I've got a strange issue with an XC90 (2004 T6). I'd been hearing a strange crunching sound come from what I thought was the front suspension. It was very pronounced at slower speeds, slightly when turning, very noticeable when traveling over the slightest bumps, and even when simply backing out of the driveway and rolling backwards over the curb.

I had it checked out at the dealer, they could find nothing wrong (after several attempts). After a while, I just couldn't take it anymore so I went on a hunt to determine the root of the noise myself. Turns out the strange crunching/rattle was coming from a boot (not sure the exact name of the part) that goes around the steering column/shaft and attaches to the firewall. This boot has a clamp that clasps on to a small flange in the firewall. I assume this part is there to prevent engine noise and the elements from getting in to the passenger compartment.

This boot had popped loose from the firewall and was creating the noise. Sounds simple and strange, but it is true. I reattached the boot with the clamp to the firewall, and voila, the noise was gone. Problem is, the boot keeps coming off the firewall. So the noise keeps coming back.

The flange on the firewall doesn't seem to have much surface area for the clamp to grab. So it keeps popping off. Perhaps the rubber material in the boot has deteriorated and made to boot less pliable. I don't know?

This gets me to my question, does anyone have a solution for keeping this boot attached to the firewall?

Cheers!

 

Have not run across it yet I would have to wait till one came in at work and look at it.

 

Where is this boot located? Do you access it via the open hood, or the interior?
I also have a creaking 'pop' sound audible at slow speed/stationary turning. Dealer tried 'fixing' it, but I still hear it.

Can you explain how I can locate this boot, so I can check it out?

Thanks

 

It is located in the interior. It's in between and behind the brake and and gas pedal arms.

Here are a couple shots:
This is the boot in place-


This is the boot with it's outer sheathing lifted up-


This shows the clamp with the sheathing lifted up-


Move the driver's seat all the way back to gain access. Pull back some of the flooring around the boot (you should be able to pull back enough that isn't glued down to the floor board). It's a one piece boot that has an inner sheath that clamps to the firewall and an outer sheath that covers over the inner sheath and clamp. When I first looked at mine, it appeared normal. But upon closer inspection, I could see it was out of place. And once I lifted the outer sheath, it was obvious the entire boot had popped loose of the small firewall flange.

 

One thing to try once the boot is on place is spray the metal bushing you see on the shaft with spray silicon. Basically spray between the boot and sleeve and see if it will stay connected longer.

 

tech-

It's funny you mentioned that. That is exactly what I did yesterday after taking the photos. I'm still waiting to see if it will make a difference. Chances are hopefully pretty good though.