auto transmisson question

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Dec 2, 2004 | 08:22 AM

DIMITRIAR

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From: Perth (Aust)

300CE-24

auto transmisson question

my car is a 300ce-24 with 5-speed auto. I am occasionally experiencing a slight flaring(rise in revs) between 2nd-3rd on a light throttle.Could someone please tell me why this is so, and what i need to do to fix this problem.I suspect it has something to do with the valve body.

Dec 2, 2004 | 07:08 PM

13benz

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98 C-230

sounds like the fluid is a little low, or the clutch packs are getting worn. i would check the fluid first. if you suspect a valve body malfunction, a good transmission shop can attach pressure guages to most auto transmissions, i don't know about benz i have never had problems with mine yet, but i bet the threads are there for a guage. good luck.

Dec 2, 2004 | 10:20 PM

DIMITRIAR

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From: Perth (Aust)

300CE-24

thanks for the reply 13benz,another bit of info i can give regarding my problem is that up until now (145,000km's)i had never experienced this flaring till the benz service centre,removed my valve body to inspect(for an unrelated problem)and then re-installed it,apparently without touching it's inside's.

Dec 3, 2004 | 12:32 AM

13benz

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98 C-230

i see why you would suspect the valve body now. but i doubt the problem was unrelated. i haven't ever had a mercedes transmision apart, but i have had a few american ones apart. under the valve body in a chevrolet, there are check valves, (they look like bb's) maybe one of those fell out, a loose or missing bolt, could be a lot of things, seems odd to me that they would take the valve body out. why would they take that off? tearing into anything that complicated that isn't broke is just asking for trouble. there's also a servo and some sensors in there that are controled by the computer. input shaft speed and vehicle speed are calculated sent to the computer, the computer chews on it and spits back the command to shift. but it will set off the check engine light when one of them goes. the computer can cause flareing by taking to long to complete an upshift. i would still check the fluid, the difference between add and full is next to nothing, so i would double check that first. i would make sure the shop that pulled it off knew about the new problem, if they don't/can't fix it, i would take it to somewhere that could. i hope it works out cheap, was it filled back up with synthetic fluid? all i can do on this side is guess.

Dec 3, 2004 | 03:55 AM

DIMITRIAR

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Joined: Apr 2004

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From: Perth (Aust)

300CE-24

thanks benz13. i'll have to take it to a transmission specialist now,as i have since relocated from one side of australia to the other.But the reason they took my valve body out was because of a problem i had where the gear change was by-passing 4th gear ,and so just going from 3rd-5th.After replacing the trans computer module,& solenoid valve without any success,there other solution was to put a brand new valve body in.This also made no difference to the problem and infact made things worse as this new valve body accually flared every time (2nd-3rd)on a light throttle.So i basically said,put my old valve body back,so at least i could enjoy my car without the flaring,and that the 4th gear problem, i would just continue to battle on with.This is where i'm at now.An occasional flare (2nd-3rd) & a missing 4th gear that will always begin to work normally for anything up to a week or two ,when they clear the codes of the computer.This particular problem has now been narrowed down to being a voltage electrical type of problem somewhere from the battery to the transmission,because after replacing my old battery with a new one and clearing the codes,the 4th gear problem was good for about 6 weeks,instead of just a few days to a week or two.Hope you can make something out of all this .

Dec 4, 2004 | 09:29 PM

13benz

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98 C-230

i hope it works out to be something that isn't to expensive. i don't know that much about the computer controlled automatics, but maybe this link will have some relevant info for you. your mercedes dealer will probably charge more than a independent shop, but they probably have seen this problem before. a wiring harness update was issued on some of these cars, so i'd ask about that too if things don't work out, good luck
http://www.babcox.com/editorial/us/us90224.htm