Flat tire noise no flat tire?

[Riss9]

My vehicle is making a noise like a flat tire but no flat tire it is the loudest when my foot is off the gas and im coasting I have had the bearing checked that is not the problem of course the mechanic couldn't hear it when he took it out but as soon as I left it started doing it they also told me the motor mounts are a bit loose but they didnt give me much information on it they kinda rushed me out my car is also vibrating quite a bit anyone have any thoughts on what it could be

[65comet]

My guess without see it would be a CV joint going bad.

[denisond3]

Four things I would be looking at: First with each wheel jacked up off the ground one at a time, make sure they are snug in the wheel bearings - that the wheel wont move when you shake its top in and out, with your hands at the 12:00 and 3:00 positions. Second, make sure the lug nuts are all still snugged up - by checking them for tightness when the wheel is on the ground.
Third, if the rear tires have been on the car for several thousand miles, they can wear in a pattern that causes noticeable noise, usually louder the faster you go - but still sounds like a growl, not a hum. Often you can rub your hand around the tread and feel the pattern of uneven wear.
Fourth I would check that the front hub nuts are properly torqued up. A loose hub nut will let a wheel bearing run with play in it.
Lastly - if you have a bad inner CV joint, it can cause vibration and noise, though the vibration might only be when accelerating or keeping a steady speed - and might cease when you are coasting. The inner CV joints have three sets of needle bearings running in three channels. They can be out of 'true', but it wont be easy to see, nor to feel unless the CV axle is shaken when the near wheel is jacked up off the ground.

Less common could be a tire whose tread is delaminating from the carcass. If it were a front tire, you could spin the tire when its jacked up off the ground, and see that the tire was going out of round at speed. Be careful with this procedure, since with only one tire turning, the speedo would say 40 when the wheel was spinning as if the car were going 80 mph. Swapping a tire back to front would let you see this with any of the four wheels. Also - check tire pressures. They should be within 10% of the same pressure reading. I once had a severe vibration on a Honda Civic I bought cheap - because of the severe vibration. That turned out to be a tire that had not been mounted properly, and wasnt fully seated onto the rim of the wheel.

If you have or two motor mounts that are loose enough or soaked with enough oil, that could be letting the metal of the engine touch the metal of the car at some point. This would make a very noticeable noise.
good luck with the car....

[hakachukai]

Is your Escort automatic or manual?

I'm guessing that you have some bad or loose engine mounts. You can test that by (safely) parking on a hill, then drive up the hill in reverse. You might also be able to do the same test on flat ground if your E-brake is strong enough to significantly resist the car from moving.

This will put a similar torque on the engine and drive train as if you were coasting/decelerating at a higher speed.

If you when you start backing up the hill your hear some CLUNKing... then you probably have some bad / loose engine or transmission mounts.

It might also be possible that you have some suspension components that are loose. You might consider jacking the car up (safely) and giving it a shake down.

While it is in the air, give each wheel a good shake down. Grab each wheel at 10 and 2 O'clock and try to rock it back and forth. There should be no clunking or free play at all.

Grab each wheel at 12 and 6 O'clock and try to rock it in the up/down direction. There should be no clunking or free play at all.

Give the strut on each wheel a good shake down. They are supposed to be solid, so if anything moves it needs attention. Pay attention to the suspension components near the strut. As you raise and lower the car on the jack, nothing should be moving in a way that shows free play.


Back to the driving test---
If when you back up you hear snapping, grinding or creaking sounds, then you need to check out your CV-axles.

Throw your video camera up on the dash of your car and take a video of it happening while you are driving. Then we can get a better idea of what is happening. Just do it safely. Don't crash your car because you got distracted playing around with the video camera :-P

Hopefully that helps... let us know how your testing turns out.