Hum Noise From Front

Uditha88 · April 9, 2013

Hi Folks,

Car makes HUM NOISE from front when Driving bit fast on Carpet roads. like "HMMMMMM"

Changing Wheel Bearings not worked.

What would be the cause?

NZer · April 9, 2013

MAy be its trying to Sing??? Jokes aside it might be the tyres and its design thats doing so. The wheel bearings would make the same noise even on the normal road. so the chances are its the tyres.

Rumesh88 · April 9, 2013

As NZer said it could be the tyres. Just to test it when you drive along a straight part of a carpeted road note the speed at the onset of noise. Then temporarily over fill the front tyres (by about 3 or 4 psi) and see if the same happens at the same speed. If it is the tyres you will have to drive a bit faster to get the same noise with over filled tyres. Be careful when you do this test and normalize the pressure soon after. This noise is due a phenomenon known as "tyre standing waves". Check the tyre for excess heat after a drive with noise. It is somewhat risky to drive continuously at high speed over a period for this reason.

Schiffer · April 9, 2013

Check for the wheel weights, whether one is missing or something,

NZer · April 9, 2013

On 4/9/2013 at 8:53 AM, Schiffer said:
Check for the wheel weights, whether one is missing or something,

The wheel weights wont cause noise machan. It will make it wobble.

Schiffer · April 9, 2013

On 4/9/2013 at 9:10 AM, NZer said:
The wheel weights wont cause noise machan. It will make it wobble.

true machan, but i've heard in some new cars, the wobble sounds like a hum from the inside if the shocks are good.

Uditha88 · April 9, 2013

Few details to add.

1. Wheel Alignment Balancing is due [Hve to do soon]

2. Factory tyre sizes are

175/65R14
175/70R14
185/65R14
185/65R15

But what it has is

195/65/R15

Rumesh88 · April 9, 2013

You are using tyres with a slightly larger balloon size. What's tyre pressure like?

nano31 · April 9, 2013

Is it your speed o/RPM meter cable driven? Just try oiling it up.

Uditha88 · April 10, 2013

On 4/9/2013 at 10:43 AM, Rumesh88 said:
You are using tyres with a slightly larger balloon size. What's tyre pressure like?

29 psi

Rumesh88 · April 10, 2013

You can inflate the front tyres to 32 psi and see if there is a difference just to identify the issue. Also you can try swapping front and rear tyres to see if it is a problem with one particular tyre.