Hey guys,

So recently I have noticed a sort of humming noise coming from below me while driving. It is not engine related because when I disengage the clutch the noise continues. I was thinking maybe wheel bearings but the noise happens constantly while driving straight and cornering to either side doesnt seem to change it. I have quattro so I was thinking maybe something related to the differential? Are there any commons dif problems? Maybe fluid? I also noticed one of the cv boots is leaking but I am leaning more towards a diff problem.

Any ideas?

 

My car isn't Quattro so I can't be completely sure of this, but perhaps your center driveshaft bearing needs to be replaced.

 

Don't let the CV boot leak for too long, or you will wind up with a big bill.

 

Are you sure the sound does not change when turning? How noticeable is the humming?

Jack the car up, grab the wheel at 3 and 9 and give it a shake to check for slop. Do the same at 6 and 12.

If the sound does not change when turning and the wheel feels solid it could be the rear diff.

Usually if one wheel bearing fails it is not uncommon for the other side to fail around the same time. However I think it would be an extraordinary case for both sides to fail at exactly the same time.

 

Ok after some more listening it does indeed change when turning. When I turn left, even ever so slightly it gets much more intense. Would this indicate front right wheel bearing? Even the slightest turn left makes it humm...

 

I am thinking it might be the cv joint, the boot is broken and mostly empty of grease, could that be the noise?

 

Inner or outer?

Your other post about the humming changing when you turn makes me think wheel bearing too, but obviously a torn CV boot with no grease in it is a pretty big indicator lol

 

Outer.

When I had the car jacked up i spun the wheel and it didnt seem to make any weird noise which makes me think it isn't the wheel bearing but that it is the CV joint, I will go with that first and then see.

 

Yeah if the boot has been torn for a while the joint should probably be replaced anyway. I'd recommend either buying just the outer joint from Blauparts or ECS and rebuilding it yourself, or getting a re-man OEM axle from Raxles. DO NOT buy the cheap shitty chinese EMPI/FEQ axle from ECS. They're garbage.