Hey guys, lately I've been noticing an incredibly annoying high pitched whine when I'm driving around. It happens at about 60km/h at a modest volume (I originally thought It was just my new tyres/road noise) and will stick around as I slow down to about 40km/h. I won't notice it unless the stereo is off, usually.

It is also INCREDIBLY bad at about 90km/h. It sounds like a freakin' dog whistle, thats how pitched it is.

I changed the dif oil, and I'll be checking the wheel bearings tomorrow. Is this a common thing with the AWD's? I couldn't find many threads on it, other than the battery one, which I'll be checking tomorrow as well.

Any tips/suggestions?

Hey there mate.

It is common for the AWD's to have a very slight whine every now and then.
Found usually around 100-110km/h.
Where abouts is it comming from? Usually the rear diff that makes the noise.
Sounds great i recon but its only very slight, not like what you are describing.

How was the diff oil? You did it yourself? You confident you got it right?

Yes, I recall the diff whine in a company fleet TL AWD a few years ago.

It would happen most noticeably between 95-105km/h.

Notified Mitsubishi and they actually ordered an entire whole new diff assembly from Japan (waited 4 weeks) under warranty. How surprising......they just had to verify if the diff oil was replaced at 45,000km (which it apparently was), thus giving the green light for them to admit fault that the diff was 'faulty'.

Gee, thats not good. I have heard that these diff's are bulletproof.
Sounds strange.

Hey there mate.

It is common for the AWD's to have a very slight whine every now and then.
Found usually around 100-110km/h.
Where abouts is it comming from? Usually the rear diff that makes the noise.
Sounds great i recon but its only very slight, not like what you are describing.

How was the diff oil? You did it yourself? You confident you got it right?

I can't really pinpoint where its coming from, it just seems to come from behind the driver however.

This thing isn't slight, it's quite high pitched. I'll have to try and get a recording of it, and we'll see if its a similar sound.

I didn't do the dif oil myself, but when I put it in for a 125,000 service I got them (Mitsi) to do it.

I'm really stuck as to what to do at the moment..Its starting to worry me.

As i said, they all do it very slightly but usually round the 100km/h mark. You can barely hear it if the car is dead quiet inside.

DOn't stres to much mate. The diff wont fail you. Just the noise is annoying hey.

Had you done the diff oils before the 125,000?

I do the diff and transfer case every 40,000 with transmission flush. Saying that though, the oil is always like brand new when we change them.

I wouldn't have thought missing out on an oil change would make it whine.

Was it whining before Mitsub hanged the oil? I'm sure the grade of oil would be right if they did it.

You say you thought it was the tyres originally. What made you change your mind?

I might not have a AWD but my KJ2 GTV has done the exact same thing 3 times now. The sound I have pinpointed definately seems to be coming from behind the dash.
Everytime, its been at night, with over 1/2 tank of juice, and two adults and 3 kids, pram etc.
As far as I know the only similarity is the 5spd auto, whe did you have a flush done? Im in need of one myself.

Hope this gives ya more ideas, let me know if you find the prob please, I hate it!

Perhaps unrelated all together, but I'll throw some input.

My TH is making a whining sound not unlike a (much quieter) supercharger. Volume constant, pitch varies with engine speed. Pitch increases until around 60km/h then unheard due to road noise. Been told it's likely my power steering pump, but haven't been stuffed to investigate and verify.

I had a flush done at the 125,000km service. Same time I had dif oils done. It was whining before that, but I'd always have the stereo cranked so I didn't notice that much.

Before that, I hadn't changed the dif oils. I've only had the car since 104,000kms.

The reason I changed my theory about tyres was that it sounds like its coming from the centre of the car (behind the driver, to the left)....not the tyres. Plus, I had new tyres put on recently (different tread) and the sound is still there.

I can only really notice it at 60km/h or 100km/h with the stereo off. Its louder than the road noise though. And at 90km, well, it sounds incredibly similar to a dog whistle. I'll grab a recording some time tomorrow and upload it.

First thing I did was check the gears. at 90k+ its there through 3rd, 4th and 5th, although its only just audible in 3rd. My first thought was a chip in the gears, but then I remembered the auto box. It wouldn't be caused by a crack in the the actual box or anything? If I knew more about it I'd probably try and have a look.

