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Now that I finally have DAS, I have answers (and more questions).
If I disable the TCC lockup solenoid via star, I have an entirely different car (in the best possible way). I've been chasing the feeling of being bogged down, in too high of a gear etc, and my thoughts of early and too aggressive lockup are now confirmed. It's felt like a manual transmission car, holding gears on deccel etc.
Now the tricky bit - I've replaced the TCC solenoid already. Prior to the the car developed a hard, and I mean HARD, lockup the minute I started moving and it wouldn't unlock until I came to a stop. It was almost undriveable. Replaced the solenoid and thought all was fixed, but only since it was such a massive improvement.
I've replaced the valve body (good used unit), conductor plate, swapped TCMs, fluid level correct and fresh.
Here's the million dollar question - If disabling the TCC w/ Star fixes my issue, could this be anything other than a bad TCC solenoid?
I'm trying to locate my receipts to find a part number, are there more than one that a parts supplier could have given me? It seems unlikely, but worth ruling out. Could some unseen, internal issue w/ the valve body be causing this? Shifts are good, clutch pack fill times all really good, no symptoms of speed sensor issues w/ the conductor plate (although I believe the PO replaced with an aftermarket one as it didn't have the MB logo stamped on it).
Lastly, could an issue with the torque converter itself cause this? I'm hoping not as I'd rather pull a pan vs the transmission...
Right now all I want to do is hook up DAS every time I drive the car to disable this haha. Thanks in advance for any insight!
Anyone? More info from testing today, I find myself leaning towards a bad torque converter. The chance of a new TCC solenoid being faulty is very low, and if my shift and fill times all look ok it probably isn't a valve body or trans issue either.
Here's the graph that I'm sure some of you are familiar with, I can see w/ driving that my TCC doesn't go to 'OPEN' until I'm almost at a dead stop. Computer shows 'SLIPPING' all the time once the car gets moving. Verified that at 1000 rpm of trans output speed and my foot off the gas completely, TCU still shows 'SLIPPING' when it should be open, and you can feel it unlock as the car is almost at a stop. I'm wondering if something is just buggered in the torque converter and causing all sorts of odd pressure.
I know mine's an '03 and it did have the Valeo radiator, however I changed it out when I got it and had my fluid tested - completely clear of glycol. That's not to say a previous owner could have had that and did a flush at some point.
Maybe time for a high stall? With how well she drove turning off TCC w/ Star, I'd assume it would be another jump like that to go to the UPD unit, traction be damned.
I will ask a stupid question....are you really sure there is something wrong with it? What you describe is how an E55, and many MB's of that generation drive. They were clunky when brand new,and yes the torque converter lockup feels like, and is, engaged at low speeds, even in a parking lot. It's just a quirk of MB's design. Yes, it feels smoother when you shut it off tbrough DAS. But you can't bypass it or your 5th gear overdrive would suck. On the opposite end of the spectrum, the '99 E300 Turbodiesel which uses the same transmission has NO lockup at all, and a lower gear ratio which made highway driving miserable with 300 RPM slippage. Just a little FYI.
P.S. Your "good used" valve body makes me nervous. Are you sure it's the exact same part number and version as your original? There are dozens of part numbers and supercessions.
Last edited by E55Greasemonkey; Jan 29, 2020 at 07:32 PM.
I will ask a stupid question....are you really sure there is something wrong with it? What you describe is how an E55, and many MB's of that generation drive. They were clunky when brand new,and yes the torque converter lockup feels like, and is, engaged at low speeds, even in a parking lot. It's just a quirk of MB's design. On the opposite end of the spectrum, the '99 E300 Turbodiesel which uses the same transmission has NO lockup at all, and a lower gear ratio which made highway driving miserable with 300 RPM slippage. Just a little FYI.
I've asked myself that same question several times, but I also can't fathom how merging at 30mph, in a car like this, feels unsafe because the car is locked in gear at 1100rpm and will barely get up and go. Unless you really stomp on it and then brake the back end loose..
I've looked through so many threads and have on multiple occasions seen the question posed "does turning of TCC in Star make a difference? If so you have your answer"...although for the life of me I can't seem to find a thread that ends in an answer to that! Turning off TCC makes this car feel like it's making 2x the power. At least. It's astonishing.
We have a Jeep SRT8 that also has the 722.6 transmission, obviously some differences in Mercedes control, but driving the two cars it feels like the E55 has some serious issues with the trans.
I don't remember for sure, but see if there's a torque converter (re)adaptation you can perform with DAS. It should be under "adaptations" Some models have it.
I don't remember for sure, but see if there's a torque converter (re)adaptation you can perform with DAS. It should be under "adaptations" Some models have it.
Yes, I've reset adaptations in DAS, and did look over the menu for re-adapting the torque converter (it warns only to do if you've put in new parts etc).
