Disappearing coolant...
 

Ever since day one, my MY02 ML320 seems losing coolant about 1/3-1/2 inch below the coolant reservoir cool level line every 7k-10k miles. Dealer just did a pressure test and didn't find any leaks.

Is this normal for this engine? This is the first car I've own having this wired habit; a bit worried about the gasket now. Truck has only 20k miles.

Re: Disappearing coolant...
 

Not normal. My 2000 ML never required topping off for three years, then it was flushed and replaced per normal maintenance schedule. You've got a leak somewhere.

Recommend that the truck is parked at the dealership over-night with EXPRESS instructions to NOT start it the next morning, but instead the pressure tester is put on the truck with the truck sitting OUTSIDE and then inspected for leaks COLD.
Probably a loose hose clamp.

Gilly

Cardboard works well
 

Also you can put a big piece of cardboard under your engine over night, you can pinpoint where the leak is coming from.. usually you can trace it back! to see if its a loose clamp or not..