AlexN

Hello,
I recently purchased a 300E 2.8 (104.942) - new to the world of Mercedes ; I have some concerns about the transmission as follows:
- shifts roughly first and second gear change (less roughly the second) - cold and warm the same way.
- noticed it engages smoothly and immediately into R (cold or warm) but with a jolt in D (half a second delay approx.) when warm and smoother when cold in the morning.
- in D it vibrates (at stop sign in traffic) when cold and gets better as it warms up.

As I checked he trans fluid level:
- is above Max after a trip (engine idling and P) approx. 10mm higher than Max.
I hope to figure out if the high level determines the behaviour above and take steps to set the correct level - thank you for your suggestions

AlexN

As an update:
- I removed 250 ml of the ATF - no noticeable changes
10 min ride (went through all gears
- checked the level again, still looks higher than "max"

AlexN

Finally decided to change the fluid:
The local Mercedes dealer recommends Pennzoil


Should I use it?

mrbobby

Notice what color the old fluid is on removal. If you're changing the filter and cleaning the pan, look for any unusual material in the pan. Depending on the mileage a small amount of fine metal dust is normal depending on the last time the transmission was serviced.

While you're messing around under the hood check the oil level/color and radiator level/color. Either someone dramatically overfilled the transmission or something else is going on here at the same time. Analyze before running around and changing this and that. The trick here is to find the REAL problem and not an ancillary problem. Good luck with the repair and welcome to Mercedes and to the Forum.

Shadow5501

Shift quality is controlled by a vacuum signal to the transmission. High vacuum gives a smooth, soft shift. Closer to atmospheric pressure provides a firm shift. Tha vacuum source is the intake manifold. Quite possibly you simply have a vacuum leak.

Probably the engine shaking isn't related to the transmission. It could be any number of things - bad MAF, O2 sensor, tune up, vacuum leak, engine mounts. Have you pulled codes from the engine computer? Note that federal (as opposed to California) 300e 2.8 cars do not have a check engine light, so you cannot assume the lack of a CE means there are no codes set.

AlexN

Thank you for the guiding:
The facts:
- now car has 180k, the former owner saved money and serviced the car at Mr. Lube (I called them and ask what the trans service consists of and they only replace the oil and do nothing else, no filter change, no torque converter drainage).
- I replaced the oil myself with the oil purchased from dealer - Pennzoil: converter plus filter area - 6.1l approx. out and 5.8l in = now the level is at max at 76C temperature of the pan (reading from a cheaper laser thermometer).
found a greenish sticky deposit on bottom, some fine metal dust near the drainage bolt area; inside the filter same greenish color and looked dirty.
- reassembled and tested - a little better not shaking that much in D, slightly different sound, shifts a little better but not a dramatic improvement, maybe I am too demanding (I have driven a 190 2.6 330000km Benz before and remember it shifted smoother).
- while under the hood: oil level ok, clean, radiator level ok, color ok = still hoping to find the real problem.
- the high vacuum vs atm press vacuum i did not know how to check - starting investigating.
- the engine has an irregular idle but not severe, sounds like the older distributor cap ignition problem, but a little smoother.
- when started cold, idles high and oscillates two times 1200 to 3-400 and back to 1000 to 500 and stabilizes at about a little higher half way between 500 and 100 (maybe 700)
- I have to say I cleaned the throttle body (small black deposits) and the MAF sensor (was quite clean)
- I also replaced the wiring harness with a used one 2011 production date.
This is all I did to this one owner car hat I bought - the first owner maintained the car but at Mr. Lube type shops - after the warranty period expired: Benz dealer before.

So as far as driving experience goes, the car idles irregularly cold and warm, when you put it in R you get a smooth as can be engagement but in D it jolts forward a bit ( 0.5sec time ).
Cold starts I get the oscillating RMP as described and then it stabilizes.
While on the road it is silent except a little whining from the front low similar to the differential noises at older cars), has enough power for the 190HP spec and last downshift is noticeable, you can feel it but not too bad when coming to a complete stop.
I wish I could address these issues and be really proud of this white car

AlexN

pulled codes:
pin6 - 1,2
pin7 -1
pin8 - no blinks
pin 10 - no blinks
pin14 - reads 2,7,11
As a follow up, engine mounts look good.

