XC90 - Vibration while in drive but car at rest

[jonny_temperance]

I recently purchased a new 2011 xc90 two weeks ago. The car seems great with the exception of an annoying vibration that occurs only when the car is in "drive" but at rest (like at a red light, stop sign, waiting to make a left, etc.). The vibration is a low frequency drone. If I put the car in neutral, it is fine. If the car starts to move, it is fine. It is only when the car is in gear and not moving. When I took it in, the service guys heard it and checked the mounts, which seemed to be fine and they felt everything was normal. We also drove another xc90 on the lot to compare and it seemed to have the same issue, but not as loud. It seemed better when I drove it off the lot, but now seems to be incredibly loud again. Normally, I am not one that has an ability to even hear vibrations and think I have a pretty high tolerance for this stuff, but this vibration seems so incredibly obnoxious, i find myself cranking the radio to drown it out. has anyone else run into this? The service guys seem to think everything is fine, so if someone has run into this and knows the remedy, please let me know, so I can counsel my local dealership who seem to not know how to fix it. Thanks!

[cattlecar]

I have felt that drone in volvos with the 3.2 I6.
I think it will have to be something you push a bit. The idle speed is in the resonant frequency range for the combination of that engine and the exhaust.
The idle speed is variable and changes with ambient temp so it can be OK until temp reaches 35C/86F where the ECM picks it up 50-75 RPM and it hits the drone zone.
The idle speed can't be changed by dealer.
Manufacturer assistance via an escalation is what it will take. Squeaky wheels get the grease.
I bet you will find the drone goes away if you very gently depress throttle to get RPM up just a bit.

[Fuquay- Volvo]

I am experiencing the same frustration. We bought a 2009 XC90 with 20,000 miles on it a few months ago and soon noticed the high vibration levels when stopped in gear. We have now had two different rear seat passengers (kids) comment on how bad it is. The dealer has stated numerous times that it is normal.

I do a bit of vibration measurement at my work, so I took my measurement instruments and did some comparisons. I compared it to a friend's 2007 xc90 and noted that the frame vibration levels were about twice as high on the 2009. Also at the time, the 2007 engine was running at 650 rpm, compared to 750 rpm on mine. (I've since noticed that mine will run between 600 and 800 rpm depending on temperature.) But when I gave some gas to the 2007 and increased speed to 750 rpm, the vibration level only increased 5 or 10%-- it was still nearly half of mine.

I was having some other work done at the dealer and he gave me a loaner 2010XC90 to try out. I took the same measurement on it, and got the same vibration level as my 2009. And it felt the same. : (

I've tried to find more information on the engine mounting system. The engine mount information I can find on-line indicates that the main engine mounts are vacuum controlled- meaning that they can change their stiffness to respond to different engine speeds. I can find no vacuum lines going to my engine mounts (I assume I should be able to see some lines going to the mounts), so I wonder if the design changed for 2009 and beyond to eliminate the vacuum style mounts? Does anyone know?

How do we go about escalating this? I haven't seen much chatter about it on-line, and it's bad enough that, if this is indeed common, I can't believe more people are not completely annoyed by it.

[OPlo]

copy and pasted from johnny_temperanace's post on volvo-forum...

We have the exact same issue with our 2008. Had I written a post myself it would have followed yours nearly word-for-word. Juts as you say - stopped and in gear. We've noticed it worse on an incline. Have had it in to two different dealers with the same result as you. Nothing wrong. On the last trip I thought they had it fixed. They found the lower torque bar was off-center. No vibration when I drove it home through city traffic. But now it's back and worse that ever - especially in the back seat.

One confounding thing is that it's inconsistent. It doesn't ALWAYS happen to so the techs may drive and either:
A. Not notice a thing - OR (worse) -
B. That's just how these cars run and they see nothing wrong - But I REFUSE to believe that a 40K car should shake like this.

Theory of from my mechanical wiz father-in-law:
The exhaust runs right under the cabin and is transferring vibration upwards through the heat shield. Couple proposed solutions if this is it:

a. Replace the relatively nonrestrictive muffler with one that is more restrictive. You may loose a couple horsepower but the vibration when the engine is pulling should be lessened.

b. Put a piece of heat insulation sheet between the heat shield and the cabin (http://macsautoparts.com/1960-72-for...0IBZVU1000007/). This stuff is sticky on one side.

