Humming Sound while driving

driver_guy (driver_guy) 2012-02-14 01:52:49 +0500 #1

I am facing a heavy humming sound in Cuore,06 (85K driven) like "goooooooooonnnnn" when car is running above 30 Kph or so. Sound changes tone when accelerating or decelerating.
I had recently changed gear oil (ZIC FF 75W-85). So I thought it might be the gear box sound. But the sound even comes if make the gear neutral while running.

The sound is Not there when idling or when driving at slow speeds below 30Kph

What could be the possible causes

Gearbox problem?
Exhaust leak?
Wheel Bearings?
Suspension?

Or anything else? How can I narrow down whats the problem????

formula2012 (formula2012) 2012-02-14 01:59:59 +0500 #2

wheel bearings for sure if ur car is running and in neutral,no gear problem,no suspension issue,exhaust doesnt sounds like this:)

balochfaheem (balochfaheem) 2012-02-14 02:07:14 +0500 #3

change the wheel bearings.

irfansiddique (irfansiddique) 2012-02-14 02:10:01 +0500 #4

check bearings of
Wheels,
main Pulleys &
Generator Pulley.

irfansiddique (irfansiddique) 2012-02-14 02:14:07 +0500 #5

check all bearings
generator
AC
main pulley
wheel

ansarghani (Syed Ansar Ghani) 2012-02-14 02:58:07 +0500 #6

If the sound increase when you give race while standing then the problem is in some engine bearing, not in the wheels... it can be water body (pump), generator's or timing belt pulley's bearing...

AsadGhumman (AsadGhumman) 2012-02-14 04:43:34 +0500 #7

most probably wheel bearing is making noise. Car ko Jack per laga kr bari bari saaray whels ko hath se free rotation de kr check kro. Even if slight se b chu chu ki awaz aati hai to wo wheel bearing problemetic hai q k speed k saath awaz increase kr jaati hai.

If all wheels are OK then Inner Axle bearing ki problem b ho skti hai but wheel bearing ka issue ziada lagta hai

driver_guy (driver_guy) 2012-02-14 04:46:30 +0500 #8

@formula2012 @balochfaheem @irfansiddique @ansarghani @AsadGhumman

Thank you all very much for replies.

Now I think wheel bearings can be checked by jacking up the car and shaking the wheel with hand to see if there is play. (Correct me if I am wrong)

Regarding Generator bearing or AC pulley bearing, how can I check if it is faulty???

AsadGhumman (AsadGhumman) 2012-02-14 04:55:11 +0500 #9

Yes you are right about shaking & checking any play but in some cases, initially there is no play at all but bearings are making noise so check it by rotating the wheel with hands while putting the car in neutral & handbrake down so that wheel can move freely. Rotate the wheel & listen to the slightest sound.

khalidumar (khalidumar) 2012-02-14 04:57:28 +0500 #10

101& bearing issue

ansarghani (Syed Ansar Ghani) 2012-02-14 05:08:57 +0500 #11

IMO one can not find out wheels bearing problem by jacking up the car and rotating the wheel by hand. by jacking up the load will relieved from the bearing and it will not make any sound even if faulty.
If you hear the sound while giving race (not running) the problem is with some engine bearing and if you do not hear the sound the problem is with wheels bearing..

alikhan7 (alikhan7) 2012-02-14 05:13:56 +0500 #12

100 % agree had same issue with my coure and culprit was compressor bearing

Marlboro11 (Marlboro11) 2012-02-14 05:27:55 +0500 #13

or maybe you have a humming bird inside your engine

sadiaali (sadiaali) 2012-02-14 05:40:53 +0500 #14

oh coure change this model best solution.

onlyfaith (onlyfaith) 2012-02-14 06:26:28 +0500 #15

check AC/alternator bearing and belt tension ..

driver_guy (driver_guy) 2012-02-14 08:15:25 +0500 #16

The sound is not noticed at idle revving. It is only while driving...

And any method to check alternator/AC bearings???

supraman2jz (supraman2jz) 2012-02-14 13:28:28 +0500 #17

My car had the exact same symptoms, got the wheel bearings changed and the sound and vibration went away like it was never there.

ansarghani (Syed Ansar Ghani) 2012-02-14 16:46:54 +0500 #18

If the sound is not there while revving, then the problem is related to Wheel bearing... front wheels tend to deteriorate more quickly then the rear one..

driver_guy (driver_guy) 2012-02-15 03:05:33 +0500 #19

Now I have even more difficult question

which is best bearing brand available?
where to buy in lahore?
If anyone knows good mechanic for this job please share

ansarghani (Syed Ansar Ghani) 2012-02-15 03:45:23 +0500 #20

I always prefer NTN bearings... Koyo and Niachi are also good... beware there are tons of counterfeit Chinese bearing available... buy your bearings from a trusted dealer... one can not differentiate fake bearing from a naked eye...