I think the fuel pump may be located near where your describing

Hey guys, lately I've been noticing an incredibly annoying high pitched whine when I'm driving around. It happens at about 60km/h at a modest volume (I originally thought It was just my new tyres/road noise) and will stick around as I slow down to about 40km/h. I won't notice it unless the stereo is off, usually.

It is also INCREDIBLY bad at about 90km/h. It sounds like a freakin' dog whistle, thats how pitched it is.

Any tips/suggestions?



Can also be wind noise if your door seals are not perfect or your window is not sealing properly with the frameless windows. First check that all you windows are fully wound up, a simple 0.25 - 0.5 mm gap could cause that sort of whine especially as it is speed dependant and gets worse with speed. If that doesn't work have someone travel with you and when it occurs try pressing each of the the windows against the seals and see if that affects it.

Throw some sawdust in the diff. That'll stop the whine :-) !! Used to be what the dodgy used car dealers did where I was growing up!! Seriously though. Change of diff fluid & you might want to ckeck out tailshaft slap.

front diff usually first to go.. could be that... its very hard to fill the front diff/transfer case and alot of time ppl think its full when its not (ie wont seem to take anymore fluid, so they think its full.. but you have to wait a bit a keep putting more in).. it only holds 600ml so its easy to under fill it and usually results in noise as youve described followed by a BANG and goodbye front diff

has the car been generally driven hard in its life?

i have doubts its the rear diff, unless its been filled with wrong oil or also under filled... they're a strong diff and your car isnt putting enough power through it to worry it i wouldnt think

Perhaps unrelated all together, but I'll throw some input.

My TH is making a whining sound not unlike a (much quieter) supercharger. Volume constant, pitch varies with engine speed. Pitch increases until around 60km/h then unheard due to road noise. Been told it's likely my power steering pump, but haven't been stuffed to investigate and verify.

Peter_Pan's is doing this, we believe it to be the water pump... Does it do it in a straight line?

You may want to open another thread for this one...

Just throwing it out there, any chance it's a speaker problem? I had a weird high pitched noise in my car that was directly linked to RPM, and it was a speaker.

Throw some sawdust in the diff. That'll stop the whine :-) !! Used to be what the dodgy used car dealers did where I was growing up!! Seriously though. Change of diff fluid & you might want to ckeck out tailshaft slap.

Rear diff whine seems to be a common problem with the AWD's. Mine also exhibits some rear whine at the 100-105kmh mark onn very light throttle. Never been thrashed BTW. I just put it down to age & inherent lack of driveline refinement that the AWD's exhibit compared the FWD's. I changed my diff fluid @ 45000ks but I didn't notice the whine until after putting on the 18x8's last December. Have you got the stock wheels on or some aftermarket ones?

Mine has a faint whine at around 90 kph....i've always assumed it was the diff, as thats why Mitsi added that block of steel thats attached to it. Its normal to have some whine with these.

I wouldn't call it a problem.
Any rwd has a slight whine in the diff, its just that people are not use to hearing it in a Magna/Verada.

Jump in a new commy or falcon and you will hear it as well.

I had a similar things years ago with a Skyline I had. Turned out it was the centre bearing in the tailshaft. Might be worth having a look at that.

bollie7

I had a similar things years ago with a Skyline I had. Turned out it was the centre bearing in the tailshaft. Might be worth having a look at that.

bollie7
ooh yeah me too! 3 times! notorious for it, ended up having a single piece shaft made.

Gee, thats not good. I have heard that these diff's are bulletproof.
Sounds strange.

Diff whine in itself isn't necessarily an indication of diff trouble. There are a lot of bits in the drivetrain that can vibrate and other bits that amplify the base noise so that it sounds worse than it is. Mitsubishi didn't have many $$$$ to develop the AWD so cut corners with NVH. The heavy block on the diff cover was an attempt to reduce vibration frequency/harmonics/resonance.

I've been in only 2 AWDs, mine and Graham's, and both have diff whine under light loads/coasting at around 90-110kph. Its more audible on certain types of tarmac. Under heavy acceleration I can't detect any noise, but then at my age I'm getting deaf too.

Typically diffs whine when there is generous gear backlash. More backlash is usually good for better diff life and bigger gear loadings. Less backlash is quieter but the gears get hotter and are more easily damaged by shock loads.

