youchillinornah

First sorry for the dumb name made it when I was younger. I have 2010 E350 4matic with 116k miles and I have a vibration at idle that I cannot fix. I changed all 3 mounts didnt really help. I got it checked for vacuum leak and apparently there is none. I just changed the spark plugs with bosch double platinum, mann air filter, and fresh mobil 1 oil change. The engine is clearly vibrating and it gets worse when its cold and worse when in gear. It only vibrates at idle ~550-600 rpm so at start up when idle is high no vibration but once it goes down it starts vibrating and when I put it in gear and it drops even more the vibrations get worse. If I give it some gas and raise it to like 700 smooth as butter. While driving around its smooth. I feel a little of hesitation when accelerating at ~3-4k rpm but only at partial throttle and for a little bit. I checked MAF by unplugging it and starting it up and it still was vibrating. NO CEL and NO codes. When the engine gets warm it gets alot better sometimes goes away depending on how long its been running and how warm it is out. I tried one bottle of techron and only use 93. I also get a vibration coming from the engine/under the dash area Im assuming from like where the trans connects when I turn the wheel when my car is at idle and its cold. Gets better/ goes away when engine is warm. This doesnt happen at low speeds just when stopped I dont have any issues with turning while moving or anything like that its just at idle when cold. Thanks for any help.

Rafichicago

Vibrations you feel believe it or not could come from suspension. Car has an air suspension. Sometimes you get used to the ride and think that everything seems fine. It might not. I’ve had a suspension problem. Cars strut would over pressurize and would cause a harsh ride. You’d feel engine vibration because of that. You might check that out.

Windwagen

Wow - no answers? My 2011 e350 wagon is 100% the same as the OP describes. I haven't changed the motor mounts. I don't see the motor moving at all either.

Youchillnornah...did you you ever get this resolved? Thanks

Arrie

I thought the idle speed should be like 700 rpm. You might have idle speed too low?

Windwagen

If I add a little throttle, it definitely smooths out...700 rpm seems right. So....how do I set the idle speed? I can't find anything about that....

Arrie

You need to talk to someone with the Xentry or whatever they call it. Dealers and indy MB shops have it but I don't know if there even is a setting for idle speed? You might have engine speed sensor problem...? That would be an easy fix, I think.

Someone else here in the forum probably knows how to replace the engine speed sensor. I have not worked on that on this car. I did replace the sensor in one of my previous vehicles and it was very easy and low cost repair.

Mud

Live data (most inexpensive scantools can provide this) should be reviewed, from initial cold start (open loop) through warm-up into closed loop.

Just because a hard CEL hasn't been commanded by the ECU doesn't mean that the engine may not have any issues. The ECU works within ranges on most sensor input. If range hi or lo setpoints are exceeded, CEL will be commanded on and freeze frame data stored. Your car may still be within range , but be close to a hi or lo set point that's causing the issue. Looking at and understanding what the live data is showing can help give a direction.

I suggest looking especially at short/long fuel trims and O2 sensor readings. I know you said somebody looked at it but it still sort of sounds like a small vacuum leak. Short term fuel trim can help point to possible vacuum or fuel delivery troubles. Besides the usual looking at hoses and sealing of air housing to TB, the shaft seals on the intake tumble flaps can be a sneaky culprit.

Windwagen

Interesting... I'm going to ask my mechanic if the idle speed can be adjusted. I do have icarsoft MBii so I'll go see if I can spot anything with the O2 sensor signals.

Btw - thanks for commenting on this old thread. I'm not the OP.. Nobody has looked at my car (yet) regarding this issue. It's not a huge deal, but I'd like to fix it.

Some notes:
When the car is totally warmed up - 30 mins+, It's smooth at idle. (I should note the idle speed)
In hot weather - it will idle smooth, even a cold start. Seems like this happens on cooler weather only.
Motor mounts - seem way to solid and there are ZERO vibrations while driving. Plus the above.... seems to eliminate this as a cause.

Windwagen

So - Our cars have the wideband or A/F sensors. I can see some action. It doesn't switch lean/rich like an o2 sensor but the voltage ranges from .0.95 to 1.08 roughly. I took a video if anyone wants to see. It's actually pretty warm today so the idle is smoother than cold days. I thought I'd check some other data and I noticed the intake air temp is reporting much higher than what I'd expect. It says 32C...but the actual temperature is more like 15C. The coolant temp on the scanner says 102C but the gauge on the instrument panel is reporting 60C.

