420SEL owners manual + transmission questions

Try ebay for used owner manual... or you can try MBUSA and ask...

As for your transmission, it is a 4 speed auto tranny... however it starts off second gear so you only feel 2 shift.

4000RPM is too high for 65MPH... something is wrong... can be as easy as the transmission shifter bushings underneath the car... does your shifter feel sloppy? If yes, then you are probably engaged at 3 even though you had it on D.

The dash light you describe sounds like the indicator for a blown bulb

-- such as a headlight, parking light, turn signal, backup light, etc. Any bulbs out? Don't forget the three brake lights and the backup lights. On my 1987 420SEL it also comes on occasionally for no reason, just to keep things interesting.

On the headlamp switch itself, pulling out the knob one detent (after the lights are switched on) will activate the foglamps; there's usually a yellow indicator light either near or on the knob itself to let you know the fog lamps are illuminated. Pulling the knob out to the second detent activates both the front foglamps and one rear foglamp, usually indicated with a small red light on or near the headlamp switch.

If the yellow light you're seeing is up near the other warning indicators, and only comes on with the headlights, then there is probably a bulb out, or a bulb with a corroded base that's intermittently out. Be sure to check the license plate bulbs -- and if everything is looking okay, it might be a corroded socket on one of them. It's usually something obvious with the lights, and many people forget to check the license plate lamps.

The yellow Check Engine light is usually an emissions-related problem, like a sensor going bad or an overfilled gas tank, and is unrelated to engine blowup. The water temp and oil pressure are usually the indicators of engine trouble, but that's extremely rare to have to worry about. If you're on the road and something happens to make you wonder whether you should pull over or keep going, call the 1-800-for-Mercedes number (1-800-367-6372), and they'll connect you with someone. They'll also send Roadside Assistance to you with some fuel, to change a tire, or to install a new battery. Roadside Assistance is available to all MB owners, whether new cars or old, and there's no registration or subscription needed to use it.

If the yellow "dummy" light goes on only when the lights are on, it might mean a burnt or loose bulb. Good luck.