Whine sound with speed

zmnewzealand, Dec 11, 12:41pm
hi guys I have a 2000 mazda demio 1.3 manual, iot seems to have a problem of a whining/ thumping sound which increases higher the speed and decreases when slowing down, seems to be coming from the front of the car was thinking maybe a wheel bearing? or could it be the manual gearbox? thanks
zmnewzealand, Dec 11, 12:55pm
forgot to mention can change gears without any effect on the noise
mohaka, Dec 11, 12:57pm
What about if if you coast in neutral?Noise change-could also be diff.Hard to sometimes work out where sounds coming from,as only appear under load.
mm12345, Dec 11, 1:03pm
I suggest that if you don't know how to check to see if it's a wheel bearing yourself and at least confirm or eliminate one of the possibilities, then take it to someone who does ASAP.
IMO could be tyre(s), bearing(s), gearbox/diff, inner CV or something else, and it could be trivial and simple to fix, or expensive, or potentially dangerous.
dingo011, Dec 11, 1:21pm
Left mother in law in the boot? Has happened to me before.
kazbanz, Dec 11, 1:31pm
first thing Id check would be the tyres.--easiest thing to check -then get a mechanic check the wheel bearings.
poppy62, Dec 11, 1:59pm
My opinion is Diff whine, wheel bearing or Cambelt tensioner depending on the pitch of the whine. High pitch won't be gearbox input shaft bearing nor clutch release, as there is no difference when changing gear.
tony9, Dec 11, 1:59pm
They are know for a whine at above 300Kph.
mohaka, Dec 12, 4:22pm
Also
"thumping sound which increases higher the speed and decreases"
-a mount gone?
poppy62, Dec 12, 4:57pm
Another thought that would account for the whine and thumping is the support bearing on the long drive axle that is usually bolted to the block. Assuming that the mazda demio has this arrangement.
bashfulbro, Dec 12, 5:16pm
Is your wife a pom ?
marte, Dec 12, 5:48pm
My cars got a whine, I know its the power steering belt or something as the brackets shifted and the belts at a angle on the unit.

And the speakers has some sort of interference, probably from the alternator suspressor.

Tap tap tap from the valve area that comes and goes, dunno why, feels like too much gap.
zmnewzealand, Dec 14, 6:30pm
not timing belt tenisoner as is regardless of engine rpm or load and timing belt was replaced about 2 months ago and the tensioner seems to rattle not whine like this. you have sit stationary and hold the rpms steady at a high rpm and the sound doesn't exist only when the car is in motion. checked the tires for any abnormal wear and all look good and there's no play in the wheels at all( vertical or horizontal) i did notice it sounded like the sound came from the centre of the car( sitting on the driver side) which happens to be close to where the output of the gearbox is. I will get a mechanic to have a better look when i have some spare time.
zmnewzealand, Dec 14, 7:01pm
update took it for another little drive after being told to try in gear or coasting which made no difference and also to load the bearings by turning left and right which seemed to have no noticeable difference I however now believe the sounds coming from the right hand side of the car. no noticeable shudder/wobble in the steering wheel. kind of sounds like a low groan mixed with a helicopter at higher speeds.
snoopy221, Dec 14, 7:10pm
kind of sounds like a low groan mixed with a helicopter at higher speeds.

She all points to wheel bearing .
When you did this tyre play check. didja.
Think about spinning the wheel by hand and LISTENING?-Presumtion here is vehicle WAS jacked up-NEEDS TO BE. and wheels were off ground.
Even with a standard vehicle jack lifting one side at front and jumping in there and starting engine and engaging second gear and say 1500 rpm and repeat procedure for other side is simple pretty safe basics.
Reckon one side up will be noisy other won't. K
franc123, Dec 14, 7:15pm
Touching the strut or spring while doing the above test will confirm, if its that bad you will be able to feel it through those parts as well as hear. I'd also make sure there isn't any excess run out in the tyre or any weird wear patterns, its surprising the racket those issues can make.
mm12345, Dec 14, 7:54pm
One more suggestion:
Jack it up, take the wheel off on that side, and check that the splash-guard behind the brake rotor hasn't been bent so it's touching the disk.
Just as guess, but I've done this myself accidentally when working on FWD cars like that - from needing to get something on to the front pulley nut (as would have been needed to do the cambelt), by accessing it from a removable panel inside the RH guard with the wheel off.
mm12345, Jun 19, 3:39am
^^^
Adding to that - if it's a top-hat disk, you'll probably need to put the wheel nuts on just tight enough to hold the disk on the hub, so you can turn the disk and hear/see what might be going on. If it is bent, just lever it back where it should be with a medium sized screwdriver.