Chicago996

I've been hearing this noise for the past year but due to travel, have not been able to get to it till now. This is what happens: If the car is going 30+ mph and hits a road bump or a highway joint, then on occasion I get this loud humming noise from the right side of the car. Also, when I am taking a right hand sweeper, I sometimes get the same humming noise. The hum always goes away as soon as the bump is over or the sweeing turn is over but I want to re-iterate that the hum doesn't always happen...just on occasion, so there is no real way of predicting it. Also, it hasn't so far happened on left hand sweepers. Also, if the road bump is more on the left side of the vehicle, the chances are less of the humming noise.

So what is it? Wheel bearings? Fuel pump? The car runs like a champ, no gas smell, starts right up, accelerates and handles beautifully and is now approaching 31K miles. I bought it new, so I know the complete history. Any help would be much appreciated.

Cheers

Chicago996

*BUMP*

fpb111

Chicago996,
I would guess wheel bearing starting to go. If you swap tires left to right does it follow the tire?
If you press clutch when it is happening does it change pitch/intensity?

GaryAZ

Tire rubbing? On a RH sweeper you wouldn't expect the right side to rub. Are the tires oversized? Is the car lowered?

ivangene

how deep is the brake pad groove into the rotor ? might be the metal backing part of the brake pad rubbing on the top of the ridge of the rotor


that one is "out there" ehh?

Marlon

Does it still have any warranty left - I would get a 'free' dealer diagnosis first. Hopefully the noise shows itself to the techs. Alternatively, take the car to an Indy as well. They may have experience with that issue. Tough one. YOu could have a bad tire. Take the car to a reputable tire shop and they will take the wheels off, look at the balance, rim concentricity, etc. Could be related to a loose brake sensor??? You will find it and it will be a very simple fix, guranteed.

Chicago996

Thanks everyone. Is there an easy way to see if it is the wheel bearings? The loud hum I hear doesn't seem to be a tire related noise. I could be wrong though. The sound is more like a pump that was full of liquid and all of a sudden became liquid-less for a sec before getting liquid again---I suck at this, don't I

Car is standard suspension, not lowered, stock sizes all around. Warranty is longgggggggg over but it has been a VERY reliable 8 years. Hardly anything has gone wrong (knock on wood!).

Haven't tried clutching in/out b/c the onset of the hum is very sudden and it doesn't last longer than 1-2 seconds.

Could be something to do with the rotor. The sound only happens around bumps or right hand sweepers and even then is very random -- maybe it will happen, maybe it won't. I should also note that the hum won't last all the way through the right hand sweeper, sometimes by moving the steering wheel slightly, I can make it go away but it will likely come back again. Higher speeds, as in 30+mph result in a greater likelihood of the hum though.

How much should I expect if it is a wheel bearing job? Being clueless in this regard, does one replace bearings only on one wheel or all of them at the same time?

Lastly, if I have to get a dealer to diagnose it, should I be paying by the hour? I can guarantee that I can recreate the hum in 30 minutes or so by purposefully taking a few bumps or going on many right hand curves.

Cheers

Fiveoh

I had a similar issue with the noise on my 2000 C4. I checked the manual and it stated that when the PSM is on and operating, a "hydraulic" noise may initiate from the wheels. I can check the manual again and provide the page number later. Well, I was satisified with that response until one day I happen to view my car's front end, from a distance. I noticed something hanging down on the inside of the passenger front tire.

When I investigated, I discovered the plastic shielding that directs airflow to the brakes was hanging. The screws somehow came loose. I fixed it and haven't heard the noise again.

BTW, I'm new to the forums. Live in the D.C. area.

Marlon

Way to go - it was simple!

Chicago996

Alas, no loose plastic that needs screwing up. Thanks anyway gents. Drove it yesterday on city streets and couldn't get the hum at all. Not many right hand sweepers downtown so will have to take it to some highway ramps to see if I can't get a better handle on where the noise comes from.