I'll check again in the morning before I start the engine and see what it says.

Windwagen

Before starting the car

MBii
Intake Air Temp is 17.23 C.
Outside Temperature 7.51 C
Coolant 67 C

I think there is something wrong with the MBii - I'll check with icarsoft. Later, I thought t check using the OBDii function, but now I've driven for over 30 min

OBDii
Coolant 105 C - seems right
Intake Air Temp 22 C - still too warm, it's

MBii
Intake Air 25.48 C
Outside Temp 8.26 C - seems right
Coolant 154 C - way too high!!

I have another OBDii scanner, I'll check again tomorrow to see what it says about Intake Air Temp. Do you know if the gas E350 has one of these or if it's part of the MAF sensor? I can't seem to find a solid answer. Bluetec seems to have a separate sensor.

Mud

Those values do seem a bit strange, good idea to verify with another scantool.
I believe IAT and air flow rate are combined into the MAF sensor. You want to verify that both IAT and MAF are reading correctly.
Incidentally the O2 Lambda reading appears to indicate rich mixture. Perfect 14:7 air/fuel is 2.25v to 2.5v depending on whose chart you use, although voltage varying is normal as the sensor reads O2 levels, lower voltage is reading rich, higher voltage is reading lean. However a consistently lower or higher voltage is indicating a possible issue. Assuming your reading is correct, engine may be running rich. Might want to verify that engine is indeed going into and staying in closed loop, then looking at running fuel pressure. Open loop (engine cold) stock programming usually runs richer, then fuel control shifts to O2 input as engine goes into closed loop.
If loop and pressure are ok, it may point to a leaking injector allowing more fuel into a cylinder, causing rich condition. Another check is with oscilloscope to check injector pulse width - all should be virtually the same. But most home diy don't have one, just mentioned as a check to help narrow to a particular cylinder. An injector with a different PW has a problem.
Just thinking through this some more, a verified high IAT reading can cause the engine to pull fuel ( you'd think it would be the opposite) and can also cause the ECU to add more EGR flow. Both can lead to rough running. The ECU reading a faulty MAF reading can command more or less fuel, again leading to rough running. So MAF reading should also be checked.
So my guess is leading to a possible fuel issue. Not saying I'm right just mulling over the info. Some further checks as mentioned may help to verify if this is a feasible direction.

nota_amg

Idle is 600rpm(on my e550) and there is no adjustment.
The wideband O2 sensors/systems our cars utilize WILL NOT sweep like a traditional 4 wire system would. you should only see minor movement(specifically after blipping the throttle, etc...), not a wide sweeping voltage like in the old systems.
The MBii has "Smooth Running" check and should show injector issues(in the Engine category under data stream).
I believe there is a misfire counter in the MBii as well, but cannot verify that at this time.

Have you run a full scan on MBii(with the correct model chosen) and look at your engine stored codes(Mercedes specific mode, NOT in OBD mode)? Are there are any stored misfire codes?

When you are checking the IAT, are you moving/driving, or setting in place at idle? It does seem weird to get different readings though. Are you sure you are entering the correct 6 digit model number in MBii(212.xxx)? I know there are several for each chassis/model and choosing this incorrectly could cause issues with data acquisition

Windwagen

You know - I do have a scope!! It's under the floor of the trunk right now - I use it for work.

I'll note the MAF reading tomorrow too.
Smooth running check? I'll have to try that.
No misfire counts
I'll have to do the full scan too.

A little history. I bought this car used with 70,000 miles and it had the rough idle all along. Again - it's very smooth once fully warmed up. Other cars I test drove were smooth..HOWEVER, maybe they were already warm when I test drove?? When I bought the car I figured I'll swap the engine mounts...problem solved. I even bought some mounts from eBay (wrong ones). But over time, I got thinking that bad motor mounts would have OTHER symptoms. When the weather got warmer, the idle is always smooth so I forgot about it until the fall. That was 2 years ago...and still the same.

Am I just too picky? Maybe this is normal? It's not wicked...my wife wouldn't notice. I can feel some vibration in the steering wheel.

Windwagen

Ok - car sat for 8 hrs.... Other OBii scanner has similar results. The intake air temp shows somewhat warmer with the engine OFF. I started it and revved the motor a bit...thinking more cool airflow. The temp dropped slightly. Now I'm really confused. What's a normal MAF reading at idle?

thanks

dwalz914

Windwagen, did you ever figure out the vibration issue?

CaliBenzDriver

The engine vibrations comes from both banks running on different diet.

