Weird Noise For The Mechanics

[Prudie]

For the last week whenever I take my foot off the accelerator I hear a weird fluttering noise which seems to be coming from the nearside front. I could describe it as running a stick on a venetian blind or rain on a tin roof or card stuck on bicycle spokes. It gets worse if I brake. Anybody any ideas what it could be?

[tonyav]

Check the plastic wheel arch liner isn't loose.

[Buenchico]

Get the tyre checked out too. (I took my car into the garage for what I was sure was a dodgy wheel bearing, causing noise from one wheel. It turned out to be a misshapen tyre).

[Prudie]

I will get those checked thanks although I think it must be more serious than that. I'm not sure why those things would only make it noisy when I didn't have my foot down but I'm no mechanic.

[EDDIE51]

Faulty wheel bearing is the most likely cause.

[bhg481]

Is the frequency of the fluttering dependent on the engine speed or the road speed or neither? In other words, does the noise change if you change down a gear, does it change as your road speed steadily decreases or does it always have the same frequency?

[Hymie]

When you have your foot on the accelerator, torque/power is being delivered to the front driving wheels, causing them to turn (assuming that it is a front wheel drive vehicle). When you take your foot off the accelerator, no further power is being delivered and the front wheel torque is operating in the opposite rotational direction (applying slight braking to the engine).

So as EDDIE51 says it is likely to be a wheel bearing, or even a CV joint – which is noisy when rotating under no torque (or a slight reverse torque).

You could try dipping the clutch (with the vehicle coasting) to see if that makes any difference to the wheel noise. Dipping the clutch will reduce the engine braking on the road wheels.

[Prudie]

I will look into some of the suggestions and get more description of the noise and when it happens but should add it's automatic and rear wheel drive.

[gulliver1]

If you are lucky, it might just be wheel balancing, happend to me once thought it was wheel bearing but just needed balancing ,go to a tyre fitter, good luck.

[bhg481]

If it's an automatic you can push it into neutral to disconnect the engine from the wheels - worth a try to try to isolate what the noise is dependent on. The fact that it is rear-wheel-drive eliminates a CVJ problem.
Another point to bear in mind is that noises travel around the car body and can seem to come from one place when, in reality, they come from another. I had a noise I was convinced was coming from the rear nearside which was eventually traced to a front strut. Keep an open mind and try to get someone outside the car to listen, if it's practical.

[MantaRay]

Loose wheel nuts perhaps?

[Prudie]

I have had another listen today in light of above:
Only happens when foot off accelerator, sound frequency slows as the car slows, more obvious when braking. Happens in a straight line and not clunking so CV joint unlikely. Definitely like that sound when you stuck card in your bike spokes as a kid. I will have to get a garage to look at it.

[bhg481]

Rear wheel drive cars don't have CVJs, so it can't possibly be that. I've only had one wheel bearing failure and that was more of a buzzing/humming noise than the noise you describe.
Did you try pushing it into neutral or forcing a downshift on the gearbox to see if the noise changed?

[Prudie]

I know this is a really old post now and has slipped of the motoring section but wanted to give an update just in case any contributors would like to know what it was. I finally got it into a garage this morning, the guys at work (150 + qualified mechanics) had scared the pants off me by thinking it was a slipping diff and a very expensive repair.
Anyway turned out to be a loose heat shield hitting the prop shaft. A fiddle and tighten, job done. £48 :-)