lexixel

Hi,

The SC I recently bought is quite quiet except for a helicopter noise at speed.

This noise becomes obvious at around 70 kph (40 mph) but can be noticed at lower speed (volume much lower). I don't think turning the wheels or braking makes a difference.

Since it's speed-sensitive and there's no noise when the car isn't moving, I guess it's related to the wheels. I've just replaced the rear tyres last weeks; nothing changed. I've checked the tyre pressure today; may have got a little improvement (not sure) but the noise is still there.

Is this the wheel bearing noise? Or is this tyre noise? Could the differential make this kind of noise (the only other thing I can think of that's speed-correlated)?

Also, as an aside I pulled the fuse on the te/ti steering the other day because I'm too lazy to use techstream. I swear there's a noticeable improvement in the steering accuracy and feel. Really don't know why.

Coleroad

Jack up each corner. Then grab the top and bottom of the tire pushing with one hand pull with the other back and forth. Looking for play. This would be the first step

ruger

Coleroad has the right idea to check your wheel bearing, it could be something as easy as a wheel balance problem..

lexixel

You may be right. I remember there was some camber wear on the rear tyres that were taken off (inside).

I'll check for play in the wheels, too, but probably it's just the geo.

lexixel

Just realized the old tyres are runflats (Bridgestone Potenza RE050A). The new ones I've put on are Dunlop Sport Maxx RT2. They did noticeably improve handling.

416tt

iTrader: (1)

Helicoper noise is definitely the bearings. I changed my bearings with hubs a while back. It was exactly the same as you say.

lexixel

would it be necessary to change the hub as well? I'd think it's just the bearing

lexixel

Hi, so I jacked up each corner and tested the wheels in all directions. No wheel was wiggling. I also span the front wheels (parking brake was set), and they seemed ok. There were some sound when I span them, but I assume that's coming from the brakes?

Did your wheel(s) wiggle / wobble before you changed the bearing?

Should I go to the dealer and get an alignment and ask them to check the bearings?

thanks

texsexlex

iTrader: (3)

...there's a chance that you could need a bearing & not get the wiggle,this just happened recently with my wife's car. It had the noise & we did the wheel check, passenger side had some play, so we changed the bearing. After getting the car back together & road testing it, we still had the noise. The bearing was going out on driver's side, which didn't have any play in it,when we did initial testing. A load test might be able to help also. Drive the car on a straight road, give it a turn to the left, then to the right. If the sound goes away during the turns, this will let you know of a bad bearing & which side it is on also.

lexixel

I've done turning the wheels at varying speeds but there wasn't any noticeable change in the noise. I think I'll probably just drive and see what happens. In 10k km I'll change the front tyres. Maybe the noise will get louder before that and I'll find out which bearing is bad, or maybe it's just crappy tyres. The new rear tyres do feel much softer at speed bumps, which there are countless and increasingly aggressive here (I probably passed 50 of them in 30 km just now). There're 7 just to get to the main road.

Bgw70

There is a chance your run flats are creating the noise. Since you only changed the rear tires, I would guess you still have run flats on the front. Worn out tires will make considerable road noise.

416tt

iTrader: (1)

Hi

Sorry for late reply..

I changed hubs because i figured munes would get damaged when trying to take out.. hubs werent expensive so thought id make it quick and easier.

Run flats do also make noise .. but it seems like this is louder then tire sound.

I had same issue. Lol god it was annoying .. changing bearing solved it.

How much mileage does your car have?

lexixel

Hi,

It has about 100k miles. I wouldn't be surprised if the bearings are going, but I'll keep driving for a while and see. I also am suspicious whether the tyres can make this much noise.

Yesterday I did notice that once over 60 mph the noise becomes less noticeable; I would say this louder noise at higher speed is tyre noise - definitely sounds like it - or maybe the noise just changes its tone at different speeds.

lexixel

adding 0.2 bar to all the tyres seems to have fixed the problem. since I don't have a tyre-pressure gauge, I only measure at gas stations. usually, I add 0.2 bar to the recommended pressure. this time, I added 0.2 more.

Bgw70

.2 bar = 2.9 psi.
If you added this amount to hot tires then you may be under inflated.
Did you check the tires when they were cold?