One test he recommended is to put the car in neutral and turn on and off the A/C. This puts more pull on the engine. If you are feeling the same vibration, it is likely the exhaust.

My father-n-law also mentioned the idle speed at one time. He thought it needed to be increased. So the goal is to INCREASE or DECREASE the idle speed to what?

[Fuquay- Volvo]

I spent lunch today measuring vibration on the loaner car I mentioned above (the 2010 XC90). The measurement device has a magnetic base so I stuck it out the driver's window on the front left corner of the roof. I found a couple interesting things:

1) The vibration increases with load on the engine.

While the engine was idling at about 750 rpm, here were my measurements:

In park, with A/C off: 5 mili-G's (Felt very smooth)
In park, with A/C on: 15 mili-G's (Felt it, but not too bad)
In drive, with A/C off: 15 mili-G's (Felt it, but not too bad)
In drive, with A/C on: 32 mili-G's (Felt rough)

The rpm maintained roughly 750 rpm through all of this.



2) Also interesting is the relationship with engine speed. This morning, the car was idling at about 650 rpm. (engine RPM seems to have more to do with the air temp than the engine temp).

In park with AC on, 650 rpm: 15 mili-G's
I gave it a little gas with my foot on the brake. Vibrations steadily increased until the engine hit 800 rpm (@ 65 mili-G's - very rough!), then began to decrease as the engine speed went higher.


So you can see the variable nature of this vibration.... depending on what speed the engine wants to run... and if AC is on or not... a dealer may or may not experience the worst of the vibration.

Have others noticed similar behavior?

[OPlo]

Good testing. I'm printing this out and taking it with me when I go back to dealer #2 - again - tomorrow afternoon. This gives my some ammo and additional ways to replicate the problem with the tech in the car.

[OPlo]

Bad news. Took our XC90 to the dealer again today with this information in hand. Had the tech sit in the car with us to experience the drone. He heard it/felt it with us - confirmation that it exists.

He then went and checked 2 other xc90s with the 3.2L on the lot - same thing. Nothing they can do. This is "normal" according to them.

I truly believe there is a design/engineering flaw. I've contacted Volvo USA. We'll see what how/if they respond.

Don't really want the car any more. May get rid of it if this can't be solved.

[Volvophile]

Our XC90 is the 2.5 and has a "dog bone" anti-torque mount up top in the back. If is wears out(like ours did) it will vibrate fairly violently in drive and more than normal in park. Reverse too, of course.
It is located in the rear right hand side and I do not know, but assume you have one too? Check it because it is cheap ($30.00). Our front one was shot at 50,000. It is not solid, it is just like the rubber bushings on the suspension (which go bad too soon also).
Good luck. Hopefully it is a simple fix!

[Volvophile]

FYI: My Wife's xc90 had a loose steering wheel at 36,000 miles. Kinda scary with an air bag and all.......I called a GREAT Volvo dealer in Las Vegas (who gave me free radio codes when all others wanted $50.00) and told them about the problem. They said to bring it in to them and they would work on it but it would cost me.......2 "thingys" on the back allow the horn/airbag to come off(take off negative/ground FIRST if ya don't want a face-full of screwdriver--airbag, ya know), anyway....I tightened the nut without even having to take off the clip...never had a problem again. I even mentioned that the loose wheel was a safety hazzard (read---filthy lawyer-sue-you-if-we-die) but they would not budge

[Fuquay- Volvo]

OPIo - Sorry to hear about your experience at the dealer. Thats been my experience too. I think that all XC90s show this vibration to some extent-- some may be worse than others. But because of the variable nature of this behavior and the fact that Volvo's official position is that "this is not a problem" -- I think it's going to take a lot of complaining to get the dealer to try anything.

I've taken some more measurements on my own car, in addition to the measurements on the loaner vehicle I had. In general my vehicle seems to act like the loaner, but I have measured it at a higher level more often. Where I measured 30 mili-G's @ 750 rpm on the loaner, I measure 42 on my car.

Other than load on the engine (i.e. in gear and AC on), the idle speed is the biggest factor. The vibration level more than doubles between 650 and 750 rpm. I wish there was a way to force the idle speed to be 650 consistently. Seems like that would make the problem much more bearable. The dealer says he can't change it since it is mandated by emissions.


Volvophile -- I'll take a look at the anti-torque mount. Did you change this yourself?