Volvo Top engine mount - REBUILD?

I have an 05 XC90 with a cracked (rubber) upper engine mount.  Every review I read says the replacements, even the OEM mounts are really soft and most seem to fail quickly.  This is an "open" mount, with connections to the top and bottom, but the mount has air space to the front and back, to allow for some movement. 

I am considering filling the front and back cavities with a pliable, pourable material to stabilize the mount.  Thoughts on this concept?  Thoughts on a material to use?

Conversely, I can just change the mount out every 6 months to a few years, as that is what people are seeing.  The OEM is $75-$100 and the aftermarket are $25-$75.  A long lived fix would be great, but ongoing replacement would be OK too.

Thanks in advance,

Jack

The quick and dirty way is to fill it with 3M Window Weld, or alternatively stuff the voids with cut up pieces of steel tire belts. Polyurethane would probably be a more proper way to do it, given that some such voided mounts have poly inserts available for them.

The Volvo ones last 150,000 km.  Aftermarket way less.  Urethane bushings transfer a lot of noise in the 850, but the newer cars are better isolated from the body, so you could probably get away with it.

I personally hate the feel of filled motor mounts on a vehicle like this.  Destroys the ambience.  It's a luxury vehicle, not a buzzbox economy car, and it gets that status by a whole lot of little things like well-engineered mounts, rubber bushed subframes, resonance dampers, and the like.  If you start to chip away at that, you start sliding the thing towards being less than what it was.

If the mount hole is slotted like it is on the passenger cars, then install the mount as far preloaded under torque as possible (slide all the way forward), if you don't feel like ponying up for a new OEM mount.  That will at least keep your drivetrain angles happy and reduce stress on the mount under the radiator.   The "heavy lifting" is done by the three main drivetrain mounts (one under crank pulley, one under radiator, one on the steering rack) and that little torque mount is just there to make life easier on the under-radiator mount without having to make it so stiff that the vehicle buzzes and vibrates.

I lived with a poly mount in my 850 for about a year, but like Streetwiseguy says, it transferred a surprising amount of vibes, especially at stoplights, so much so that I got in the habit of putting it in neutral at every stop.  After about a year I went back to an OEM mount.

Lemforder is the OE supplier of most of Volvo's parts like that.  FCP or IPD will likely have a Lemforder mount, so you can buy blue box parts for way less than the blue box price.

Buy a box of flexi straws, buy 3m window weld and make your own filled mount but introduce the straws as vibration voids.

Id stick 1-2 cut up straws in the stock mount voids in certain locations to allow some give, then fill the rest of the mount solid with 3m window weld. This way you get some movement and vibration isolation yet its still stiffer than the stock worn out mount.

We did this on my old Elantra beater car and it worked out fantastic. The new Chump Car Elantra we are building is straight 3m window weld and the vibrations are extreme.

Thanks for the great ideas.  I like the straw spacers and window weld idea, as a solid bushing could be buzzy and it is a comfy cruiser, but may just price out a Lemforder from IPD for FCP.  Simple and quick, which will work for me. 

Work keeps putting me on the road and time has been quite precious lately.

Jack