Change all the fluids, and pay close attention to the drained fluid (especially the coolant). Any wierd discolorations or particles are a bad sign. Drop a teaspoon of marvel mystery oil in each spark plug hole. Also, change all belts and hoses when you get the chance. Inspect every square inch for rust.


The 300SE is probably the most reliable of the gas powered w126's. Very far away from a problem car. But the 300SE in question may be iffy. Make sure you get a complete service history, and make sure it runs fine before you pay. The gas may be bad, I don't really know anything on that subject. I can say that I let my 85 Toyota Pickup sit outdoors in the sun for two years with half a tank, and it started up and ran just fine recently. Only thing I'm scared to touch on that truck is 4 wheel drive... I don't think it's EVER been in 4 wheel drive mode, so the transfer case and front differential are probably glued together.

Good luck!