wessamzeidan

Hello Guys,
I have a 2003 C230 kompressor sedan. I'm having a weird problem with my transmission. Its automatic transmission. If I'm accelerating smoothly, when it shifts from 1st to 2nd gear, the car jerks, like its pushed forward all of a sudden, and then everything goes back to normal. If I press on the pedal and accelerate fast, this doesn't happen. All other shifts are normal, its only the shift from 1st to 2nd gear when accelerating slowly. Any ideas what might be causing this?

Thanks in advance.

Glyn M Ruck

What mileage has the car done? Has it ever had a transmission flush, filter & oil change? Is the oil level correct in the transmission? You need a service dip stick to check this. Does your car have a Valeo radiator? These sometimes leak coolant into the transmission & cause problems such as this.

maccooper79

ah yeah I was having the same problem..this will follow with coolant lvel being low and b4 u know it...transmission oil inthe radiator...ie new radiator..well thats where I am at right now

holycaoAMG

i have the exact same problem, i thought i could live with it, but will it cause any real damage if i dont do anything about it later on???
I dont believe my car has done a transmission flush or change in oil or filter, that could be the problem. The jerk is definately there only from 1st to 2nd.

slammer111

Yup, another 2003 with the infamous 2nd jerk here.

The dealer reflashed the auto-module with the "latest version" (this was in 2006) which didn't solve the problem. One just learns to live with it. Not sure about your problem, but mine generally happens if I'm at high RPM right before/after the switch. For example, it happens often if I'm accelerating hard from 1st to 2nd, or I use engine braking going from 3rd into 2nd.

W203E35

I think it's a common problem. My 06 350 has the same problem. Its only when it smooth driving. 1st to 2nd it will be a rough shift. Even when its downshifting. But I have tried to put on comfort mode and not sport it doesn't happen (Maybe comfort starts off at 2nd gear that's why? )

I only have 20K miles.

khob

same problem here. Any preventing measures so nothing awful happens?

Glyn M Ruck

Yes it starts in second. This 1st to 2nd jerk you describe is not correct - It should not happen - Does your 350 have a 7G Tronic transmission?

W203E35

Ya, it's the 7G Tronic Transmission. When I come to a stop when it goes 2nd to 1st it feels like a kind of hard brake (It jerks).

I still have warranty till November i'll take it in. Also I still get this weird noise underneath the car. Lately it has gotten loud. It sounds like its ticking (tic tic tic). The ticking sounds use to be once in a while and now it's common. I remember Glyn you said that it might be the cat and it does seem like it because it is coming from somewhere in the middle.

Edit

The other day I met up with my friends at a coffee shop. When we were leaving I was making a right I didn't see a car was coming so I hit the gas hard so the car doesn't hit me. The next day my friends were asking me if I removed the resonator because a it sounded weird when I accelerated. If a cat does get messed up does it make ticking noise?

Thanks Again Glyn

Glyn M Ruck

There have been numerous software updates for the 7G - make them flash it with the latest & get the jerk on record before you warrantee expires. The 7G should be silky smooth - almost like it's slipping. My 5 speed is also totally smooth - The only way you should ever be able to catch these boxes out is snapping off WOT & braking hard just as the torque converter is locking up - this can give you a bit of a lurch but it's only if you drive like a real jerk & catch it out.

Yes the Cat can tick - Read PAPete's thread in this regard. How many speed bumps do you ride over? Speed bumps or severe potholes are Cat killers when the catalyst is incandescent. Usually a piece of the honeycomb breaks off.

W203E35

I live in Los Angeles, everyday I go through huge potholes (have to slow down). It makes going to work interesting counting how many pot holes I dodged. But once, it was the worst. I thought my axle was going to break. I hit this pothole in the worst way possible. I was going around 40MPH and didn't even notice the pothole then bang I hit it. I think that is what contributed to the excessive cat noise (since back then it was once in a while). I bought the car 1 month ago so who knows how many potholes the previous owner went into.

Thanks for your time and help Glyn I really appreciate it.

mtnman82

Another '03 owner here with the 1-2 gear jerk. I had my tranny serviced at ~45K Miles, but I noticed they only used ~5(maybe 6) quarts of fluid, so I doubt all was flushed. They did this under warranty becasue I complained about this same problem. Supposedly they also found an internal code thrown and replaced a relay in the tranny. The problem went away for a while, but now it's back. I don't have a Valeo radiator, BTW. Also, it does this mostly when cold (very rarely after it's warmed up).

Is there any way to check the tranny fluid without a dipstick? Can someone tell me the part # for a tranny dipstick so I can order one (also the part # oil dipstick if possible - I'll just order both at the same time)?

Glyn M Ruck

Transmission dip stick part# 140 589 15 21 00

Benz call it a "measuring stick"

mtnman82

Thanks, Glyn!!! (Might I bother you for the oil dipstick too?)

Glyn M Ruck

M271:

Oil dip stick part #120 589 07 21 00

wessamzeidan

So it looks like this is a common issue. My friend has a C230 kompressor sedan model 2004, and he has the same issue. I can live with it (although its really annoying) if it won't damage the trany.

Glyn M Ruck

The more I hear of this problem - the more I think it is the torque converter lock up clutch not releasing in time when coming up to a stop.

A jerk on change up from 1st to 2nd would be something else like the TCU not indicating to the ECU to retard timing at the moment of change up or a solenoid or valve body malfunction.

