Hello! I recently purchased a W219 (2008 97k mi) from a guy who had just replaced the radiator. Pulling out of my house the other day I noticed there was no power going to the wheels. Luckily I was right outside of my driveway when I stopped because I opened the door and saw a tsunami of ATF flowing out from under the car.

As you may have guessed, the guy who replaced the radiator did not connect a transmission cooler hose correctly. I got the car towed to an independent MB shop where they fixed the hose, put in 8 quarts of Liqui Moly ATF, and the reported the car driving and shifting well. The car now shifts and drives perfectly under normal conditions BUT if I step on it hard the RPMs will shoot up and power to the wheels will cut out similar to how it felt when my fluid had leaked out. This condition happened once in 1st gear and once in 6th gear (both in manual mode). I am obviously not going to do this again now that I have noticed it, but when I was in 6th gear and gunned it the car redlined and then I realized, ****, I am only going 100 mph this isn't right... I need to drop a gear or two in if am gonna gun it like that. I then tried this again in first gear and it did the same thing, which seemed like less of a problem of gear selection to me and I started thinking something might be wrong.

My question is am I an idiot or is this normal? Again I have no codes, no noises, shifts and drives perfectly. Is it normal for the torque converter to slip under the massive torque of the M273? I am new to the V8 world but not to 7g and I never noticed this behavior in my 2008 CLK 350. I really appreciate y'all's advice and, hopefully, peace of mind. Really wishing that idiot frat kid had not totaled my perfect W209 right about now.

 

you have no fault code when your tranny is acting up.
That's a bit unsettling.
Before pouring money into tranny repairs be absolutely sure your compatible ATF is not messing up your tranny adaptations.

 

Roger that, I will do the reset procedure. Also, I should have said no check engine light... I need to have the shop fully scan it for codes I suppose.

 

It's a Mercedes... more than just the TCU are able mess up shifts: CAN-Bus C (ESP; ISM; ECU;...) can rope in chaos.
Shifts actually rest on ECU stability. When engine does not run right shifts adaptations become poor.

Beside WOT everything else ok?

 

Interesting! Everything else is seemingly good, I did have a check engine light for MAF so I installed a Bosch replacement sensor along with air filters which smoothed the engine out considerably. The car has a SUPERB service history at the dealer (one owner car) so I’ve just been slowly getting a baseline on service… oil change, idler pulleys and belt, etc. I do loose sleep some over the Air-Matic system as only the front struts have been replaced.

 

What's in the cards is a $8k tranny rebuild job you don't want to be walked into.

It's easy to get helped and even easier not to get helped at all... is a way of saying make sure you're paying to genuinely get helped OUT.

 

ANYBODY owning a Mercedes MUST have a good Mercedes-specific scan tool!!!

DO NOT rely on some light on the dash to tell you if something is wrong. My dad, RIP, used to call dash lights idiot lights and you can guess why. Clearly, the tranny should not be slipping on a stock car.

That said, check your invoice from the independent shop and see what exactly they put in your tranny. A 2008 probably uses ATF-134 (MB 236.14). But check for sure for your car by entering your VIN on www.lastvin.com and look for code A89. If not there, then you use the red ATF-134 fluid. If you have code A89, make sure they used blue ATF-134FE (MB 236.15) fluid. They are NOT compatible.

 

Do you have a recommendation for a scan tool?

 

Ideally, you want XENTRY. But, an excellent and inexpensive tool is the LAUNCH Creader Elite 2.0 BENZ. You can get it on Amazon or KingBolenTool for less.


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