jhillman

I have a 2 month old 2003 C320 sedan. I have noticed some strange behaviors from the transmission and was wondering if these behaviors are normal? Also, FYI, these issues have been noted when the car is already warmed-up, not just when cold.

First, the transmission often seems to shift funny from 2-3 and from 3-4 gears under moderate-to-heavy acceleration. Just when it disengages the throttle to shift to the next gear, it will hesitate for a moment and then kick-in semi-abruptly when accelerating into the next gear. This is best described as a stutter. This stuttering sounds like engaging the next gear, then backing off very briefly, thenly re-engaging. Almost as if I killed the throttle right when hitting the next gear, then reapplied.

The other problem I believe is also related to the transmission, or maybe the throttle management system that works in conjunction with the transmission and shifting program. The other day, I was crusing at about 20 mph and accelerated sharply to get onto a freeway on ramp. I reached the top RPM range (far from red line) for the gear I was in (probably 3rd), and car went to shift on to the next gear. When it went to shift out of 3rd, it was like someone shut off the ignition (the throttle was cut off completely for about 1.5 seconds and the car slowed abruptly) though I still had my foot on the gas pedal. When the throttle and transmission re-engaged, it was in the next gear and accelerated rapidly. I've experienced this twice since I've owned the car.

Has anyone had these types of issues? Any suggestions or thoughts on what may be the problem? Of course these are intermittent problems, so I'm concerned they won't be able to reproduce them while it's in for service.

Jerry MB230K

suggest you take it to the shop .. and don't hesitate (like your car does)

jhillman

So has anyone had these issues with their transmission?

sirenebekim

when i start mine cold in the morning it runs in first and second gear untill i slow down at the stop sign, then it shifts fine.... It hesitates to shift out of second causing the rpms to be like 3500 at 20 mph... Odd, I asked a mechanic and he said there is something wrong, but the computer doesn't show anything? My car has 93k miles on it, 2nd owner... I'm guessing if i get my tranny flushed it will fix it... Any thoughts? Thanks!

dmatre

If the engine is cold, it will run in a lower gear (higher rpm) in an attempt to bring the cats up to operating temperature more quickly. This is normal. Once the cats are up to temperature, the transmission then shifts normally.

(I'd consider changing mechanics)

everycredit

The manual agrees with you. It states that this is the normal process for a cold engine to heat up the catalytic converter. This does not harm your engine.

mleskovar

Not normal. I have read where problems are caused by the TCU getting drenched by trans oil migrating up the wiring harness (the TCU is located under the passenger floor carpet beneath a steel plate?...haven't seen it myself though). One poster suggested that first pulling the TCU connector/harness electrical connector out of the transmission and if fluid drips from the harness the seal is probably bad. Have you checked your trans fluid level?

coin

My car experiences the same problem as stated below. I just got my car back today from service. The invoice states that "Short Test Code P2203. Internal Electrical Fault W/Y3/6N3. Speed Sensors. Replace ETC Control Plate in Trans. Clear Codes."

I am not sure if this means anything. Anyone ?

raklert

the best thing that you can do when it comes to AT tranny is to check the AT oil if they still good or not. Usually, changing AT oil help cures a lot of AT problems such as shaking and slow shifts. But in your case, you should take it to the dealer and insist that the problem be fix. When the syptom of the car is intermitten usually relates to electronics issues, not mechanical. A STAR should be able to verify that for you. Anyway, Keep us inform man.

b3d_sage

Call Park Place, ask for Steve in service. Tell him you're on mbworld and David with the purple C320 told you he'd take good care of you. There is DEFINITELY a problem with this car.

How many miles are on the car and do you know if the transmission has ever been serviced?

Philip317

Please refer to my message under the heading of R230 transmission problems

See what is known to MB already about their faulty transmissions

MARC64

Im trying to buy this car with 267k (2003). ..but When starting car sometimes does car will rock when placing in gear and result is when u get out on road will not get out of 1/2 gear or sometimes after start will go into gear smoothly and never have a problem! ,,,PLEASE NEED HELP ASAP...!!!

Glyn M Ruck

Does the holding of 1st & 2nd gear only happen at a cold start? The vehicle is supposed to go into high idle & hold on to low gears when cold to heat the Cats more quickly. This is normal behavior. If it does it hot then something is wrong.

Is there any service history on this car. Has the transmission been serviced every 39K miles or 60K Km's? If the transmission has not been serviced you are taking a big chance. At that mileage you are getting the car cheaply I presume. A major transmission repair could cost what the car is worth.