Hey everyone, I bought a 2014 Mercedes E350 in Spring 2023 with 43k miles on it. Since then, I have put 12k miles on it. I recently noticed that the downshift from 5th to 4th gear while accelerating quickly at 60 mph today. I dug into the previous owner's service records, and realized that they did not get the 40k mile transmission service done. Could this have had irreversible impacts on the transmission for my car? I have read many threads on this website, each of which has a different solution ranging from software updates, so I am pretty confused. I thought the w212 platform was bulletproof, but am now questioning my purchase.

 

It's bulletproof because it is high maintenance.
Tranny ATF is ultra low viscosity... as soon as its seasoned its harder to adapt clutch pressures to it!

The only thing irreversible are mechanical damage and clutch sludge jamming your solenoid screens... get your 722.9 serviced with blue ATF (NOT RED ATF)

Then get on schedule with

• ignition tune up
• CPS leakers + pig tails
• rear diff oil
• engine/tranny rubber mounts
• brakes pads + rotors
• suspension control arms

then enjoy until 100kMi!


+++ I almost forgot... "miscellaneous low voltage issues".
Buy yourself a CTEK float charger for help against low battery voltage.

 

Would you mind posting the source of your 40K miles transmission service interval? Your are referring to a MY14 E350 sedan, correct?

Per MB MY14 for E class, tranny is serviced at 70K miles. Here is my source MY14 maintenance manual

 

Well any mechanical device with its life and death based on fluid..........is only good and bulletproof if it is serviced/maintained well.
If since 2014 to today ur tranny is still using its original old oil, that is 10 years and way pass the limitation set by MB at 7* years ( *too long ). In my country they set it at 5 years 70,000KM.
If you plan to keep your car to 2034, per 3 years or 35,000 miles is as far as I would push the tranny oil.

 

Yes exactly, maintenance is important, you treat the car well, usually it will service you well as long as it doesn't have defects from factory or design flaws.

 

Other than factory scheduled maintenance, recommend looking into preventative maintenance as well.

 

Preventative maintenance is important, but also consider the possibility of MIFs (maintenance-induced failures)...

 

No need to worry, Mercedes-Benz trannies kinda not as smooth as Japanese EAT8 trannies . Yes, W212s are hardshell to me

 

> Do you want to make your 722.9 shift seamlessly better than new ?

The issue IS NOT TRANNY but poor engine fuel map causing laggy throttle.
The tranny can not adapt well to poor factory condition.

Cancel the engine throttle lag then tranny will match engine seamlessly beyond expectations.

Don't ignore clutches banging gears at the wrong time. The least you can do is take it easy while good adaptations are impossible.

 

It might be caused by having ALT-LIN as well, just saying : )

 

Ja, dat's 100% correct!

The one thing I can not speak of are the results of ALT-LIN without MOD-4.

What's for sure is laggy engine, bangging tranny and extreme heat soaks come from the factory setup.

This is fixed experimentally with stable oil pressure + stable voltages. No parts needed.
​​​​​​

 

Couple of options are available. But first, because of the age, I would get the tranny properly serviced (drain and fill) as @S-Prihadi stated. Other steps to take are a transmission reset using XENTRY and an alternator LIN disconnect. The YouTube hold the pedal down while turning the car on and off may help, but a proper reset and calibration is better. The other discovery I most recently made is to disconnect the LIN line to the alternator. I still need to do some more observing, but it seems to smooth the transmissions in both my cars. Learn more here.

 

MOD-4 is valuable as well not going to lie.

 

I would leave alone the tranny adaptations. It's temporary effective until tranny relearns poor shifts again.

Fix weak throttle lag then tranny will adapt well.

 

I've seen 150k transmission fluid on a W220 S500 that threw a code from low fluid that was fixed with a simple service including 2L of rinse thrown in. 40k isn't gonna hurt anything it's just old and thickened so the solenoids are strugglin.

 

I would consider the following “:

- replace the fluid with oem or preferrably better alternative that doesn’t prioritize fuel economy at the expense of good quality additives.

- look at your intake/pcv/fuel system. Consider fixing pcv system with new valve, hoses, gaskets. Look at whether your hpfp has degraded over time causing sluggishness or incorrect fuel map. Check if your intake system is properly sealed.

- AVOID modifying electric system as suggested by some members. Slippery road leading to more potential problems. Definitely not needed if your systems work fine, you will have smooth shifts and amazing accelerations/decelerations. No need to invent a bicycle on a Mercedes engine.

- Consider resetting and performing transmission adaptation. This step is very important and often done incorrectly without any good results. Trust the process and the tools, and again, beware of unnecessary unapproved mods that serve as a bandaid to misjudgment or bad original diagnostic.

 

I detect some healthy and prudent skepticism. However, there is a growing base of members here that have made these "modifications" with positive results and no negative consequences for thousands of miles over a year of driving. Before poo-pooing these recommendations, do the research and even try them, but at your own risk. While intuitively you may think to leave things alone, you shouldn't dismiss anything until you have proof they don't work.

 

Ya, they are experimental. A lot of systems MB designed was to help with fuel economy and emissions, not mainly with the health and longevity of the engine in mind. That said, perfectly fine to leave it stock if you are worried.

 

Let me add, they are experimental yet data proven, with lots of testing and analysis of such by forum members performing on their own cars of which their names are mentioned in the oil pump solenoid thread and to share them for the benefit of us forum members.

 

40 years mechanical engineering here. Had the honor of working/interacting with international recognized engineers. Respect for my fellow colleagues from anywhere, and still have not met the one that "walks on water".

MB engineering may have some of the best in the world, but it is flawed by design: they are humans. So no need to idolize anyone.

The work by Master Surya and Cali will pass acid tests in any company as long as bean counters are kept in a cage

 

I don't even think the engineers made mistakes, per se. They have to work in a more complicated environment every year, with additional requirements piling up due to regulatory needs and consumer demands. Their hands are often tied by the compliance officers, legal requirements, finance/sales, and even the marketing department. They're still doing an amazing job given those constraints.

 

​​​​Daimler-Mercedes is clearly the worldclass leader.


Don't unplug anything without a personal understanding.

Experimental mods are best left for literate individuals with a goal.

 

Agree, both of the aforementioned names are two of most valuable forum members and contributors here with lots of knowledge on these cars especially the M276. They know more than a lot of people and even most forum members here knows more than the salesperson here.

 

Do agree as well in terms of the main issue being bean counters and regulations and other pressures.