General: engine mounts

[hodge911]

new to the volvo marque as of last oct can someone please explain why the front engine mount on my 2005 xc90 d5 automatic has vacuum pipe to it
thanks in advance

[cheshired5]

The rear mount is vacuum operated too.
Vacuum is applied up to 1000 rpm to soften the mounts to reduce engine vibration then the mounts harden up over 1000 rpm when less damping is needed.

[hodge911]

Originally Posted by cheshired5

The rear mount is vacuum operated too.
Vacuum is applied up to 1000 rpm to soften the mounts to reduce engine vibration then the mounts harden up over 1000 rpm when less damping is needed.

so what symptoms do you get if they go wrong ?

[cheshired5]

Originally Posted by hodge911

so what symptoms do you get if they go wrong ?

The symptoms of bad vacuum mounts could just as easily be many other things. The symptom range also depends on whether you have a Euro 3 or 4 D5 so if you suspect you have defective mounts, just test them with a vacuum tester which will give a definitive answer in minutes.
Diagnosing them via symptoms is a fast way to nowhere.

[SwissXC90]

Originally Posted by hodge911

so what symptoms do you get if they go wrong ?

The vacuum mounts are designed to reduce vibration at low speeds.
If faulty, your symptoms may be:

• broken engine mount
• excessive engine vibration
• oil leak from mounts
• or all or none of the above