AlexN

Transmission oil change:
- drained overnight all including torque converter
- 6.2l out 5.8l in gradually up to the max sign at 76C temperature read at bottom of pan.
- inside the pan had a greenish stcky deposit on the bottom and inside the filter, some dust like metal shavings towards the drainage plug
- filled with Pennzoil ATF DEXRON 2/3 compatible from the dealer
info: Mr. Lube did not change the filter just drained and refilled (overfilled by 1cm above max) - car has 180k km, that happened 6000 km ago
I asked them by phone what the procedure consists of and the confirmed there is no filter replacement included.
Results after new fluid in;
- less vibration in D but still a little jolt forward when engaging, smooth in and out of R, P, N
- while driving - smoother gear changes but not dramatically better (rougher compared to a 190 2.6 that I drove not too long ago I don’t know how they should compare as I am new to Benz)
- coming to a complete stop still noticeable jolt at the last downshifting - not bothersome just present.

Other information:
1) the idle is slightly irregular similar to the cars with an old distributor cap or like missing a spark now and then
When RPMs are higher runs smoothly
2) cold starts idles to 1200 then oscillates down to 400 - up 1000 down 500 and settles somewhere between the 500 and 1000 mark - warm starts fine without oscillating.

I replaced the wiring harness and cleaned MAF (was clean) and throttle body inside from above (some dark deposits there)
It improved the idling - it used to happen when warm too sometimes.
I will investigate to see how these symptoms are related or not - hope to help the white Benz to become as healthy as possible at 180k km.

mrbobby

Sounds like vacuum leak now

Shadow5501

Do you mean no errors on pin 8? That's the main ECU error codes. Errors 2 and 11 are common on pin 14, but error 7 indicates a CAN bus error. I am thinking the electronic throttle wiring harness is bad - it suffers from the same wiring degradation as the main engine wiring harness on these cars.

List of blink codes: http://www.peachparts.com/shopforum/...-pin-14-a.html

AlexN

About error 7:
when I tried to clear the error it did not work (error was still there after deleting it) - the rest of the errors were cleared.
After driving codes came back.
No errors on pin 8 but:
there was not a "one blink" confirmation of no errors, just no reaction no blink at all (if that makes a difference I don't know)
I watched a video of repairing the throttle body wiring and it looks challenging to say the least.

AlexN

While under the hood:
MrBobby suggested to check the coolant level/color
I checked first time and seemed ok, now I remember when purchased the car, the coolant color was purple-ish and totally clean and now it looks dark yellow (not even 500km driven since purchase). It is transparent to a degree, I will siphon some out and post a pic. No visible patches inside the reservoir.
Head gasket and water pump were done 2005 100k km ago (now 180k km) within warranty at the dealership (in file from prev owner).
Last coolant change at Mr. Lube, they do not mention the coolant type on invoice.
Should I worry should I change the fluid?

mrbobby

My concern was transmission cooler failure that allowed transmission fluid to be contaminated by the coolant. If the coolant level was low and the transmission fluid level were high I would suspect a bad radiator allowing the 2 fluids to mix. This will eventually (not a long time) result in the destruction of the transmission.

AlexN

How does it look/feel when the two fluids mix?
I guess it is hard to tell just using the senses versus chemical analysis at the shop. The coolant was/is not high before or now but it changed color, the transmission was over the max sign by 1 cm, fixed now.
Now it is good and the car shifts better and does not jolt when put in D and engages smoother.
So there is improvement but I can't compare - I guess these cars have a firmer first shift by design (info from other forums)
I will change the coolant anyway to have a starting point:
- the coolant type and the way to do it (will check this forum for guidance and info or step by step instructions)

For the other issues non related to transmission I will start new threads
Thank you all for the time you took to help!