Mercedes-Benz Forum banner

How do you know you motor mounts are broken?

1K views 9 replies 7 participants last post by  cascade 
#1 ·
Well I have fixed the 500 SEC and she drives great!! When I punch it, it feels like the throttle gets pulled a little and the car gets away on me and I have to be careful. Now it's not super bad it's just very touchy.
I had a old 64 Pontiac that when punched would do the same thing because the mounts were broken and stretch the linkage.

Now maybe I am making a stretch ? It just seems this Euro SEC really zips compared to my other w126s, first gear is too dangerous to use in traffic!!
 
#2 ·
Observe the engine when you give it full throttle, does it jump?

Or, do the same with a helper, put the car in gear, with the e-brake on and your foot FIRMLY on the brake pedal, hit the accelerator briefly, does the engine jump?

If the answer is yes to either of the above, you need new motor mounts.
 
#3 ·
I will give it that test. I can leave the hood open a few feet and tie it off maybe and watch the motor?
On the W126 is there a safety issue with broken mounts ? How do you change them any tricks or any superior aftEr market parts?
 
#4 ·
Undo the motor shocks and slowly jack up the engine and put a flashlight on the mounts....see if they lift out of themselves or seperate, if checking the roll of the engine doesn't work try this route...don't buy aftermarket 10$ motor mounts!
 
#5 ·
Ok so all you have to do is disconnect the driveshaft,gearbox mounts throttle linkage and exhaust manifolds
Then you simply hang the car upside down from the ceiling
If the mounts are good the engine will stay in place however if the mounts are bad the the engine and gear box will fall from the car
(Pro tip ;If you leave the power steering lines and air lines attached it will stop it all hitting the floor)
Then you have easy access to refit new mounts and you flip back over ,like an omlette,to get it all back in place
..Easy...
 
#6 ·
LMAO I think I will try the first trick, remember you guys in NZ are upside down we can do it the other way here.

Oh where should I jack up the motor? PS the car is lowered it's going to be pain.
 
#8 ·
Look at gap between bottom of radiator fan and fan shroud. If hitting shroud or scraping then you know they have collapsed. Eventually it will break shroud as they continue to collapse.
 
#10 ·
I have NEVER had the motor mounts on my50SEC last more than 50,000 miles.

I just consider them consumable ite4ms and replace them now., as necessary..

With a good independent mechanic to replace them, this expense is not tragic.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top