Alright, so seeing so many mounts go bad, I'm wondering how much strength the broken mounts actually lose or do they mostly lose dampening ability. Considering the oem mount design, my guess is it is structurally fine without the oil bladder. Not saying a broken mount is ideal, but...any engineers willing to do a compression test? Can't imagine the oil bladder adds significant strength, but I've been wrong once or twice before.

Greg

 

Consider this, the mount goes bad because of severe stress from the engine rocking back and forth. Without any fluid, the range of motion may be increased a touch. So what? Well, this eventually transmits more stress to other components such as the header to Cat Flex joint. While nothing will appear to be different that stress over time will cause that flex joint to fail. Now you have an exhaust leak, a check engine light, a broken motor mount etc... Hopefully you don't crack the header itself.

This won't happen over night and if you don't drive aggressively, it might not ever happen. My guess is that there are thousands of MINI's driving around with a bad upper mounts.

I switched mine to Vibra Technics mount when the OEM mount went bad. It's costly, causes more NVH but I will never have to replace it.

 

Biggest issue with the broken (leaking) upper mount is ENGINE MOVEMENT, and lack of damping....your engine is dancing like crazy..stressing tons of stuff...
Remember that a few folks experimented with adding urethane to the failed oem mount for a few years like Honda folks did....heck..bet that was the inspiration for the TSW one...
A failed mount makes it hard to drive smoothly....but also stress the tranny mounts and clutch...
For about $180 installed (a new oem one is cheapest )...about $90-100 parts plus install, but you can get the TSW urethane one....or go for the $$$ and get a $350 import that folks seem to love...
One thing that can be done...
TSW, and VIP still sell a "dogbone" style stiffener that helps to limit the engine moment... Way still sells it with new lower engine mounts....the reduced engine movement seems to help the stock mount lasts a bit longer.... But heck...if you learn to diy the oem...it is still a $100 part every 30,000-50,000 miles....

 

^This^

In a nutshell.

 

Replace it with a Vibratechnics and be done with it....or have fun replacing the stock one every 30k, for the reasons listed above