I have two concerns with this, the first being the barrier to actually do it. While I can awkwardly drive around my neighborhood trying to keep steady speeds then stopping every 10* for 20 seconds, it wants to continue at a steady 30-40 until trans temp reaches 80 deg. I'm convinced that is actually impossible. I barely get above 50* after 20 minutes of driving. The other test to adapt at speed requires two people and a ton of open, level space, I just don't think I can do it accurately/fully where I live.
I can't drive out anywhere remotely either as the car has to be dead cold when the test is started. If only I lived at an abandoned airport!
Second concern is that I'd imagine it would adapt on it's own at some point. I could see needing this if I put a new transmission in, but it seems overkill for mostly maintenance parts being taken care of.
Yep! Welcome to the wonderful world of MB engineering. You should see the full page document MB just released about adapting the new AMG models. It's a joke, and would require a private race track with no other traffic.
You can always just reset the TC adaptation and let it learn on it's own. It could get better, or worse though.
We fix many shifting complaints at the dealership using the adaptations, and no parts have been changed. As a matter of fact I recall a service bulletin for bucking transmission complaints when the E55 was new. I'll try and find it tomorrow if MB hasn't deleted (lost) it.
Last edited by E55Greasemonkey; Jan 29, 2020 at 07:55 PM.
Yep! Welcome to the wonderful world of MB engineering. You should see the full page document MB just released about adapting the new AMG models. It's a joke, and would require a private race track with no other traffic.
You can always just reset the TC adaptation and let it learn on it's own. It could get better, or worse though.
Oy I can imagine.
Only reset available to me on DAS is shift adaptation reset, the TC adaptation is only though those tests based on what I could find. And I'd assume the adapting is done in the TCU since that is the control module you access to do that (vs the ECU), so my trying another TCU with no difference may rule that out as my issue, which is why I'm leaning towards a mechanical issue like the TC itself. If anything maybe a high stall will mask my concerns at lower rpms with the added slip!
I can only suggest you find another E55 to drive, or have someone with knowledge of these cars take it for a test drive. Both options are somewhat difficult on a 17 year old platform.
I can only suggest you find another E55 to drive, or have someone with knowledge of these cars take it for a test drive. Both options are somewhat difficult on a 17 year old platform.
Good call. I thought about going to test drive one at a local dealer, but feel a little odd having to lie to them about why I want to drive it, and for all I know it could have issues too (it's an independent lot...). I've posted in the PNW forum, we shall see!
Well no response from any local folks, however I thought I'd snap a quick video on my way home today. The first and last accelerations are w/ 40% throttle that is fairly quickly applied (I know if you're slow it will want to stay in gear to keep things smooth), yet no change and no slip or uptick in rpm at all. This is my main concern, headed down the road at 35mph and I only have passing power if I really mash it.
Also, if you turn up the volume and listen to the downshift when I give it 70% throttle, I hit the gas once I say I do, so you can hear the delay and 'warble' of the engine note as it finally applies power. This seems much more pronounced than just torque management.
You're transmission is in comfort mode in the video. Have you tried sport mode to see if any difference?
No difference, same goes for a DTK tuned TCU I picked up last year to try.
Sport mode will shift at a higher rpm, but once I'm done accelerating and it settles on the highest gear for that speed, it lazily glues itself like this.
By the video it looks normal. I will try and take the car out and drive just like you did and see. I never really paid attention to it driving like you did in the vid.
By the video it looks normal. I will try and take the car out and drive just like you did and see. I never really paid attention to it driving like you did in the vid.
Thanks, I'd be curious to see if you get any rpm raise and slip in those conditions. The thing that irks me is that according to the TCC control graph, the solenoid should be Open when I'm under 1300-1400rpm in trans output speed, and mine isn't. It only goes to Open when I stop. And my initial acceleration from a stop is just fine.
I just drove mine in comfort mode and it acted the same at part throttle. I'm heavily modded so I do have more power on tap, at the slightest touch of the gas pedal.
I'll try sport mode next.
I rarely drive like that, it is an AMG ya know!
That graph you're looking at is a generic representation of all 722.6 transmissions. Read the fine print.
How long have you owned this car? I'm still convinced you are chasing a ghost.
Last edited by E55Greasemonkey; Jan 31, 2020 at 12:04 PM.
I just drove mine in comfort mode and it acted the same at part throttle. I'm heavily modded so I do have more power on tap, at the slightest touch of the gas pedal.
I'll try sport mode next.
I rarely drive like that, it is an AMG ya know!
That graph you're looking at is a generic representation of all 722.6 transmissions. Read the fine print.
How long have you owned this car? I'm still convinced you are chasing a ghost.
Interesting... I've had the car for almost 2 years, when I got it shifting seemed ok but the intercooler pump was totally dead and the PO was a lady who just drove it on the highway, NOT the way an AMG should be driven
Since then I've added extra cooling, 77mm pulley, 550cc injectors, RaceIQ tune, and full top end reseal w/ a 580 blower, so she makes plenty of power!
