Hi all,

I'm trying to help my mom by working on her old 1994 S320, 5-speed automatic. It definitely needs some love. Mileage at 170k though is not that bad for a 94.

I can't find much online about this model (Due to how old it is), and I normally don't work with Mercedes as much as easier Japanese cars, so I'm here for some help. From what I've read so far, for example it's the type of vehicle where you don't want to use very many non-OEM parts/fluids.

Are there by chance any DIY's on this site for this old of a model? If not, what manual can you guys practically recommend to me between Chilton, Haynes, or the Benz FSM itself to get more intimate with under the hood?

The transmission runs a bit rough, kind of like it skips a gear, or can't fully engage into the gear bands on a given gear. I was hoping some new fluid and filter might help, but it might really just need a rebuild.

Other than that, it runs pretty solid. I'm sure it could use new spark plugs and various tune-up stuff like that. The only thing I know she has maintained on it is the oil changes. Unless the dealer has been checking other stuff and given her XYZ recommendations (I'll ask her), I'm sure its due for tons of various items.

Thanks

check plug that runs to computer under the hood,it can cause ATF to get in computer box.The conductor plate is a maint. item too.I saw a five speed run to 320,000 miles before rebuild.There are no Haynes books.Joiin Mercedes Benz forum for the w140 group,lots of info.Pre 96 models are known for their wiring harness crumbling.

Now now scanner won't work, it'll turn over but will not start. I think the computer looking thing is an ECU or an amplifier? Is it possible to dry with a hair dryer? Oops, didn't mean to put here, sorry.

What,you have wet computer,You need to get electrical contact cleaner.It will evaperate the water faster.Do it with battery disconnected.