I'm wondering if anyone can help on this issue, it has me baffled because I can't even figure out what sets it off!

It's a mid-pitch hum or whine that comes from the passenger side. Not a high squeal or a low rumble. I think it's coming from the front but I'm not 100%, a passenger said it may from the back. The part I can't figure out is it comes in at various speeds and various RPM's, and a various times, but I think always under moderate acceleration. I'd say like 10% to 15% throttle and It'll start to hum. I can be going 80MPH or 25MPH, it'll still do it.. It's do it in various gears, all the way from 1st to 6th.. It'll kick in somewhere between 2K and 3.5K RPM, but it doesn't happen every time, only under 'certain' conditions whatever they may be..

Any ideas?

 

open your rear seat to expose your trunk and see if the noise is coming from there. . . If so its probably ur fuel pump.

 

I have the same thing going on it is definatley coming from front passenger side (at least in my case) bringing her to my mechanic next week for a few things. I'll have him check it out and get back to you on it

 

Thanks 02A4kid, I definitely appreciate that!

Would't you know it didn't make the sound yesterday or this morning Pa4ul, drove home last night and back to work this morning with the seats down but not a pip. I'll keep trying with it but do you think I'd feel some sort of hesitation or other performance symptom if it was the fuel pump? I've never had one go bad/out on any of my cars before, is this what happens?

 

nah with the fuel pump u will hear a loud hmm from the trunk. Then one day your car with either stop or not start. Easiest way to check if its the pump is to check pressure at the fuel rail. The silver line near the manifold with a small flathead cap at the end. undo the cap press on the inside and if u have strong flow u know its not ur pump. But that humming from the front ive never actually heard of. i would wait for a4kid to reply.

 

pa4ul do you think my humming could be the result of a wheel bearing going bad? I won't have her in until at least Wednesday this week but as you know we all bring our Audi's in just for them to say on occasion "oh ya we couldn't find anything" lol just looking for a little insight so I could try to narrow it down a bit for my mechanic

 

My passenger wheel bearing has gone bad after i slammed into a curve. Sounds like i have mud tires on the passenger side (light roar,roar sound). sometimes it hums, sometimes it doesnt. If it is the fuel pump, you will also hear a hum but you would hear it in the passenger rear. i changed the fuel filter and the hum went away. Sometimes the hum from the fuel pump can be heard on start up. Just my experiance!

 

Wow Smyley, you may have led us down a road to fixing the problem, the fuel filter! I'm almost 100% sure that mines never been changed and the car's in the 95k's. The fuel filer is around the top left hand side of te engine bay I think, which is where the noise seems to be coming from. Mine doesn't sound as low as the wheel, and If it was a wheel bearing I think it would make noise more often than what I described originally. What are your guys' thoughts? It makes sense to me to look at it, the noise coming only at a certain throttle percentage at many different speeds and gears seems like the problem could be the old fuel filter making fuel flow slow enough to build pressure and make a noise?

A4kid have you ever replaced your fuel filter?

 

fuel filter is seriously about a 30 minute fix. Just make sure u purchase the correct version as their are two different filters for the b6 model. As for the hum i wouldnt rule out a wheel bearing going out. IT will produce that hum from the wheel thats going bad.

 

^^^^^ Like pa4ul said, the wheel bearing can be a big possibility, My passenger bearing can get loud and have some vibration. Im going on ebay to buy the whole knuckle.

When my filter was clogged, right before I changed it it would do it at any RPM. I changed it right at 104000 (I think). My 04 CVT fuel filter was located under the rear passenger door, right above the plastic cover. you have to be careful with the fuel line clips! They are brittle and break easy!

Here is a DIY for replacing the fuel filter (Hope this isnt illegal: from another forum) http://www.audizine.com/forum/showth...er-Replacement