D5 engine droning/booming under 60-80 mph

[Tannaton]

TITLE should have read BETWEEN 60-80 mph!

2003 D5 XC90 Auto with 140k on the clock. Have a problem with significant increase in engine noise/drone in the cabin between 60 and 80 mph. The noise is proportional to throttle, at full throttle there is vibration on the steering wheel as well. Interestingly it kicks in and is only apparent when the torque converter is locked. I don't think it is the gearbox though as I've changed the gearbox and torque converter since I got the car and it's made no difference.

Having searched the forum I've checked that both front and rear engine mounts are holding vacuum - which they seem to be.

I'm assuming it is probably engine mount related, the vibration on the steering wheel suggests it's on the subframe?

Any suggestions would be appreciated.......

[familyman2]

Hi there I am having the same exact same symptoms, after inspecting the rear mount which seems too be replaced by previous owner I noticed that the lower mount was shot! replaced it with a upgraded poly mount now it is even worse than before! Now it vibrates on idle too and all through the gears and at all speeds! I am interested in any responses that could solve these issues many thanks.

[Ducklakeview]

Originally Posted by familyman2

Hi there I am having the same exact same symptoms, after inspecting the rear mount which seems too be replaced by previous owner I noticed that the lower mount was shot! replaced it with a upgraded poly mount now it is even worse than before! Now it vibrates on idle too and all through the gears and at all speeds! I am interested in any responses that could solve these issues many thanks.

A poly engine mount is always going to be noisier than a factory one..

Mike

[Tannaton]

Now fixed!

I took off the gearbox torque mount, I had a good second hand one kicking around that came with a gearbox so i thought I would try that. When I took it off I noticed that the one on the car was solid, the one I was fitting had a rubber bush within another runner bush and about 5-10mm of free play in it. Much quieter now when the TC locks and substantially reduced vibration at tickover....

I'm assuming that somehow a mounting from a petrol engine has got on to the car?

[cheshired5]

Originally Posted by Tannaton

Now fixed!

I took off the gearbox torque mount, I had a good second hand one kicking around that came with a gearbox so i thought I would try that. When I took it off I noticed that the one on the car was solid, the one I was fitting had a rubber bush within another runner bush and about 5-10mm of free play in it. Much quieter now when the TC locks and substantially reduced vibration at tickover....

I'm assuming that somehow a mounting from a petrol engine has got on to the car?

Sounds like someone has previously fitted a poly bush but a photo of the offending mount would help.