AWD Transmission: - Resonance / noise at certain revs

Whizzer · Jan 2nd, 2016, 14:38

Hoping someone can help me here...
2009 XC90 SE Lux 185bhp D5 Geartronic 137k miles
I have just recently started getting a resonance (almost metallic noise) from what I believe is the 'front' drivetrain at certain rpm - so therefore not road speed sensitive.
The problem is particularly noticeable in 5th and 6th (in auto and manual) but can just be sensed in 4th. The resonance starts around 1800 rpm but tends to disappear around 2500rpm (or other noises overtake it!). I can make it come and go but only when 'cruising / under load'. If you accelerate relatively hard through the rev range you do not hear it and it seems all OK.
The engine and performance seem to be absolutely fine.
Having read many of the forum articles I have replaced front lower (vacuum) mount [this physically looked ok but was not holding vacuum as well as the rear mount) which I have not changed yet, the upper engine torque mount, and the lower gearbox torque mount.
Apart from improving gear changes none of these have solved the resonance problem.
I am now heading towards torque converter clutch / lock up issues as the resonance starting at around 1800rpm is similar to when lock up I believe occurs.
Any thoughts or knowledge would be appreciated. Thanks

GJB · Jan 2nd, 2016, 20:45

Have you looked at the possibility of a wheel bearing noise travels and it is well worth checking.

Whizzer · Jan 2nd, 2016, 21:10

Thanks GJB, I am fairly certain it's not a wheel bearing - as there is no obvious play in any of the wheels - have to admit it is difficult to check though.
I have also dropped into neutral when the resonance / noise is apparent and it disappears.
The noise starts at different road speeds depending which gear you are in - so again does not reflect wheel bearing issues.

GJB · Jan 3rd, 2016, 13:25

Suggest you look that this thread
http://www.volvoforums.org.uk/showth...=240791&page=2

Whizzer · Jan 3rd, 2016, 18:53

Thanks again....interesting and sounds similar (if not the same).
I am just wondering if the rear bottom vacuum mount has sagged too much. As mentioned earlier I have already changed the front lower and the two torque mounts - perhaps I should change the rear mount.
Do you know what the typical gap should be between the gearbox and the rubber stop on the subframe at the bottom. Mine is perhaps only 10mm or so?

Whizzer · Jan 18th, 2016, 22:29

Update - so I replaced the rear vacuum mount, the original did not appear badly worn and seemed to be holding a vacuum but was 5mm or so shorter than the new mount. The clearance between sub frame rubber stop and the gearbox perhaps increased by a little but still remains around 12mm or so.
At the same time I replaced my summer wheels / tyres and fitted my Winter Vreidstein Wintrac 4 Extremes.
Result is - the noise has gone!
What I am not sure about just yet is whether it was the engine mount, or the tyres (nb., the front tyres were recent Nokian Zline SUV) that had been the cause?

gmonag · Jan 22nd, 2016, 16:09

My money is on the tyres. I had one budget tyre on mine when I bought it and had a loud drone at various speeds. The dealer said I needed a new diff (£2300)!! I disagreed and changed the tyre - no noise anymore

Greg

AB-UK · Jan 22nd, 2016, 16:28

Tyres.
Just put on my winter set. Nice and quiet in comparison (more rubber 'twixt car and road surface)

Jan 2nd, 2016, 14:38	#1
Whizzer Junior Member Last Online: Apr 1st, 2024 17:46 Join Date: Jan 2015 Location: Maidstone	Resonance / noise at certain revs Hoping someone can help me here... 2009 XC90 SE Lux 185bhp D5 Geartronic 137k miles I have just recently started getting a resonance (almost metallic noise) from what I believe is the 'front' drivetrain at certain rpm - so therefore not road speed sensitive. The problem is particularly noticeable in 5th and 6th (in auto and manual) but can just be sensed in 4th. The resonance starts around 1800 rpm but tends to disappear around 2500rpm (or other noises overtake it!). I can make it come and go but only when 'cruising / under load'. If you accelerate relatively hard through the rev range you do not hear it and it seems all OK. The engine and performance seem to be absolutely fine. Having read many of the forum articles I have replaced front lower (vacuum) mount [this physically looked ok but was not holding vacuum as well as the rear mount) which I have not changed yet, the upper engine torque mount, and the lower gearbox torque mount. Apart from improving gear changes none of these have solved the resonance problem. I am now heading towards torque converter clutch / lock up issues as the resonance starting at around 1800rpm is similar to when lock up I believe occurs. Any thoughts or knowledge would be appreciated. Thanks

Jan 2nd, 2016, 20:45	#2
GJB Premier Member Last Online: Apr 22nd, 2024 15:54 Join Date: Dec 2004 Location: Cromer Norfolk	Have you looked at the possibility of a wheel bearing noise travels and it is well worth checking.

Jan 2nd, 2016, 21:10	#3
Whizzer Junior Member Last Online: Apr 1st, 2024 17:46 Join Date: Jan 2015 Location: Maidstone	Thanks GJB, I am fairly certain it's not a wheel bearing - as there is no obvious play in any of the wheels - have to admit it is difficult to check though. I have also dropped into neutral when the resonance / noise is apparent and it disappears. The noise starts at different road speeds depending which gear you are in - so again does not reflect wheel bearing issues.

Jan 3rd, 2016, 13:25	#4
GJB Premier Member Last Online: Apr 22nd, 2024 15:54 Join Date: Dec 2004 Location: Cromer Norfolk	Suggest you look that this thread http://www.volvoforums.org.uk/showth...=240791&page=2

Jan 3rd, 2016, 18:53	#5
Whizzer Junior Member Last Online: Apr 1st, 2024 17:46 Join Date: Jan 2015 Location: Maidstone	Thanks again....interesting and sounds similar (if not the same). I am just wondering if the rear bottom vacuum mount has sagged too much. As mentioned earlier I have already changed the front lower and the two torque mounts - perhaps I should change the rear mount. Do you know what the typical gap should be between the gearbox and the rubber stop on the subframe at the bottom. Mine is perhaps only 10mm or so?

Jan 18th, 2016, 22:29	#6
Whizzer Junior Member Last Online: Apr 1st, 2024 17:46 Join Date: Jan 2015 Location: Maidstone	Update - so I replaced the rear vacuum mount, the original did not appear badly worn and seemed to be holding a vacuum but was 5mm or so shorter than the new mount. The clearance between sub frame rubber stop and the gearbox perhaps increased by a little but still remains around 12mm or so. At the same time I replaced my summer wheels / tyres and fitted my Winter Vreidstein Wintrac 4 Extremes. Result is - the noise has gone! What I am not sure about just yet is whether it was the engine mount, or the tyres (nb., the front tyres were recent Nokian Zline SUV) that had been the cause?

Jan 22nd, 2016, 16:09	#7
gmonag Premier Member Last Online: Jan 15th, 2024 17:24 Join Date: Jun 2010 Location: Bury St Edmunds	My money is on the tyres. I had one budget tyre on mine when I bought it and had a loud drone at various speeds. The dealer said I needed a new diff (£2300)!! I disagreed and changed the tyre - no noise anymore Greg

Jan 22nd, 2016, 16:28	#8
AB-UK Premier Member Last Online: Today 08:26 Join Date: Jul 2007 Location: Nottingham	Tyres. Just put on my winter set. Nice and quiet in comparison (more rubber 'twixt car and road surface)

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