Humming from undercarriage

[Genie47]

My car has just gone past 50k mileage. As I travel on the expressways, I hear this "Ngong..ngong..ngong....." humming. I figure it might be my bearings.

 

I've talked to other car owners with cars utilizing torsion beam suspension for the rear and they all say that it is tell tale of worn bearings. Without fail, they say it is the rear.

 

Supposedly that it is true that my bearings are worn, why is it always the rear ones on a beam axle suspension are the first to go?

[Sky8807]

if your tyres are used to abt half, chg it first.

A friend of mine bought a second hand car and when i test drove, thought its the bearing or suspension kaput. But visual check could not find anything, suspect tyres so ask him to refer to mechanic. Finally its the tyres that cause the problem.

Edited October 1, 2005 by Sky8807

[Genie47]

My tires are new. Changed in Apr. Maybe I should reduce the pressure. Running at 33psi.

Edited October 1, 2005 by Genie47

[Sky8807]

lower it to 30 psi might reduce it. what tyres are yours

[Genie47]

Kumho Ecsta 712s

[Sky8807]

probability of noise generated from tyres is high. U can swop tyres from friend and confirm this if you want. or ask tyre shop to confirm, if noise still there don't buy tyres from them.

 

tyres noise normally generate at cruising speed say above 65-70. the higher speed will sound louder. drive near isolated area near kerb and down window to hear, might hear the noise source if place is quite.

Edited October 1, 2005 by Sky8807

[Koren]

my front left undercarriage also has this problem. @ 1st i tot it was the tyres running out, so i changed it.. but still hav the sound leh..

[Sky8807]

normally, if we are not sure the cause, the logical steps are tyres first then the bearings, suspension and other related components.

we are referring to this kind of noise as described by genie only.

[Genie47]

Such humming noises are due to 3 things. Tires as suggested by Sky, bearings or worse drivetrain deterioration!

[Koren]

wa.. duno under warrenty or not.. i didnt do aniting to the suspension..

[Genie47]

Drivetrain usually 1yr warranty only.

[Koren]

my vios just up 1 year~~ today~~

[Potheader]

Wah.. So suay.

 

Anyway you sure you didn't do anything to your suspension?

[Koren]

haha.. really la.. i did everything except the suspension..

[Elfenstar]

Sounds like the wheel bearings are gone... Is it a continual grinding sound?

 

Get the car jacked up and try shaking the wheels. If at least one of them moves, then it would most definately be the wheel bearings. If its not, just reply to me and i'll try and do some internet mech work 50k's is too little for the bearings to go though...

Edited October 1, 2005 by Elfenstar

[Genie47]

It is continuous. I've reduced the pressure. Still there.

 

I treat this car rough. I go through bumps as if they are not there and I did have this hard bump from clipping a high kerb from Parkway Parade's MSCP.

[Genie47]

I did more Internet searches. These are the symptoms of wheel bearing failure:

 

1. Rumbling noise (can be confused with aggressive tire noise or vice versa as suggested by Sky).

2. Oil leak from end of axle housing (fixing this is cheaper than replacing bearings).

3. Squeaking noise

4. Grinding noise (very bad).

5. Slop and play with wheel hub when wheel is removed.

6. Any uneven feel while rotating the wheel while off the ground (tested as suggested by Elfen).

 

For my case or for most cases, I think it should be rumbling/humming noises. I think for mine, it is the rear because if it is the front:

 

1. The rumbling noise will increase as the vehicle turns. Mine increases when car is faster.

2. Looseness and excessive play with the steering wheel.

3. Pulling to one side while braking.

[Koren]

the funny thing is that the noise only comes when my car hits 60~80 kmph.. and when turning right.. no problems when turning left..

 

i think its something wrong with the rims.. i changed my front wheel to the back.. now the sound comes from the rear undercarriage.. but the rim looks normal to me.. afraid it might fly out one day when i'm driving @ high speed.

Edited October 2, 2005 by Koren