New Motor mounts, how do I know if I need them?

[c good]

I was involved in a rear end accident. I was hit while stopped at a red light. Most of the damage was limited to the bumper cover, impact bar/trailer hitch, exhaust, and spare tire mount.
I now have a strange vibration upon start up that was never there before. Also a small vibration while at idle that was never there before. I have repaired the exhaust so this isn't part of the equation.

Anyways, I'm just wondering if the impact could have damaged the motor mounts, and if so, how do I test/check them? Thanks for any input.

 

[mrrsm]

If the mounts internal Elasto-Meric Fluid has leaked out of either one... you can spy the problem from underneath by looking for stuff that has the appearance of an ordinary oil residue patch... until you touch it and can see how sticky this stuff is by searching for what looks like patches of dirty grease, The stuff feels like sticky Gorilla Glue residue on contact with fingers. There may also be some areas adjacent the Motor Mount on the engine nacelle body where the stuff squirted, then shot out and spread around and stuck there looking like an ordinary oil residue patch. This link covers more information from other members with some tricks and Part Numbers to assist with how to do this R&R with less pain under your 4X4 chassis... hopefully while using only the right and proper OEM AC-Delco flavour Motor Mounts:

http://gmtnation.com/forums/threads...replacement-passenger-side.15720/#post-512182

 

[HARDTRAILZ]

Worth the read.

http://forums.offroadtb.com/viewtopic.php?f=26&t=970