That noise you're hearing is most likely the wheel bearing. The noise stops because the bearing isn't in motion. As soon as you put the wheel in motion the noise returns due to the bearing being bad. It's a common problem across the board on most Audi's!
is the humming coming from the front end of the vehicle? i have a 1996 explorer with the same issue. yes the noise come from the front but not all the time seems to make the humming noise when it gets hot
1999 Mercury front and humming noises can because by several things. Tire noises are the most common cause. A tire that is not wearing properly can cause a humming noise.
Answer Humming noise from front endI just got my car fixed with the same problem and it was the wheel bearing and it is gone. Was it a fwd car?
Could be many things but a front wheel bearing/hub assembly going bad comes to mind. Scalloped worn tires can give you a humming noise also.
Check the bearings.
Check the wheel bearing.
it would most likely be the bearings but in some cases sometimes the axle make a humming noise when traveling at high speeds.(front wheel drive)
i would first balence the tires then try replacing the wheel bearings if the noise is coming from a specific area on the car In example left front, right front etc.
A computer tower may make a surging noise rather than a constant humming noise if the case's screws are not properly tightened. Another reason for such a surging noise is the imminent failure of a fan.
when the pump is going out it will make a humming noise from the bearings even if the resivore is full.
newdiv vacuum leak, cat. converter comming apart, exhaust noise
The most common thing would be worn tires. It could also be a bad hub bearing. When you turn the car to the right does the humming noise change or go away? If so, the left hub is probably bad. When you turn left if it changes the right hub is probably going out.
Worn passenger side front wheel bearings.
it would depend on what kind of humming sound you are referring too. If you are over due on a transmission service or what not it will humm at higher speeds and as you slow down the humming slows with it, or if your brakes have gone bad it will make a humming sound once you hit over 30 mph. it could be a lot of things but those are some options to check out
Power steering belt?
Not much info there but my guess would be the the fuel pump.
i had some type of problem with my Transmission it had a loud humming noise whenever i start, the humming would go away when ever i start moving, but when i came up to a stop sign or a red light the humming would start, my friend who is a very good repair in all type of automotive told me my transmission oil pump was bad, well after he change the transmission oil pump the problem was gone.
I have a similar issue with my Stratus, except instead of humming, mine rumbles slightly. This answer is only speculation, but I believe that it happens because the power steering is stretched to the max while turned completely to the right. You'll hear a humming noise because the hydraulics are trying to pump even more fluid in order to turn further, but there isn't enough fluid in the system. Alternatively, your passenger-side front bearing could be worn out, but it would be much more noticeable than just a humming noise.
Fuel Pump, or possibly Cooling Fan.
change your wheel bearing!!
Some ideas coulb be something is lose and is just rattling or a mechanivcal problem under the hood.
A humming noise on a 1999 Park Avenue is caused by bad wheel bearings. When bearings are loose or worn they will create a loud humming noise that will get louder and louder as the car accelerates.
Electric fuel pumps can be expected to make a humming noise because they have an electric motor inside them. Excessively loud humming can predict impending failure. You should compare the sound to other cars of the same make and model. If the noise is significantly louder, it is time to be saving up for a repair. A trusted technician would really be a good resource for you...a good tech can tell a lot from the sound.
bad wheel bearings
One would really have to hear it in order to determine for certain. Are there any particular conditions existing in which the humming occurs? Wheel bearings are a possibility.