Something is throwing off the precise AFR mixture needed for running conditions: either air or gas!

Once you know you don't have: a dirty MAF, intake leak, tired fuel pump, leaky injectors, tired alternator, split mounts, old sparkplugs/coils... you can consider the 2x UPSTREAM LAMBDA SENSORS.

They are closely monitored by the ECU so many folks including myself, assume they are all good until an O2-Heater code pops-up, not so!

Actually aged "O2"(Lambda) give lazy response to mixture changes but under the radar so the computer sees what it wants and never complains. ECU gradually fills up its fuel maps with lean values for each bank. You get the perfect old-car feel: less power, more heat, engine vibrations, poor pedal response, weaker accelerations, longer cranks... enough to put you in the mood of trading your problem away!

The culprit is likely the tiny passages in the sample chamber that gradually get plugged up or contamination of the sensing surfaces... all yielding a lazy sensor around the 100kMi mark (70...130k)

A healthy fuel map is super responsive to small pedal input with good torque at 1200Rpm when both banks are balanced.


+++++
Don't go overboard changing downstream secondary sensors. They only monitor cats have not been melted by rich mixtures.

Jerry Easley

I am reading this 3 years later, and find it very valuable. For a problem on my daughter's 2002 VW New Beetle w/170,000 miles. Very insightful about aging 02 sensors which do occasionally set codes but when checked seem otherwise OK. Had already gone thru the list of 'you don't have' but not considered these.

Thank you

CaliBenzDriver

In addition here goes the consumable chain tensioner:

Another favorite wear item under the radar is the loose chain tensioner. It alows the camshaft closest to it (Intake or exhaust) to woble left-right due to low chain tension. That screws up timings and mixture sensed by O2.

Instead of using a good ratcheting tensioner that can never back down, we see a simple spring and oil seal. By the time the oil seal leaks enough of the usefull oil pressure, the plunger is allowed to travel up/down (no ratcheting!).

The tensioner is barely there and the camshaft is allowed to counter rotate using chain slack.

Oil seal rubber was made sentive to oil chemistry, in particular old oil acidity. Some engine experience this gentle failure early/late. The timing jitter gradually de-tunes the engine out of balance into a checker.

Do reset ECU after replacement to relearn fuel map from stock values.

If you want to change cheapo tensioner go ahead around 60kMi -

Many people get stuck on mount replacement for vibrations and ignition for misfires - German engineers love to invent new trends to stay on top of their game

Arrie

After very recent experience with my S550 I would replace the cam shaft position sensors first if engine has "rough" idle. Made a huge difference with my car,

There are 4 sensors as there is one for each cam shaft. My sensors cost $84/piece and they were super easy to replace. I believe this design is the same in all MB V-engines.

You can buy just one sensor and use that to replace each one to see which one is going bad.

I have change 3 of them and will change the last one too as my car is 10+ years old. Like I said, this simple repair made a huge improvement in how smooth the engine runs especially at low speeds.

Amarnation

The op has the exact same problem I'm having. Low rpm engine is vibrating and when its hot it all goes away. Did op fix this issue ?

also question about the chain tensioner. Is that a hard job to replace?

CaliBenzDriver

Difficulty: light to medium.
The secondary chain tensioners are a lot easier to access than the PCV cramped at the engine rear.
The idle vibrations you're feeling are random misfires. Many things can contribute to that.
Basics are first!
Make sure you're not dealing with old spark plugs with wide gaps or old serpentine belt... The exact spark timing is extremely precise.
The engine computer is very competent in optimizing combustion parameters. Anything that introduces randomness in the crank smooth rotation hurts the computed cylinder combustion.
The ECU keeps track of combustion outcomes to calculate futures settings. It knows not just fuel map, also jitter variability to run the leanest near misfire.
That intelligent software is why we purchased a Benz. It is the best Bosch's development there was back then during production.


> Can't go wrong... :
Any of the conventional repairs you do to your engine is one you won't need to do next.
Pick from the list of contributing factors, you're guaranteed it won't be a waste of ressource.

Gmon777

did you ever solve this problem I have the exact same issue with my car? I replaced all spark plugs all coils and new trans mount. I can feel vibrations in all gears and once i increase rpm the vibration is gone.

juanmor40

Are any DTC codes from the scanner?

Gmon777

There is no check engine light or codes

juanmor40

Any vibration in Parking or Neutral as you increase the RPM? The idea is to isolate engine, transmission, and driveshaft vibrations.