1985 300D with 200K miles will run for weeks with slight to no coolant loss, at about 80 degrees C, then for no apparent reason, lose a bunch of coolant, & begin running hot. No noticeable leak.

One nite last Fall, it went down to 12 degrees F, and later noticed a pool of coolant on the ground. Put a sample in the freezer, & concluded it just barely froze, put a richer mixture in the car, warmed it up, some leaked, & put the car away for the winter.

Just filled it up with water/coolant mix, it took over a gallon, and started it up and ran it about 1/2 hour. No coolant leaked, resevoir went down little or none, temp guage at a cool 80 C.

What gives?? Are the freeze plugs spring loaded and fix themselves?
Izzit the pump? Baffled !



Several 300D's in varying states of decay, and an '81 240D 4 spd with 90 K that is my favorite of the herd. All run on WVO, unconverted, summer only.