speedyc43

Wanted to know if this is normal. I only bought the car about 2 months ago and it drives fine but sometimes it feels like it shifts really early and it almost throws the gear in. Once it warms up it generally gets a lot better. I bought the Eurocharged TCU tune but I'm not sure I want to install it just because I don't want any additional stress on the transmission. Any thoughts? Also wanted to mention that I did have the fluid changed at the time of purchase.

sufyaanahmed

Car does the same thing when for the first 5 minutes of driving usually just first gear wondering the same thing as you also had my Trans fluid changed i dont think it's our tune

FinanceMike

My car does the same thing. On a cold start, it short shifts into second (does the same in C mode). Transmission has been checked out fine by the dealer and independent mechanic and I've had the fluid and filter changed twice during ownership.

If I let the car idle for 5 minutes before I leave my garage, it greatly reduces it or it doesn't do it at all. Mine will only do it on the first shift of the drive, never after that.

p30amg08

Mine has a similar issue. When cold either in reverse or D, car seems to hesitate. hard to explain it's just Jerky... E63...

cahiil55k

It's normal. Since owning the car in '09, it often refuses to downshift to first gear when transmission is cold. If I force first gear by using manual mode or shifting down before the car rolls, it does the horsey hop/jerky/hesitating thing a few times before taking off unless I ease into acceleration.

speedyc43

Will im glad to hear its the norm. But im sure these beasts didnt run this sloppy out of the factory. If i bought it new id be dissapointed.

MaLicE

I was about to make this thread tonight too ha!

I also get if I'm at a standstill in d it seems to hesitate for the first few pull offs till warm... Was thinking maybe the cold weather makes the oil too thick?

sufyaanahmed

Mine actually started to this after I changed the tranny fluid and filter weird but after warmed up its drives fine

p30amg08

Exact same thing here, I'm thinking about taking it in to get looked at...

06cls55amg

same here as well.

phalen302

This is normal behavior. I pursued this issue extensively w/ my dealer, and their transmission master mech.

This issue is caused by not enough pressure in valve body in first start of the day. Function of valve body is to shift the gears - hence when there is not enough pressure to engage and un engage pistons - causes hard shift (hard jerks going from 1-2 and 2-1, If I remember it is K1 or K2 piston). MB usually update the transmission software - transmission pump comes on at full speed right after 15 sec when the car is started - help to get the enough pressure built up in the valve body and pump runs for 15 seconds. You will hear a slight pump noise if you have this "patch" installed. It helps a lot.

I live in DC and when it gets close to 32F - I had to warm up the car for 10 minutes or more for it to operate better - but with this new update, 2-3 minutes is enough to get the car going with out any really hard jerks.

This information is for 7 speed trany only.

ArmoE55

Best thing to do is let the car idle for a minute or two before starting to drive in the cold months; not longer than that, though. Letting a car idle too long isn't good either, but a minute or two to get the fluids and motor flowing well is always a good idea.

Actually, this should be with any car.

FinanceMike

Good info. Thanks. It only happens on the first start of the day, always after sitting overnight. The first shift feels exactly like putting a manual car into second gear right off idle. After the first run through the gears it never happens again.

Glad to hear it seems like a "normal" issue.

novae500

what dealer did you go to and how did you go about to get the tranny software updated?

phalen302

Mercedes Benz of Chantilly - SA is Lisa Rozier. I complained that this issue is unacceptable. Their tech escalated the issue with MB and updated the software. Also would like to add that I have MB CPO vehicle.

Shifter

I'm afraid you have no knowledge of what your talking about. The front pump is mechanically driven, software will not affect its pressure.

There is also many more variations in what can cause a harsh shift than it's operating pressure.

FromM3toAMG

Mine does it to from 2nd-3rd.. shifts fine just rough.. but only during warm up. My M3 did the same bs.. assumed it was just part of warm up process. I just had my trans checked by dealer.. its in perfect working order. the longer i let it warm up the less noticeable it its.

phalen302

Sir I am not sure if you are living under a rock or just don't know the topic - there are very large vendors out there who sell custom mappings which change the behaviors of the "Mechanical" items. If your statement was true - custom tuning business would not exist. Just an FYI to you - on MB, you can program a lot of things.

The information I posted above was given to me the MB mech at the MB dealership - not a self proclaimed MB experts.

In my mind the purpose of these forum/threads is build up a wealth of knowledge and not shoot from behind. The comment you posted has no value to this topic and please contribute vs. hate. Just 0.02 cents.

shardul

iTrader: (1)

all they did was clear all adaptations and reset them.

Shifter

This isn't about a aftermarket tune right? I didn't refer anything about that and I am well aware of them. What you posted about software changing the pumps pressure is factually wrong. Again it is mechanically driven by the tq convertor software can't change that specifically.

Shifter

Oh and not here "hating" just fixing incorrect info put out there.

ArmoE55

Be careful, man. He might mistake your E55 for a E320

phalen - good job wasting your time at the dealer while they cleared adaptations You need a vacation from the forum, good thing it's Thanksgiving week

Critter

Cars do different things when cold, first just be happy they start, allow the car to come up to operating temp, not just the coolant but all fluids. Then if you still have an issue well then maybe there is actually a problem but to expect a car to operate perfectly in cold weather just after a cold start then you are in dream land. IMO

speedyc43

Gonna have my car checked out at a tranny shop, cold weather is coming around the corner, and this ****ty behaviour is returning. Makes my car feel like a GEO when its cold. Anybody solve this yet?

SICAMG

I have been an automatic transmission builder for 27years and under no circumstances is it possible for a mechanically driven pump that is attached to a torque converter spin faster than the engine speed when needed. What is possible is the tcu will allow more fluid pressure to be achieved when needed.the pressure control solenoids act as a dam if you will and regulate fluid pressure or flow. I have built many of these and I know this as fact.