2007 E320 Bluetec- weird problem. Trans or engine, not sure - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 12-02-2017, 12:41 PM

I got my most recent car on the road yesterday, and it is exhibiting some weird issues with the engine, or transmission, I am not sure which. When starting off, it will loose complete power for a split second, and then come back on (akin to turning off the ignition for a fraction of a second, and back on). I think it is right at the moment it is shifting into second gear, but am not exactly sure. I scanned for DTC's, and found only transmission related codes. 0894 The gear is implausible or the transmission is slipping, and 2232-001 Transmission control ETC fault 15.
I would have thought I would find an engine related code since the power goes away for a split second, but there are none.
For the trans, I replaced the filter and gasket, as well as drained the pan and torque converter. I put in synthetic ATF. I assumed the fluid had not been changed in the 73,000 miles since the car was new. I did this after looping the trans cooler lines after the collision so I could move the car. I had to use a garden pump sprayer to force the ATF into the trans through the cooler line, it worked great.

Even though it has this problem, the car is still drivable. I hope there is no damage being done......Rich

Murkybenz · #2 12-02-2017, 01:21 PM

My 97 w210 e300 turbodiesel did this random power loss hiccup off and on for around six months , if you get the revs/speed at the right place you can sometimes get it to do it but its the slightest hiccup thats almost unoticable but you have that “did something weird happen then” feeling.
I fitted new maf sensor but it still misbehaved and eventually started going limp mode stuck in 3-4-5th gear that only a restart would cure. I replaced gearbox speed sensor plate after it shut down into full limp with only reverse and 2nd gear and had codes cleared (only a months old maf code existed). There was a shift spring I replaced as well as it was in about five pieces (1-2 or 2-3 shift ?).
Anyway that cured it and its been fine ever since, but yes that odd hiccup was where mine started going wrong.

GregMN · #3 12-02-2017, 03:37 PM

Monitor the fuel rail pressure in real time.
I use an UntraGauge

It's a start.

ROLLGUY · #4 12-02-2017, 05:54 PM

Quote:

Originally Posted by GregMN

Monitor the fuel rail pressure in real time.
I use an UntraGauge

It's a start.

I am able to do that with my MB II, but would there not be an engine DTC for any fuel related issue? The "hiccup" happens so fast, I doubt I would see anything out of the ordinary while monitoring the fuel rail pressure without a DTC.
Having only transmission codes, I wonder if the trans is not communicating correctly with the ECM. I also wonder if I did anything to the trans while servicing it. The trans worked flawlessly before the accident.

GregMN · #5 12-02-2017, 08:01 PM

Well, fine. Make a list of each item that could cause a momentary hic-up in the engine running and monitor it during the event. Maybe have someone else drive. Work the list until you find it. I have engine hic-ups that, frustratingly, do not throw a code on my 642.

ROLLGUY · #6 12-02-2017, 08:06 PM

Update: I found out that it only happens from first to second. Once it is past second gear, I can mash the pedal and it will accelerate like normal. I may try to look at the live data for the trans. Again, it happens so quick that I may not see anything on the display that is abnormal. Also, if I take off real slow, it shifts/accelerates normally.

Murkybenz · #7 12-03-2017, 05:35 AM

Mostly these gearboxes do have a tendency to do what yours is doing but only the once on first drive on a cold engine, it seems these boxes suffer numerous glitches.
This link below has a lot of information
https://mbworld.org/forums/attachments/gl63-amg/414797d1510673287-friction-power-torque-converter-lockup-clutch-too-high-722.9_tips-1-.pdf

ROLLGUY · #8 12-03-2017, 11:08 AM

Quote:

Originally Posted by Murkybenz

Mostly these gearboxes do have a tendency to do what yours is doing but only the once on first drive on a cold engine, it seems these boxes suffer numerous glitches.
This link below has a lot of information
https://mbworld.org/forums/attachments/gl63-amg/414797d1510673287-friction-power-torque-converter-lockup-clutch-too-high-722.9_tips-1-.pdf

Thank you for the great source of info. Just looking at the photo of the transmission cut-out illustration causes me to admire the engineers that designed it. It is a pretty incredible piece of machinery.
As far as I can tell, the problem still exists when the engine/trans is up to operating temperature. I may take it for a longer drive today to be sure. Thanks again, Rich

ROLLGUY · #9 12-03-2017, 11:32 AM

Is there a specific ATF for the 722.9? I used Valvoline Max Life synthetic ATF. I am wondering if maybe this might be the problem?
EDIT: I am planning to call Marc at Sun Valley Mercedes Transmissions tomorrow. If anyone knows, it will be him.

Murkybenz · #10 12-03-2017, 11:48 AM

Oil types mentioned in this link
https://mbworld.org/forums/c-class-w203/365242-diy-722-9-7g-tronic-7-speed-automatic-transmission-service-thread.html

ROLLGUY · #11 12-03-2017, 12:09 PM

Quote:

Originally Posted by Murkybenz

Oil types mentioned in this link
https://mbworld.org/forums/c-class-w203/365242-diy-722-9-7g-tronic-7-speed-automatic-transmission-service-thread.html

Just seconds ago I downloaded the PDF's and noticed I had a reply! great minds think alike

ROLLGUY · #12 12-04-2017, 11:23 AM

Quote:

Originally Posted by ROLLGUY

Is there a specific ATF for the 722.9? I used Valvoline Max Life synthetic ATF. I am wondering if maybe this might be the problem?
EDIT: I am planning to call Marc at Sun Valley Mercedes Transmissions tomorrow. If anyone knows, it will be him.

I just talked to Marc, and he assured me that Maxlife ATF is just fine for my 722.9. He said the most important thing is the change intervals. He also instructed me on the proper way to fill the trans. I may be a quart low, and that could be the reason for the shifting issue. I plan to check it out today......Rich

Zulfiqar · #13 12-04-2017, 12:11 PM

a buddy of mine has a similar car with similar issue and sure as rain it was low about a quart on ATF.

jack the car up and use a spirit level to make sure the car is perfectly straight then test ATF level.

btw - ATF 134 is cheap, why use maxlife when you can buy the shell one. Its a bit more than maxlife.