How do you know when your motor mounts are bad?

[Robert's_BMW]

How do you know when your motor mounts are bad? I’ve had the car for a few years and haven’t noticed any difference in NVH but I’m doing my rod bearings soon and I noticed a lot of people change out the motor mounts as well. I managed to take a picture of mine. Do these look bad? Should I just change them out?

[Tbonem3]

blip the throttle a little, does the engine rock quite a bit?

You can also just decide to change them out if they're old and/or have like 60k+

[beefaroni]

Most of the time that I want to replace a part, even if it isnt showing tell-tale signs of needing replacement, I feel a nice improvement and my mind is at ease knowing I should be good for the next ____ miles.

Rubber degrades over time. I'm sure if you replace them you will feel an improvement.

[COVID-19]

Sometimes the fan is close to hitting the shroud or the front of the oil pan close to hitting the sway bar. Other than that whatever ^ everyone else said.

[Robert's_BMW]

Thanks guys, I’ll probably just replace them. I don’t think they are bad so it’s more for peace of mind for the future.

[heinzboehmer]

I don’t think they are bad so it’s more for peace of mind for the future.

Worth replacing just for this reason alone. Plus, they're much easier to replace when doing bearings since you'll have the subframe off.

[jk715]

Didn’t notice anything when driving. But saw cracks when under the car. New vs old. If original at 175k miles.

[sbay]

Constant vibration when idling. Sometimes even when driving. When I turned the engine off I would get a good amount of vibration in the cabin too. Mine were toast when removed.

[Arith2]

If I saw those in a customers car, I would suggest them be replaced. The dry rotting will only get worse. BMW has good engine mounts, but why wait for the failure to come? Those are probably originals.