drone noise ?

[cpu_man]

Originally Posted by john langrick

Hi, just how noisy if your drive train.

Mine xc90 is much older than yours, and a lot more miles (170k), but if I listen very carefully I can also hear a very slight drone noise. This happened before and after my awd was fixed (spline gear and transfer box).

I can only hear it if the radio is off and the noise does match your symptoms.

But I know the noise is no more/Les than I hear on friends other makes of 4wd or and. So I just take it as part of the 'engine/ drive train noise

My point being, are you being a bit critical?, perhaps some noise is normal.

Cheers john l'

I did think this my self as I am very fussy with noises etc.

This I am still sure it's not ment to he there, the drone noise is not so much loud but it's a a noise level where I can still hear it with the radio on but that's more because I know the noise is there.

I can't see this being a normal noise in my eyes?

I can't see it being the AWD system as well as at 60mph on a straight A road I should be in FWD as the prop shaft would be spinning but the Haldex unit would not be engaged etc (I don't thimk) but I am sure the noise is from the back.

So if the noise is from the back but only on very light load (light foot on gas) but on FWD what can it be??

[cpu_man]

Originally Posted by trumpetdropper

Hi Guys

Looks like I might be experiencing a similar problem with my 05 T6 (@90k)
slight droning noise between 50 & 70 whilst under positive throttle.
Started a couple of weeks ago - new tyres fitted & tracked about six months ago so not ready for a change.
Immediate thought was wheel bearing but couldn't feel/hear anything when rotating etc each wheel.
Slight prickle about the gearbox, but all gears work and change smoothly (did a partial fluid change about 9 months ago - preventative measure)
Did wonder about the haldex and plan to do a service on this over the holidays if the weather is reasonable, and will check prop at same time.
I did notice this morning there is now a very slight vibration that can be felt through the floor especially where my left foot rests - might indicate something more centrally located?
I shall watch this thread with interest.

Cheers with seasons greetings to you & yours

Andy

I get no vibration or any thing like that with mine, very smooth when driven like a little old lady or when you put your foot down.

[cpu_man]

Hi guys, still trying to get to the bottom of this?

I have been under the car and every thing looks good with no sign of any thing causing the noise.

Still trying to work out if the AWD system on the xc90 would be in use at 60mph on the road or not?

Noise only happens at 60 mph (So road wheel speed related and not engine speed) ONLY with light throttle. If the AWD system is not in use at that speed how can i get a load noise at rear if nothing is being commanded to drive?

I came across this link from ebay, if you read the Description it does sound like my issie (I think), any one else know of this issue or any one else tried there xc90 at 60mph to see if they get a fain't drone with only light throttle?

https://rover.ebay.com/rover/0/0/0?m...2F132506504680

I have also come across this video:

https://youtu.be/fIDXymxFnKk

[gmonag]

The noise might not be at the rear after all. The sound can move! I had a knocking which I was convinced was in the front right corner and turned out be the silencer contactacting the rear floor due to a broken hanger bracket.

The only sure way to find it is to use Chassis Ears or similar.

[cpu_man]

Ok guys think I am getting closer to this noise issue.

Today I found some time to have a good look towards the noise in question.

So car in the air with the ABS disabled and in 3rd gear I was under the car while all x4 wheels are spinning, I can hear a rough noise from the front of the diff/hadlex area, I brought the car up to 60mph ( some on in car while I under car, don't worry car fully secured first) and the noise at 60mph from the front of the diff/hadlex area is very bad, so bad it transmitted though the prop shaft, it sounds like if you were to drag a screw driver across a half shaft while it spinning, it's that sort of bearing sound I think.

Now all the researching I have been doing it would seem the nose bearing in the diff are fragile and can cause this issue, I am thinking this COULD be my issue.

Very hard to tell if it's hadlex bearing issue or diff noise issue?

Do hadlex units have bearing problems?

Any guides on removing rear diff, is it a subframe off job?

[cpu_man]

Hi guys, so as per above I need to try and tell if it's my diff at fault or my hadlex causing this noise.

Is there a way to tell?

[nu11eaf]

I was driving passed Heathrow airport yesterday and I heard a Drone noise, it stopped after I passed the airport.

[minstrelblue]

My 2009 has recently started a low drone noise on tick and on acceleration goes away. It sometimes resonates at speed when accelerating but when you ease off it stops.I suspected an exhaust issue or loose heatshield. I took it into a garage and they diagnosed sagging front end exhaust rubbers and they showed me it vibrating. They said they are hard to get at and needs dropping the exhaust to get to them but said theyre intact and best left alone until a replacement exhaust is needed.