where the whistling is coming from.

[Volvo240swag]

I was told it was a carrier bearing, but that wouldn't make noise some of the time, and travel to the front end.

It was put on a lift today, and the noise was not reproduced.

When I am at highway speeds, throw it in neutral, and turn the car off, it still produces the noise. I've also been told it can be caused by the wind. Is that possible?

[Daisy Driver]

I am new to the Volvo world, but not to mechanics by common sense.

You need to reproduce the noise consistently to determine what causes it and use the old Sherlock Holmes method, eliminate the obvious. For instance, take her out I see if the noise is there when going down hill at speed, but no engine power. You might even try neutral. If the noise is still there, then you know it is not engine, power, transmission or drive line related. Being able to duplicate the noise will tell you where to look. Drive line noises change with load. This could even be related to wheel bearings or brakes. I doubt that it is wind because you would have to have damaged something visible to cause it.

Bob

[rgk]

Check for a vacuum leak in your components. When is the last time you've changed your intake gasket?

Also, check to make sure your air box thermostat is not stuck in the closed position. If you've never heard of this, a google search will reveal what you need to know.

[Volvo240gang22]

Was this resolved? I'm experiencing something very similar at the moment and am quite stumped by it.

[MIB]

It can be the driveshaft support bearing

[volvolugnut]

Might be the speedometer shaft unless this 240 is new enough to have electric speedometer. They changed somewhere between 1983 and 1987. My 1983 has a whine sometimes. You could try to disconnect at the transmission and see if it stops. Then you could lubricate the cable.
volvolugnut