My 18 year old son has been driving this 240D for a few months and today he had a problem. It stalled out at a light and he couldn't re-start. He was oblivious to the fact that it had run out of coolant.

When I got there, the cops had called a tow truck, who charged me $210 to tow it 50 feet to a parking lot.

Anyway, I limped it 7 miles home after refilling the radiator and watching carefully for overheating. It made it fine, although I swear it was having trouble shifting- I didn't take it over 40. Later at home, I drove it again, and it seemed to shift fine, so I don't know.

But here is the real question: the temp gauge is not reading. It is all the way at the bottom. And when I run the heater, it wasn't getting as hot as I'd expect. So it seems like the water pump is not pumping water. But I replaced this a year ago. And, I do not see any coolant at the weep hole, and no signs of coolant leak anywhere underneath. I put in a as much water as I could before driving it home, and now it is down a bit, but I think it was just getting air out of the system.

So, I'm at a real loss as to how it lost all of its coolant. I'm not letting my son drive it until I figure this out.