I'm helping a friend to revive his 2006 CLS55 AMG that has been in storage for 10+ years. It hasn't been started or moved. (posting in E55 instead since there's a lot more people here)
The car has only 14k miles. It ran perfectly fine before it was put in storage.
The car started right away with a jumper, and it was briefly driven out of the garage, and was towed to a general repair shop nearby for inspection, fluid changes, and other maintenance items.

The shop did a number of things, the usual fluid changes, tires, filters...etc.

Upon picking up the car and started driving, I immediately felt it wasn't right. It took a lot of effort(gas pedal) to start moving, and it felt like the torque converter was not locking up properly.

On the highway, it would not shift past 3rd gear. it seems it was always in 2nd and 3rd.

Occasionally it would "pop" out of a gear, as if it was in Neutral. the engine would free rev. Happened a few times at a stop.

After I restart the car, it seems to behave normally, it would start in 1st gear and shift through all the gears even 4th and 5th, however shifting is very rough.
and as soon as I press the throttle a bit harder, when in 3rd or 4th gear, it would "pop" out of gear and car is in neural again. a few seconds later it's stuck in 3rd gear, and the same odd behavior returns. the whole time this is with shifter in D position.

once it does the "pop", MIL is on.

with a cheap scan tool, all I could see was "incorrect gear ratio"

I took it back to the shop, they used a shop scan tool and it indicated "1st, 2nd and 3rd gear slips", "TCM or TCU communication failure".

The shop suggested to replace the conductor plate and all the other related seals , gaskets..etc and see if it will improve.

I asked the shop a few times, when they flushed the gearbox oil, did they refill properly, they said yes. when I asked them if they have the MB gearbox dip stick they didn't have one. how do they make sure it's a proper fill without the dip stick??

Do you guys think an improper fill can cause all those issues above?

Or can it go bad simply because it sat for 10+ years ?

Much appreciated.

 

Conductor plate. Electrical bushing. Transmission fluid fill level.
It is one of these. I would place my bets on the first, then the second, then the third.
Electrical failure results in the car remaining in one gear until the TCU module is reset using STAR. Hydraulic/mechanical issues will reset with key on/off.
If the conductor plate is replaced after a malfunction, you *must* clear the codes using STAR/DAS/Xentry before the transmission will operate properly again. This was designed into the system to prevent additional damage to the transmission.

 

I would check for tcu oil contamination as well. Jumping these cars is a risky proposition that many times leads to problems, and weak batteries can also lead to these problems.

 

And when jumping these cars, do NOT have the key fob in the ignition when the jumper cables are attached! If car equipped with Keyless-Go, keep the key fob at least two meters from the car when attaching the jumper cables.

 

Car is now running perfectly!
The shop replaced the conductor plate, seals, o-rings...etc. Reset the TCM. No more issues.
No oil leaks of any kind whatsoever, maybe some part of the electronics in the conductor plate went bad.
I guess some cars can have issues from sitting around for too long...

 

That's a long time to just sit. I bet a lot more problems come up for him for instance - all kinds of rot in all the suspension components, let alone the engine.

Why did it sit so long?

 

i'm surprised the air bags are still in good shape after it sat on the "sagged" position for so long.
I've been driving it so it can be ready for smog, the car runs like new. no noise or any issue.

He bought the car in 2005 and he decided to move back to China in 2006, but would visit the US every once in a while.
He hasn't come back since 2013...

 

I would be concerned with the fact that the shop doesn’t know how to fill the fluid.

As far as I’m aware, all supercharged 55 engine have a transmission fill tube in the back of the engine. You remove the lock off of that tube and use a shop dipstick tool available from Mercedes or in the aftermarket. If they just filled the tube with the “correct “amount of fluid but didn’t check it with the dipstick, it’s unlikely the level is correct.

 

Baltistyle is correct but it goes much further then that.
I will tell you more than likely what happened to your friends car. The shop that did the work,refilled the transmission in the wrong dipstick tube and never new. The transmission fluid was put into the engine and then transmission becomes very low on fluid. The fill tube has a red cap on it and at first look that is where the fluid would go. It is not. The tube even leans downward towards the transmission but that is the engine fill / removal. The transmission fill is a tube that is VERY well hidden if you are not looking very well All your issues point to this and I'm sure that this was figured out at some point when returned to the shop and they corrected it. Not only have I "seen" this, I myself have done it and learned the hard way on my first week of car ownership and had the exact same issues. LOL
Make sure the engine oil is where it should be as well.

 

crap, I had not read there was a fix mentioned. glad it was sorted.

 

I did notice a slight knocking noise at low RPM when the car is warm, sounds like a noisy lifter.
I hope it's not what SICAMG said , that the shop put ATF in the engine oil...

 

Me too but sure sounds like it since few shops know anything about these cars and it is a very easy mistake to make.
Everyone forgets that even though they hold there modern style look over the years....it's a very old platform. How many do shops including dealers do they actually see ?
Hell I can't believe my E55 is 20 years old now ! But your good now so that's all that matters in the end.