Hello;

 

Could someone help diagnose a problem coming from the front of my 2000 OBW. At slow speeds I can hear a whirring sound which increases in frequency with speed. It is not related to the engine, since if I switch off the engine and coast, the sound continues. Swerviing and turning have no effect, and the sound isn't a click. I've checked the tires for irregular wear, stones caught in the tread etc. nothing obvious comes to mind.

 

It's 100K km warrenty is about up, but I want to have an idea of what the problem is before taking it in to a dealer.

 

Thanks

The cooling fan is something you may want to look at. I would first spin it by hand to see if it is free wheeling enough to turn by the air passing through the radiator while traveling. If you think it is, try putting a piece of masking tape over the blades to the housing to prevent it from turning. Now, do this on a cool day when there will be no chance of the fan turning on, or just unplug it and make sure you don't overheat the engine. Make sure you remove the tape, or plug the fan back in when finished. If this isn't it, it may be drivetrain related.

 

When did you first notice the noise?

Was there any work done to the car right before the noise appeared?

What changed around the time you noticed the noise?

Does the noise go away when you lightly touch the brakes?

Thanks intrigueing

 

No, the problem persists even after lightly touching the brakes. To be more specific, it's a flutteriing noise rather than a whirring. It's something drivetrain related, since I can get the noise to occur when coasting with the motor turned off. The frequency of the flutter is related to the vehicles speed. When coasting at 20 km/hr the frequency is faster than at 5 km/hr.

Some tires get nosier at the end of their life. Plastic bag or other debris on exhaust system? Brake wear indicators? out of round rotors? Rust build up on the rotors may be dragging. Pads might not be retracting. Just ideas. Good luck!

John

If the noise happens when the brakes are applied, then I doubt it is the brakes. Check the CV boots for tears, it may be the early sounds of a failing CV axle. While you are under there look for any signs of rubbing. If the noise is not affected by turning left or right I doubt it is wheel bearings. Try jacking up each side and spin the tire (with the car in neutral) to see if the noise is evident. Try rotating the tires and see if that helps. Check the trans and diff fluid quality and level. Check the tire pressure. Is the noise coming from one side? Let us know what happens.

My outback started doing what sounds like the same thing. It is a constant whirl noise that changes with speed. I did notice that it changed when I got behind a semi truck on the 4-lane. It becoame intermentent. There was a big frost this morning and I am wonder if that was enough to make some kind a whistle effect with the roof rack. I am going to see if it does it on the way home today.

Even if you are right there. I would start by jacking it up and listening carefully while turning each wheel. I would also inspect all related componants.

These cars are known for the occasional wheel bearing and CV joint failure.

On my car the same sort of noise turned out to be the plastic shield that covers the bottom of the front.

One of the fasteners had broken letting it hang loose.

My noise must of had something to do with the frost or cold because the noise was not there on the way home from work. I am sure it was a noise from wind, but it did sound concerning. It should be frosting again soon and I will see if it does it again. If so I will try moving the cross bars on the roof rack.

It finally frosted again and my weird noise came back also. It must be the roof rack. I did not have time to move anything though to see what it might be exactly.