If oil, filters, levels etc are in good condition my first move would be to reflash the tranny software.

The gear ratios present here are always going to amplify shift shock issues.

W203E35

Hey guys,

I just got to work. 6:00 AM USA (Pacific). I was on the freeway driving and there was construction on the freeway. I slowed down to change my lane and when I accelerated (Not fast just regular accelaration) my car jerked (downshifted) very hard. I definetly need to take my car to the dealer.

P.S. I still have the 1st to 2nd jerk but it comes and goes. But the most I feel is when it downshifts from 2nd to 1st.

mtnman82

Thanks for the part #'s Glyn!!!

FWIW, I don't have the downshift jerking, just the 1-2 jerk mostly when cold.

W203E35

A little more that I wanted to add (maybe it will help out to get to the bottom of the problem for our fellow members who don't have warranty)

I was headed home (left a little early from work) and I noticed something else. Not only was the 1st to 2nd jerking but I felt the car was less responsive than it use to be. I believe it's a computer issue. I feel like the computer (proof that i'm a newb saying the word computer) isn't switching the gears correctly. So first it started with the 1st and 2nd gears jerking, in the morning on the free way slowing down then accelerating slowly felt like gear slipped and now it feels like the whole transmission even the throttle is lagging a bit. I press the gas pedal and there is a second lag.

Also I want to add that I have this rattling (sort of like a vibration) noise underneath the car and these couple of days the car sounded wierd. Which now comfirms Glyn's suggestion that it's the cat.

Thank You Glyn

I don't mean to sound like i'm attacking anyone or sound like a smart a$$ (just curious) does the transmission software get messed up or corrupt on it's own that's why it needs to be reflashed?

Glyn M Ruck

A car is a hostile environment for electronics - vibration, changing earth conditions, temperature extremes - voltage spikes & lows - electromagnetic fields etc can all lead to corruption of software flashed onto an EPROM

You might have some throttle switch problems but more likely a piece of Cat honeycomb moving around & partially blocking the exhaust.

BTW - you are most welcome to question me - then we all learn. Makes me get off my butt & do more research. I make many mistakes along with the rest of us. We're unfortunately not infallible. All I try and do is learn something new every day of my life.

C230 Sport Coup

The 722.9 tranny requires a complete flush at 35K miles per MB.
You can't check the level.
And it's also true, there was a software update to correct jerkiness.

So, do either or both as needed.

W203E35

Thanks Guys

Learning something new everyday.

The only field I am good at is computers. So if you guys need help with computers or software let me know

I dont know any other way to show how much I appreciate you guys taking the time to help me.

Thanks Again


Edit

C230 Sport Coupe, Thanks for the info on the 722.9 Transmission.
Glyn, thanks for your countless help with my newbish questions.

I thought I should give back to the community with my findings.

I found these on forums. It seems like people are having problems with the 722.9 transmissions.

Had the DTB done yesterday to fix the acceleration lag; and I can see only a miniscule, if any, improvement in the lag. I also ended up with an even harder 2->1 downshift out of the deal.


There is new software in the works to fix the hard 2->1 downshift in all 722.9 transmissions

In the mean time there is a new ATF 4134 (spec 236.14) P/N: 001-989-68-03-10 that is being recommended for all 722.9 transmissions. It it is supposed to run cooler, which might be a help for that hard 2->1 downshift; since on mine, it always seems to be worse when the weather and engine/transmission are hotter.

Price on the old ATF 3353 (spec 236.12) was/is $15.00/liter. The new ATF 4134 (spec 236.14) is priced at $32.50/liter.

Schedule to change at 40,000 miles.

Important info on changing Transmission Oil
The impossible part of trying to follow the WIS is that you must first refill 1 liter more than you drained. Then you must run the engine and cycle through P-R-N-D, etc. Then, with the engine idling in P, you must allow any excess oil to drain with the transmission at 40°C. The big problem is that, by this time, the transmission is already much hotter (~70°C); and there is a very big warning about the fact that too much will drain out, if the temperature is more than 40°C.

The only way to do this would be to refill and do the gear cycle. Then shut it off and allow it to cool over night. The next morning you could hook up the STAR, start the engine, remove the drain plug and allow it to drain while warming up. When it hits 40°C, close the plug and be done with it.

The engineer who designed this system must have been doing some very bad drugs when he did it. He certainly never worked on a shop floor or did this procedure himself.






In connection with my thread in the engine oil section, it seems like Mercedes is reducing the service intervals for their cars. From the 2009 maintenance manual, I noticed that Mercedes now requires a transmission fluid and filter change every 4 years or 40,000 miles, whichever comes first on all of their vehicles.

I guess the new 722.9 7-speed automatics need more frequent maintenance than its predecessors. The constant shifting must be putting some serious stress on the fluid.

Glyn M Ruck

+1 - We are jumping all over the place on this thread - The 722.6 (5 speed) transmission has a dipstick facility - universal stick PN above. The 722.9 (7 speed - 7G - Tronic) transmission has no dipstick tube & is filled from below with a special workshop device that ensures correct level.

Glyn M Ruck

Imagine exposing your old mainframe or even a midi to an automobile environment. Or imagine if Microsoft wrote the software for your car - multiple crashes on the way to work every day. - the thought is too ghastly to contemplate