Cheers,
Alan

Common problem with AWD cars. I have a MPS 6, and whilst I've been lucky so far, a lot of guys on the Mazda forums complain. Mazda has had so many complaints that they categorise it as normal, because they have replaced diffs and then the noise comes back after a while anyway. I'd imagine it would be a similar issue with the AWD Magna.

My TL VR AWD recently developed a whine/hum coming from the back from about 30kph to 80kph but could not be heard at freeway speed. Had been getting louder and I thought Diff/rear wheel bearing, drive shafts etc.
However, a close examination of the rear tyres revealed a slight saw tooth kind of wear on both the inner and outer edges of the tyres, Bridgestone Grid 2's about one third worn.
So I swapped them around, front to rear, rears to front. Bingo the noise disappeared, now quiet as a mouse.
Anyone with similar noise problems don't discount noisy tyres creating a hum which can be confused with a noisy diff, etc.

Did you check your tyre pressures? low?

My TL VR AWD recently developed a whine/hum coming from the back from about 30kph to 80kph but could not be heard at freeway speed. Had been getting louder and I thought Diff/rear wheel bearing, drive shafts etc.
However, a close examination of the rear tyres revealed a slight saw tooth kind of wear on both the inner and outer edges of the tyres, Bridgestone Grid 2's about one third worn.
So I swapped them around, front to rear, rears to front. Bingo the noise disappeared, now quiet as a mouse.
Anyone with similar noise problems don't discount noisy tyres creating a hum which can be confused with a noisy diff, etc.

Sounds like you have a problem that caused the saw tooth wear and as Zero suggests most likely is low tyre pressure to get the same wear on both sides of the tyre unless it had occurred on one side akready before the previous tyre rotation. Have you checked the rear wheel toe in/out and have you got non standard wheel or tyre size and width which could have altered the rear wheel camber? That would usually affect one side of the tread at a time.

Unless you have changed anythng else it is likely the latest tyre rotation has just presented a new surface to wear the same as the previous and then the noise will return.

Car has standard wheels and tyres, front and rear run at 38psi, apart from the irregular wear on the edges of both rear tyres, dead even across the whole of the tread.
I think I read somewhere else on the forum that Grid 2's can get noisy when around half worn. Anyway at least I know it is not an expensive mechanical problem.
Car runs just fine quiet and smooth.

I had the same problem in my TW VRX AWD at around 90k. Started like a soft whine over 40kph then got louder as I drove faster. Noise level increased over a couple of weeks. Mitsu drained the oil in the transfer case and found metal shavings in it. Warranty covered it and a new transfer case was installed and it hasnt missed a beat since.

Hope this answers everyones problems.

I never had the noise - and I never had the wife -ergo you must be right

Car has standard wheels and tyres, front and rear run at 38psi, apart from the irregular wear on the edges of both rear tyres, dead even across the whole of the tread.
I think I read somewhere else on the forum that Grid 2's can get noisy when around half worn. Anyway at least I know it is not an expensive mechanical problem.
Car runs just fine quiet and smooth.

38 PSI seems high? I just got 4 new tires fitted (65,000k on first set). Stock Bridgestone Turanzas. I was running the old ones at 31PSI(213k) Which is the standard 1 person weight on the tyre plaque. min I think was 180k. The Tyre Guy insisted that I should be running them at 34PSI(234K). Since I got the new tires I have a hum/whine/drone right on 60k. It's a good speed indicator but I could do without it. To me the hum sounds vibration based and seem to resonate through the car, thus the noise. It's not loud, hard to hear if the radio is on.
Could it be the same thing ? I might try dropping 2 PSI out of the tyres and see if it changes.

One thing i have notice with the new tyres is that with an extra 5mm of tread my speedo is spot on with the gps at 60k. it used to be 3 ks slower.

just to add my 2c...

my TJ2 AWD Sports developed a horribly annoying whine in the back ... sounded just like a diff problem.
first set in at around 105kph.... then gradually got louder and down to lower speeds too (60kph+).

took it in for a service....the tyres (Bridgestone Potenzas) were quite worn.... and tyre guy noted he wouldnt recommend them as 'they have a reputation to drone'. So i got Pirelli G7's.... and tadaaaaaaaaaaah... no more whine straight away.

So in mine..... the diff problem type noise was most definately just worn bridgestone tyres.