Author Topic: How do stock motor mounts fail? (Read 2538 times)

76m2002 · « **on:** May 03, 2012, 09:45:20 AM »

Our '91 318is seems to have a lot more rpm-related chassis vibration than before, it feels similar to when I put urethane motor mounts in another car. Can motor mounts stiffen up with age, rather than breaking? There is no engine rock visible.

Geoff · « **Reply #1 on:** May 03, 2012, 11:35:34 AM »

the stock motor mounts are hydraulic. I dont know for sure, but I would guess that when they go bad, the cushion effect is no longer working and the mounts are reduced to just banging up and down with the engine.
Geoff

thedguy · « **Reply #2 on:** May 06, 2012, 07:27:59 PM »

They tear and cause the fluid to come out. The engine moves more and is most noticeable by bucking or harsh driveline lash when getting on and off throttle.

I replaced mine with some at rock auto and was well worth it.

PeabnutBubber · « **Reply #3 on:** May 26, 2012, 04:14:38 PM »

Interesting, I've felt a lot of movement coming from the engine and such and I never thought to check the mounts. Would I be able to notice the decay by looking at them?