transmission acting very weird!

[e420A1]

i recently bought a 97 e420 (month or so ago) with 150k miles on it, and i initially noticed no problems. few days ago on a cold morning (27F) the car started normally i took a short trip and on my way back the transmission got stuck on third gear and would not upshift no mattet how much i revved it. I tried to manually shift the car or put it on N and back on D. it did go to neutral but when back on D it stayed on third gear. i stopped the car, turned off the ignition and turned it back on and it shifted fine. well if that wasn't weird enough, the next morning (just as cold) i drove the car and i noticed that the shift knob was hard to shift between D and 4, before it needed only a simple nudge. then after about 30 minuted of driving it would become significantly easier to move. the transmission was shifting fine at all gears though. i remenberd that that had happened the day before too. also on that same day when trying to back up the knob got stuck and it would not engage in reverse (it would move to the reverse position or park but would not engage). the car was still engaged in drive. then i forced the knob back to drive and i heard a pop originating from the top of the trans (no internally i think). from then on i could shift the trans in all positions and it engaged normally. So here is my delema! WHAT THE HECK IS HAPPENING TO MY CAR! i drove the car this morning and it drove fine, temperatures where in the high 40's. I'am speculating the the AT fluid is in desperate need to be changed. i don't have the updated service records for the car, so i don't know if the trans has been serviced before. any ideas! your help is greatly appreciated .

[Nate]

Check your ATF fluid. What I do is get a white rag, with no crap on it, and get a drop of the fluid from your car on it. Then I put a drop of new fluid next to it... If theyre the same, good, if not change the fluid and filter... BUT I'm not sure thats the problem, but you should change it anyways if you dont know the records.

~Nate

[e420A1]

i checked the fluid today, i didn't have the dipstick so i went to home depot and bough a length to steel cable and it went in perfect. i was surprised to see that the fluid looked clean. it had a yellow brownish color. i couldn't verify if it had any metal shavings int it. it smelled funny but i don't have the new fuid yet to compare it. i ordered everything i need to get an AT oil change.
i was reading through hundreds of posts on this site and others and found out that somone olse had the same problem
his turned out to be the control unit ECU . it tells the transmission when to shift (these cars have an adaptive shift alogarithm). the problem resulted when the oil leached into the board shorting it out. it seems to be a common problems among V8's equiped with the five speed transmisson.
does anyone know where this board is located. and is there any way to fix it without having to replace the board and harness!?

[e420A1]

Questions
-is the board salvagable once it malfunctions? i.e can i use a degreaser like acetone or something to dry the board.
-does the harness have to be replaced: can AT fluid leak through the thick insulation and short the wires?
-where can i obtain the board from? and does anyone have a part nummber.
-is this a do it yourslef project or should i leave it to the pro's
-would a malfuntion of the ecu board cause the transmission to break and how would i know if the trans is damaged.

i know i'm asking a lot of question but i trust that you guys are very helpful and you wouldn't mind me doing so.
any feedbak would be great.

[t walgamuth]

change the fluid and filter. find a dipstick for your car. make sure the fluid level is correct.

with out a dipstick you wont know anything. starting to take mechanical things apart will just waste money. do the basics first. 80% chance this will solve your problem.

tom w

[JBR]

I am no MB expert, but yellow brown trans fluid? I'm from the old school and yellow brown was not good back then. I agree as stated above change fluid and filter. But also the first thing that came to my mind, was ice build up under car restricting the trans linkage. Just a thought. Good luck

[Nate]

I missed that part about the yellow brownish fluid with a funny smell... CHANGE IT NOW

A quart of atf (for compaison)is at most $5, a transmission is a bit more than that

~Nate

[e420A1]

thanks for all the responses guys. i already ordered 9 quarts of mb trans fluid in addition to the dipstick, filter and gaskets for around $140. the fluid wasn't really brown but it is a yellow with a shade of brown to it. it wasn't red though. i don't know if it smelled burned or not as i don't know what the fluid should smell like, if it has a smell at all.
there where no ice buildup that morning and i had droven the car for a few miles before i experienced the symptoms.
i have been driving the car for a few days now without any incidents. i hope it stays that way. i definitly don't want my investment in this car to go down the drain.
the incident i had seems hauntingly similar to the one discribed in this thread on another website
http://forums.mbworld.org/forums/showthread.php?t=85708&highlight=e420+transmission+Problems
i sure hope that mine only requires the fluid change.
oh you want to hear something funny: i was at the chrystler dealer today returning my jeep libery and i asked him how much he would appraise my merc for a trade in. he said $3500 . i almost fell over my chair laughing. he claimed that's because it has high miles and the sunroof doesn't work (the dumbass couldn't even work the switch) lol
any other views or thoughts!?

[e420A1]

OH! I i just got the dipstick and i went out to measure the oil. the car had been sitting for about an hour and the level was on the lower mark (cold). i noticed a couple diturbing things too: the oil had metal shavings and what looked like gunk (very small black deposits). should i start feaking out now!
i bought the car for $ 6k (good deal don't u think) knowing it had a few cosmetic flaws (some rust spots repair) but i never planned for a trans overhaul. should i dump the car for a better one or should i keep it. help please, :wtf: i'm freaking out!
what should I do?

[Hatterasguy]

Change the fluid. Drop the pan and see what you find. 150k and any maintaince records? Let me guess orignal fluid?

Since you got the thing so cheap even if you raplace the trans you are still way ahead.

[e420A1]

Originally Posted by Hatterasguy

Change the fluid. Drop the pan and see what you find. 150k and any maintaince records? Let me guess orignal fluid?

Since you got the thing so cheap even if you raplace the trans you are still way ahead.

i'm guessing that it is original fluid too. the previous owner didn't even know how to open the hood lol. i will change it as soon as i get the new fluid in.
is metal shaving a sign of failure or is it normal wear and tear for such a mileage?
what do you think the car is worth considering everything else is in working condition?

[e420A1]

correction the levels where at the lower 80 mark. i guess that is fine.

[Hatterasguy]

With a working trans probably almost twice what you paid for it. I have seen some pretty beat W210's for $11k.

Metal is a bad sign the pan should be clean.

[JBR]

As far as I know the yellow fluid is bad, Good guess is that it is original. When you checked the level, was the car running? If the car was not running the reading should be real high on the stick. If the car was running it should be between the lines on the high side. If it was me I would change the fluid and filter then run a few hundred miles and change it all again. Reason being it sounds that this fluid is in real bad shape, you want to get it all out and all the sluge and metal filings. Good luck

[andmoon]

How much junk can drop in an open dipstick hole?

Don't freak just yet. I had a vw vanagon that had metal bits in the transaxle for over 100K miles. Never knew where it came from but the thing didn't die. Change the fluid and go from there. If you are going to replace the tranny w/ a used one (in worst case) then just keep this one running!