MDHarrill

Hi all, I'm new to MBWorld and hoping to find some help and info to solve an issue with my 2011 E550. I have noticed when the air temp is 55 or higher and during normal acceleration between 1100 and 1500 RPM the car seems to shudder no matter what gear the trans is in. It does not happen on cooler days nor when I accelerate heavy. From what I am reading in some threads, it seems to be an issue with MAF, throttle position, not getting enough clean air, but not a transmission issue. I've started with replacing air filters, but no help. My next step would be to replace/clean MAF. But I have also seen where some people have installed a Sprint Booster. I would love to get some feedback, so that I can head in the right direction. Many thanks!!

Mike

Mud

Don't throw parts at it.
Do you have or will you get a scantool? Even the generic versions will give you real time run data - that will tell you a lot about what O2 and fuel trims are doing, along with MAP sensor and other readings. They can also help figure out if it's an injector issue. Might be a weak coil as it heats up but you'd need to verify primary/secondary ignition pulse, can't do that with an obd2 reader. I use a GTC505 for that, although an inexpensive spark tool might at least give you an idea.
Transmission - change fluid AND filter. It's a bit tedious, I get a shop to do it, but there's DIY on this forum. Old fluid with depleted additive pack is often a culprit of shudder.
In general, if its a new car to you, start with maintenance baselines so you know where you're at.
If you aren't comfortable with doing the DIY scan, take it and get it scanned somewhere where they have MB software. The cost to identify an issue will be worth it rather than loading up the parts cannon.

MDHarrill

I do have a basic scan tool. And it is time for fluid change and filter, although the problem persisted after the last change. I've had the car 2 years and the problem was there from the get go. I didn't notice it as much, but as I got used to the car and more sensitive to it's quirks, the more it's noticeable. I recently had it at the MB dealer to have it scanned for Airmatic issues, but I suppose any other codes would not have been identified, since they weren't looking for anything else at the time.

I appreciate your feedback, and think I'll start with a pro scan!!

Mud

Hmm seems they should have scanned all modules but you never know!
Good luck, please post any results, this sort of symptoms drive a lot of folks nuts trying to solve.

Ungarisch

Does it feel like your driving over freeway shoulder bumps/grooves? Like the whole interior of the car resonates? If so, it's probably the same issue as mine, where the transmission solenoid was clogged and was not fully engaging the clutchpack at low RPMs and I would get "clutch chatter".

I took the complete valvebody assembly out, cleaned all solenoids with a magnet per the instruction video and after I put it back together with a complete fluid flush the transmission was 100% back to normal. I was shiattin' bricks thinking i needed a transmission rebuild, but it was just clutch debris stick inside the B2 solenoid.

MDHarrill

From the research I've done, that does seem to be the fix. I will be going soon for trans service and will have them clean that out. Thanks for your reply!!

Ungarisch

take it to a shop that has serviced the MB 722.9 transmission before, more specifically the valve body. While removing the valve body is very very easy, the transmission wiring plug on the conductor plate is REALLY stuck inside transmission housing, and if the shop is unfamiliar with the method of removal (ie gently prying from the top) they will break the connector off resulting in the need for a new complete conductor plate assembly, which in itself isn't too expensive at around $300, but it will require online programming through MB's online servers, which again most shops cannot perform.

EDIT: also make sure they don't reuse the valve body bolts as they are stretch bolts and cannot be used again after initially torque since they will either snap or worse strip the thread in the trans housing if you try to torque down to MB specs. Again, a competent MB specialist should know this, which is why it's important you take it to someone who knows what they are going.

MDHarrill

Thanks for the info. Meant to note earlier that when the shudder happens, there's no noise, rather it's the feeling of the car slightly lunging 3-4 times per second. But what is baffling is when the air temp is below 55f, it's as smooth as silk, as it should be. Would the solenoid act up only at certain temps?

Ungarisch

yes, mine did the exact same thing is 4th gear, especially when turning and accelerating out of an intersection when the car's at low rpm it would buck and lurch as if someone just learned to drive an manual transmission and let the clutch out too fast. B2 solenoid control 4th and 7th gear. in 4th the car would lurch, in 7th the car would vibrater/resonate like driving over bumps. It may not be the same solenoid that's clogged for you, but it does sound similar.

The reason it;s temperature dependant is because automatic transmission fluid, which is basically just fancy motor oil, is thicker at start/cold temps but since your fluid is burnt due to old age it hold very little viscosity as it heats up.

E550W212

I have been experiencing rpm surging ever so slightly at idle in P and at times I feel like I can feel very slight vibration in a 2011 E550 M273 . Sometimes I can see surging while driving in D as well, but it's usually not high range, the needle moves barely, but it's not on keeping 100% straight like in all other non mb cars I had before. I've been told by MB dealer that it's within tolerance. There were TCM errors, but after transmission testing the dealership said that MB test procedure advised to ignore the codes. Once when revving it a little on a warm engine in P It felt like the throttle body got stuck or something and it'd hold over 1k rpms and surge. Are these early signs of a torque converter failure? Or is it a normal thing for the rpm needle to be moving like that ever so slightly? ​​​​​​I replaced spark plugs thinking it was that since it's at 55k and spark plug service us dye at 60k miles anyways, done transmission service with fluid change, and shifts are silky smooth. But rpm situation is still a thing.

Here's videos of what it looks like

This is that one time when it seemed like the throttle body got stuck, after restarting the car all was back to normal

CaliBenzDriver

The video makes this look more like your tach itself has Parkinson... than actual engine RPM hunting up/down.

Why/how it does that is a good question! Seek answers by:

1- Scan the OBD port for a fresh list of issues

2- Access to on-board live data.

3- Look at your "misfire count" data...


Engine/tranny mounts are known items to stay on top of for vibrations... not RPM surging.




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E550W212

Hello, thank you for the advice. I am getting a scanner soon and will report what comes up on there. Engine/transmission mounts have been replaced. I will be also checking if the throttle body needs cleaning as I have read that could be a reason for rpm anomaly/shuddering at idle.

Another thing is I had the spark plugs replaced and here are my old ones. Most look fine, but 2 are sticking out. They seem to be fully covered, but I'm not sure if that's oil? Because that could be another cause for surging rpms I'd imagine? If anyone has an idea I'd appreciate any input.










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