I have had my car for about 2 and a half years and have replaced the engine mounts 4 times due to collapse under CPO extended warranty. They are ready to be replaced due to idle vibration for the 5th time. The car lives in a temperate climate with smooth roads and is only driven about 5500 miles per year. I have never had this problem on any other car including older S class. Was this a bad mount design or is this normal for the gel filled units to fail quickly and on a repeated basis? Is there an aftermarket solution that it better and more durable? I don't want to be replacing them every 3-5 months with such low engine run hours! This is crazy!

 

Repeated motor mount failures are not normal. They normally last 50,000 miles or more unless they are damaged by a collision or excessive speed over pot holes and speed bumps.
I would go to a different dealer. It is possible that when the mounts were replaced, they were improperly installed or damaged during the installation.

 

I forgot who told me/where I read that the gel based ones are indeed problematic and you should replace them with a model that is not gel based ... did I remember it right?

 

Dealer is claiming this is parts failure. I'm sick of wasting time fixing same issue repeated times.

 

I think dealers warranty their repairs for 1yr 12k miles.

 

Again, 5 times same failure, all covered under CPO extended but a total waste of my time to repair the exact same thing multiple times.

 

So I'm at 6 months later/2700 miles later and motor mounts have failed again.....time number 6 to replace in less than 3 years all dealer installed - all genuine parts. Nobody else in a hot climate is seeing this?

 

Defective parts, defective production run?

 

Describe why you think it's the engine mounts.

 

I live in Phoenix and it's still 108F here during the day. I replaced my mounts right after I bought the car in March of 2017 and 30k miles later still have the same mounts. So, something's not adding up here.

 

Any humming/droning noises, see attached bulletin.

 

We've pulled them out and put them on the bench to see the fluid has exploded, engine is rubbing on the frame vibrating into the cabin and the steering wheel. Replace them and problem is solved for about 6 months.

 

Hi, I had the problem with vibrations inside the cabin twice in less than a year.
I’ve got all the (3) engine + (1) transmission mounts changed. However they were changed at different time . So by the time they replaced the transmission mount probably the other ones were a bit affected already. Then replaced all of them. They explained to me they all are correlated so if you replace just one ,and you don’t replace the other probably that isn’t gonna fix the problem. On the other hand , when they finally replaced all of them, they noticed the previous shop installation wasn’t right . The transmission mount has some space in the screws area so it can be aligned. If the screwed are set to the left then the weight of the transmission will affect. It has to go right in the center of the screw hole.

Sorry my wording probably is not the most clear. I already spent 1400 USD in all this, I really want to help others avoiding this repeated issue.

see the image the screws or bolts to aligned to the left. That cause extra stress on the mount so it will fail again. Also affecting the other mounts.