Worrying auto transmission

[Devon]

Car is a 2001 210 Estate E200k.
A week or so ago I started the car and selected reverse - nothing happened. Waggled the stick back and forth a bit and then it engaged with a jolt. Reversed out, put it into drive and set off, only to find that it would not change up (I think) beyond second ratio. Eventually stopped the car, switched off then restarted. Gearbox worked fine. However I have noticed that now, when selecting drive or reverse from park, it engages with a bit of a jolt and the changes thereafter are not so smooth. In the past it always engaged with hardly a murmur and changes up and down were always silky smooth. Is this signalling that a serious problem is developing? By the way the car has done 80,000 miles and the ATF has never been changed. Also, probably a coincidence, but just before this problem occured I had switched the gearbox to W for a few days, just to try it out and then switched back to S.
Any advice gratefully received.
Mike

 

[dr benz]

hi may not be the end of the world, first check would be at the multi plug at the corner of the sump pan, for oil contamination if nice and dry then perform star tests

 

[television]

You must check the level of the fluid,,always the first thing to do

 

[rich.g.williams]

when you started up the computer found a sporadic fault and put transmission into emergency limp home which was reset by the ignition key

fault could be something intermittent in the wiring or electroplate or low fluid level may happen again

don't know why changes are different now, maybe resetting the computer has changed adaptation values

if fault recurs fluid top up or new electroplate/pilot bush may be all thats needed as malcolm says checking the fluid level is first thing to do

 

[Devon]

Today the car repeated the transmission problem I mentioned in my first post. This time I switched off, restarted and it was OK but with the engine warning light remaining on. I checked the fault code with my code reader gadget and it identified a transmission ECU fault (or something like that). I erased the fault code, disconnected the reader and tried to restart the car but it would not turn over. It has never ever refused to start before so I think the whole problem has been due to a failing battery. The car is now 8 years old and has never had a battery change so it seems likely.
S-A-M / U-N-I-T's post from 22-12-2008 seems to sum it up:-
http://forums.mercedesclub.org.uk/showthread.php?t=53230&highlight=BATTERY
So I will try a new battery unless anyone has a better idea.
Regarding the jolting when engaging gear, I also checked the ATF level as Malcolm suggested (using the curtain wire method / 5.6 cm etc.) and I was horrified to find that there was only a hint of fluid showing on the bottom of the wire. I am fairly sure I measured it correctly (pushed it past the first resistance until a firm stop was felt. Does this mean I am several litres short of fluid? Would the box work at all in that condition? I am also intrigued to know where the fluid goes in a "supposedly" sealed for life unit.

 

[octanejunkie]

Although gearboxes are supposed to be seald for life, this is a ridiculous notion. Auto gearbox fluid should be changed at around 30,000 miles if you want the transmission to last past 100,000 miles.

My old 230E was very reluctant to go up and down the box, very choppy changes, and was making awful fluttering noises. I dropped the pan on the box, changed the filter, and refilled with 4 litres(the gunge that came out was unbelievable).
The car still wouldn't play ball. Drained fluid again (2 litres from drain plug), and was shocked to discover the same black gunge as before! Drained fluid again, and the car was better, and quieter. Drained it one more time, and the car was perfect.

Anyhoo, with your transmission, there will be somewhere you can drain and fill from. D3 transmission fluid is less than £15 for 5 litres from GSF.
I'm sure fresh fluid will make the world of difference.
I'm not familiar with your type of box, but i'm sure someone on here will know the fluid capacity, and how to get fluid in and out?

 

[Devon]

I have now replaced the battery and the gearbox is working fine. It is amazing how a failing battery can cause such havoc via the ECUs in modern cars. Thanks to S-A-M / U-N-I-T for the battery tip.

I have also checked the ATF level again, using the curtain wire method but properly this time - twisting the wire as it is pushed down as per television/Malcolm's tip. The level appears to be OK. The ATF is not dark but a golden colour with no sign of "black gunge" so I guess that it is safe to leave it alone for the time being. As they say "if it aint broke don't fix it". I will have it checked again/changed at the next major service.

Thanks to everyone for their comments and suggestions.

 

[rich.g.williams]

if the battery is faulty (or its terminals are not secure) the voltage powering the various computers can drop to below a certain threshold during starting, the computers sense this and reset either because of lack of voltage or more likely for genuine safety reasons

in any event a faulty battery is bad news for an automatic car because there always comes a time when the battery won't start the car and the car is truly immobilised

 

[Devon]

Yes, the battery did give up completely in the end but fortunately whilst I was tinkering with it, checking fault codes, etc. at home. As you say, especially bad news in an automatic. Still, I guess I can't complain - 8 years and 80,000 miles from the original (Merc badged) battery. I bet the replacement (Exide from Eurocarparts) won't last as long.