opto_isolator

So I was having issues with the Eco start causing slamming when the engine restarted. Dealer says bad motor mounts. Luckily it's covered under warranty, but how common is this? I can't believe it only has 42k miles on it and it's bad already? They are going to change out all mounts (motor and transmission), and said it would take 3 days to do so. Lucky they provide a loaner.

91senna

Sorry to kinda jacking this thread but I have questions regarding mounts.
Good thing you have warranty. I just got into a 2013 GL450 with 87k miles. Most warranty companies carried by my credit union/local dealer were in the $8-$10k range. Third parties were as cheap as $3k for 4 years of coverage but ya never know how they will back their claims.
I'm hoping someone can chime in with a DIY or an estimate for labor with motor mounts/ tranny mounts. My car runs fine but I notice a very slight grinding vibration on drivers side floor upon acceleration.

Thanks in advance

DaveW68

When I had my S600, the motor mounts were shot at around 30k miles....although they were around 9 years old at the time. They are liquid filled and electronically controlled, so you shouldn't be completely shocked by an early failure, especially if you live in an area that has cold winters and where they use lots of road salt.

opto_isolator

Yeah I noticed these appear to be actively controlled. They also cost about $200 each!! I don't think this is a DIY job - the dealer stated that you have to drop the subframe to get them out. If it takes them 3 days to do it, I doubt it would take a DIYer any less!! You probably also need to support the engine when the subframe is out. I would estimate that if this wasn't in warranty that it would be around $2-3000 to fix!

OldMerc94

I'm at 150k on a 2013 ML550 - my motor mounts have been replaced twice. Just seems the fluid filled mounts don't hold up as well with the engine weight. Both times I had excessive vibration at 55-60mph and thought it was a tire balance issue - turns out it was the motor shaking the car at a specific RPM that I could feel. Both replacements were in Arizona - seems heat takes a heavy toll. Haven't had to do them since moving back to the East Coast. There may be an aftermarket option to replace them with full rubber mounts, but that may increase vibration.

pjw1967

'14 GL450. Mine were replaced at 46k. Shudder on start up was the symptom.

opto_isolator

Damn... So glad I bought the extended warranty! I hope to keep this thing for awhile

CA_Tallguy

See attached -- I think transmission is the same instructions but engine mount document is for diesel om642. I don't think it is terribly hard on most cars to do these but it can be tricky and hard to get to things. I would plan to have ramps at the very least.

Here is photo DIY for W164 so it could be pretty similar
https://www.youcanic.com/u/mercedesm...w251-w164-x164

You can get quotes on sites like Wrench, YourMechanic, and OpenBay for free.

YourMechanic quote was surprisingly reasonable and they come to YOU. I have used a similar service, Wrench, and a guy came out and swapped my alternator for $150.

OpenBay is different and gives you quotes for local shops but i have not found pricing to be amazing. They seem to quote based on the hours listed for the job in the Mitchell system and those hours are padded. But it can be useful for a general quote. They will also quote you if you labor only if you supply the parts.


https://wrench.com/referral/TWNTGC ($25 discount with this link)
https://www.yourmechanic.com/rl/fa27jg1644199 ($10 discount)
https://www.openbay.com/invite/a2svep