broncc

A bit of a background first. I have a 2007 E280 CDI 4MATIC (hence the 722.6 and not 722.9) with 200k km (124k miles) on the odometer. Soon after I bought it from its second owner, I noticed that the first few shifts when the car had sat in the cold were very rough. After some reading I reached the conclusion that it was the torque converter clutch solenoid which seems to be a common failure on these. I replaced it in January together with the filter, gasket, harness connector and 4L of oil (Fuchs Titan ATF 4134) and the problem disappeared.

The past few months I have experienced the following problem - when the car shifts from 1st to 2nd (or 2nd to 3rd if in 'C' mode), just before the actual shift, I can see the RPM drop from ~1800 to ~1600, there is a slight jolt/jerk and then the RPM get back to 1800-2000 and the car shifts to the next gear. This happens most often when I apply light and constant throttle, e.g. when I set off from a light and there is traffic. It feels like the torque converter slipping/engaging but not in the way it was designed to thus causing the jolt/jerk. This doesn't happen if I push the gas pedal hard. I've also experienced a few more violent jolts/jerks but maybe two or three times during my two years of ownership. I tried adding two bottles of Dr. Tranny Instant Shudder Fixx but there is no change. I also tried resetting the adaptations via Star to no avail. The fluid level is at the top range of the 80*C level when the car is at operating temperature.

The previous owner had replaced the transmission oil a few months before I purchased the car at around 180k km (112k miles). I asked the local MB dealership for all the invoices they have on my car for servicing (which was done there up until 100k km (62k miles)) and there is none on transmission fluid changes.

I am not completely sure I started experiencing this issue after the TCC solenoid replacement but even if it happened in the past, it was less noticeable. Do you think the previous owner might have noticed this and added some additive when he replaced the transmission oil to mask it so when I drained the oil and put new one in, the problem become apparent again?

At any rate, I need to figure out what to do now. I disabled the TCC solenoid using Star and the problem wasn't there so it is definitely the torque converter that is causing it. Could it be that the new solenoid I put in is faulty? I don't feel like spending 600-700 euro for a reconditioned TC if it's just a 50 euro solenoid that's defective. I find it hard to believe that the TC has gone at only 200k km.

The worst part is that had I decided to sell the car when the weather gets better but now it has this problem and I am not the type of person to try and sell a car with a major fault..

Any tips and ideas would be welcome.

kajtek1

I hope by "harness connector" you mean famous pilot busing?
Did you check TCU for contamination? Seem 99% of problems on 5G are wire contamination from leaky pilot bushing oring.
There is whole wealth of info about those transmissions on benzworld. Look for topics by MAVA

broncc

I made two videos

- here you can see the rpm drop slightly from ~1500rpm and the car jolts slightly, in a few seconds the car upshifted

- the same happens here but around ~1600rpm, again the car jolted and a bit after the clutch was applied the gearbox upshifted..

broncc

A local mechanic suggested that it might be the valve body and not the TC that's causing this. Any thoughts?

bernie pogoson

When driving on the highway the car does not automatically shift into gear, it freezes. I have to pull over at the side of the road and turn off the car and restart it. I took it to a Mercedes dealership and they said they could not find anything wrong. This has occurred at least 6 times in the last year.

is this related to the problem being discussed coz mine seems different. Does anyone have this kind of issue? How was it resolved please?

laiayo

Hi, did you fixed this issue?
My E200K has the same symptom, I search a lot of threads said that was a bad solenoid cause this jerk.

bernie pogoson

Yes I did. I replaced a switch in the gear system. Bought it from Aliexpress and it was pretty easy to replace. Search for this on Aliexpress: Transmission Conductor Plate+Connector+Filter+Gasket KIT For Mercedes Benz 722.6 140270116.
was like Magic. I think bad transmission oil was what caused the earlier one to fail. If after changing this it continues, then a solenoid may have been affected.

laiayo

I did the ATF, Connector, Filter, Gasket change but the jerk still there.
Like broncc post in #3, mine does the same RPM drop.

bernie pogoson

Only when the switch is not bad, would a change in oil and gasket and filter help. If the switch is bad, you may need to change it. The switch is about a 10inch square, the item on the right. It's located inside d gearbox after u have removed the gear oil pan

laiayo

Thank you!
In my understanding, if the conductor plate is bad I will got the Check Engine Light or some fault code? Right?
But I got no CEL and no fault code, I assume it might be bad TCC solenoid cause it.

I have a jerk when I press gas from stop, the RPM raise to 1800 and suddenly drop to 1600(or1700) and raise again to 2200 to up-shift.
The drop RPM also happen in 2nd gear when the RPM raise to 2400 (suddenly drop to 2300 and raise again to up-shift to 3rd gear).
The symptom is like the OP broncc posted in #3.