Rumbling sound/sensation under driver footwell -- 2007 S60

thebigsee · Post by **thebigsee** » 18 Apr 2016, 10:03

Bought my 2007 2.5T S60 with 45,000 miles on it almost 5 years ago. Quickly noticed a soft but consistent rumbling sound and sensation under driver footwell. Mechanic dismissed it, saying "That's just Volvo's, they're quirky like that, don't worry about it." Then I drove in my friend's 2007 S60 and his car does NOT do it so something is wrong.I read that it could be the wheel bearing so I replaced them but it didn't go away. Car drives fine and it didn't get worse so I learned to live with it.

Six months ago I replaced all the tires and thought, "Maybe this will fix that rumbling sound" but no. Then I had to replace the strut mounts and I figured "surely this will fix it" but no, and since then the rumbling seems to be a bit worse -- it almost feels like something is out-of-balance or like I'm driving on a flat tire, only much smoother of course.

Only things left I can think it is is A) CV boot/axle -- but it looks great, no tears or sign of rubbing or wear anywhere; B) Lower control arm -- bushings are a bit worn but intact; or C) A motor or transmission mount.

Any ideas? I am now preparing to replace the car so I either want to fix this so it isn't an issue with the buyer or at least tell them what it is. Thanks.

zanzabar · Post by **zanzabar** » 18 Apr 2016, 10:59

For A) get the car up on ramps with front wheels under load and shake the axles around and feel for play. I agree with you it doesn't seem that likely for these to be causing your rumbling, but if they are bad you should be able to feel play.

B) With car in P and engine off on flat ground and no parking brake, get a good view of the bushings and roll the car back and forth gently (it will take some strength to do this) and look for how much play there is in the bushings as the wheels stop rolling because the trans holds them steady but the car still rocks. You'll get a feel for how bad they are by doing this. It might be the cause of your rumbling but I think it is more likely to create a knocking sound when you go over small bumps.

C) Definite possibility, check them all, especially the transmission torque mount which is the one in the middle at the rear of the engine.

Is the rumbling sounds speed dependent? Could it be air causing one of the plastic wheel well or under engine covers to vibrate? Could it be one of the belts or pulleys rubbing against something?

thebigsee · Post by **thebigsee** » 18 Apr 2016, 11:24

zanzabar wrote:Is the rumbling sounds speed dependent? Could it be air causing one of the plastic wheel well or under engine covers to vibrate? Could it be one of the belts or pulleys rubbing against something?

Thanks so much for the advice, I will do everything you suggested and see. Funny thing is I took it to a very respected Volvo specialist last year for turbo work and he looked everything over and found several issues and even drove it for a couple days but never mentioned the rumbling. I figured it was normal until I drove my friend's S60 a couple months ago.

The sound is somewhat speed-dependent but it sounds/feels pretty much the same whether it's 40-70 mph, it's not like it's crazy whining or heavy vibration at freeway speeds. Could be something is being affected by air but I don't seen anything loose. Belts and pulleys seem fine. Overall I don't see any strange wear or rubbing anywhere. I had the struts out last week and everything looked ship-shape, nothing torn or worn-down or polished from rubbing at all.

MarcM · Post by **MarcM** » 18 Apr 2016, 16:43

Same issue on my '05 S60 (152k mi now). Thought it was because of the broken tab on the splash pan under my foot was wedged by broken piece and a washer. New pan installed Saturday, same song after driving it 60mi round trip today. It *USED* to be worse, so I think it may have been partially to blame. Before I replace the control arm bushings, I'm going to follow zanzabar's suggestions.

thebigsee · Post by **thebigsee** » 18 Apr 2016, 18:08

MarcM wrote:Same issue on my '05 S60 (152k mi now). Thought it was because of the broken tab on the splash pan under my foot was wedged by broken piece and a washer. New pan installed Saturday, same song after driving it 60mi round trip today. It *USED* to be worse, so I think it may have been partially to blame. Before I replace the control arm bushings, I'm going to follow zanzabar's suggestions.

Great, report back if you find anything, I will do the same.

thebigsee · Post by **thebigsee** » 19 Apr 2016, 09:44

zanzabar wrote:For A) get the car up on ramps with front wheels under load and shake the axles around and feel for play. I agree with you it doesn't seem that likely for these to be causing your rumbling, but if they are bad you should be able to feel play.

B) With car in P and engine off on flat ground and no parking brake, get a good view of the bushings and roll the car back and forth gently (it will take some strength to do this) and look for how much play there is in the bushings as the wheels stop rolling because the trans holds them steady but the car still rocks. You'll get a feel for how bad they are by doing this. It might be the cause of your rumbling but I think it is more likely to create a knocking sound when you go over small bumps.

C) Definite possibility, check them all, especially the transmission torque mount which is the one in the middle at the rear of the engine.

Is the rumbling sounds speed dependent? Could it be air causing one of the plastic wheel well or under engine covers to vibrate? Could it be one of the belts or pulleys rubbing against something?

Update: I don't have ramps to check suggestion "A", but I did the roll test for suggestion "B" and didn't see anything strange, but it did make a clicking sound. I think at this point I have nothing to lose to go by a local Volvo specialist and get their expert opinion -- if I can fix it I'm happy to pay them for the diagnosis. I'll report back whatever I find out next week.

zanzabar · Post by **zanzabar** » 21 Apr 2016, 11:42

I've heard that clicking sound (assuming it's the same, on mine it's a loud quick snap noise) on the roll test as well. I never was able to figure out exactly where it was coming from but on my car I suspect loose control arm bushings. I can distinctly see the bushings give way and the metal parts contact each other which is what I think makes the rumbling/knocking/clicking noises.

Post by **JRL** » 21 Apr 2016, 21:18

Did you check the front (right side of car) MOTOR MOUNT?

thebigsee · Post by **thebigsee** » 25 Apr 2016, 09:26

Original poster here -- took my car in to a Volvo specialist and it was the left-front wheel bearing. Makes sense but the only reason I did not expect it was because I replaced both front wheel bearings at about 45,000 miles (car now has about 82,000 miles on it). Noise is now 100% gone.

So, don't be surprised if your wheel bearings fail early/multiple times on your Volvo. I've been driving for almost 30 years and have had cars go well past 150,000 miles and never even had to think about bearings until I bought this Volvo.

Post by **abscate** » 26 Apr 2016, 08:29

Someone either used crappy parts or they damaged the bearing putting it in. The bearings on these cars are massive FAG and last 150k or more if they are OEM. I had one go at 150k and one at 175k and I was the earliest failure until your post.