I may try another video of shifting during a WOT pull, seems much slower than it used to be, like toss your head forward for half a second, then back again when it finally engages. Engine is running beautifully, fuel trims even with a boxed Tony tune are under 3%.
I may just pick up a used OEM torque converter, I have a small rear main leak that should be taken care of anyway, at least eliminate that as a possible issue and it's only a couple hundred bucks out of pocket.
In my maybe-not-so-crazy defense, it was pointed out to me last year when my TCC solenoid failed that I could be imagining things, then I went for a drive with a tech and he was shocked at how badly the TC was locking up, told me that I was right saying the car felt undriveable. This just feels like a '50%' failure of the same thing, but I know that isn't possible.
Really tough to diagnose this over the internet. I just drove in sport mode, anything less than half throttle the rpms don't move but the speed increases/car accelerates. Going past half throttle the rpms jump up and yes, it takes off quite harshly and fast.
I just did my rear main. Keep in mind it's not the seal that leaks, it's the black sealant on the plate. So you'll need the seal, plate, sealant, 4 crush washers for the trans cooler line and .5 to 1 qt of atf fluid (more if you replace the converter)
Last edited by E55Greasemonkey; Jan 31, 2020 at 12:57 PM.
That chart is not valid for your car. It is a chart from 1997. Strategies and tech changed a lot. Your tcc should be in controlled slip pretty much all of the time. Slip is very little typically between 5-100 rpm of slip.That is what it is supposed to do. It is for fuel economy and pretty much every car on the planet runs this way. It is better to downshift than unlock the converter. Mercedes and most German cars have very different shift patterns than U.S. cars. They require a lot of throttle to downshift and will typically upshift quickly as well.
So on a cruise to tip in downshift. You will typically get maybe one gear shift down and then if you hit the WOT switch get passing gear. This is how it is supposed to work.
I suggest you go drive another car to see. Also you have driver adapts. So if you cruise a lot at light throttle it will require more throttle to hold gear and downshfit. But if you drive aggressively it will adapt to you and hold gears longer and downshift sooner. But that is a few minutes either way. So if you get on the highway and drive like grandma for an hour then ask it to downshift it will require a lot more throttle than if you were stop light to stop light beating on it.
Interesting... I've had the car for almost 2 years, when I got it shifting seemed ok but the intercooler pump was totally dead and the PO was a lady who just drove it on the highway, NOT the way an AMG should be driven
Since then I've added extra cooling, 77mm pulley, 550cc injectors, RaceIQ tune, and full top end reseal w/ a 580 blower, so she makes plenty of power!
I may try another video of shifting during a WOT pull, seems much slower than it used to be, like toss your head forward for half a second, then back again when it finally engages. Engine is running beautifully, fuel trims even with a boxed Tony tune are under 3%.
I may just pick up a used OEM torque converter, I have a small rear main leak that should be taken care of anyway, at least eliminate that as a possible issue and it's only a couple hundred bucks out of pocket.
Don't buy a used OEM TC.
Get one that's rebuilt at minimum.
It's a wear item as you know.
I'm thinking I have a bad TC too, I need to upload the video of my symptoms.
But basically from a stop I can give the car 15% pedal and the car drives fine, but if i were to give it another 10% the car feels like it's downshifting very hard.
It does this in 1st through 3rd, anytime i am gradually accelerating then i give it more it will do that shudder.
I also have some driveline vibration even after replacing motor/tranny mounts and the flex discs
The vibration is very apparent around 50mph~ around 1500rpm
Don't buy a used OEM TC.
Get one that's rebuilt at minimum.
It's a wear item as you know.
I'm thinking I have a bad TC too, I need to upload the video of my symptoms.
But basically from a stop I can give the car 15% pedal and the car drives fine, but if i were to give it another 10% the car feels like it's downshifting very hard.
It does this in 1st through 3rd, anytime i am gradually accelerating then i give it more it will do that shudder.
I also have some driveline vibration even after replacing motor/tranny mounts and the flex discs
The vibration is very apparent around 50mph~ around 1500rpm
That's a good point. However if it turns out this is 'normal', maybe I should opt for a UPD 3k stall, maybe I'll enjoy driving the car around town more. It's spendy but I've mostly head great things.
I too have some vibration (and new-ish mounts) but when I had my exhaust work done the shop had to modify some mounts and I'm pretty sure there is a lot less rubber and movement, so I've attributed my vibrations to that, especially under load.
OK, now that several voices have chimed in about this being normal, it's led me back to the engine. I've got a decent bit of mechanical background, and after all my fussing around I was mostly concerned w/ fuel trims, MAP and throttle readings etc (which are all great).
One thing I never really looked at was timing. Most threads I've looked at are people complaining of issues w/ heat soak and IATs, but here's a video of my 'problem area', fully loaded in 4th gear at 40mph. Does that timing jump seem right, should it be going to 0? I'm thinking not, and now scratching my head if it's an engine issue after all...
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