A few months back when the weather warmed up, I took the opportunity to get rid of the green coolant in my 300SE that the PO left me with. I went out and got two gallons of MB antifreeze, and flushed out the system completely. I then refilled it with distilled water and MB antifreeze mix.

Everything seemed fine for a while. A few days later, I checked the coolant level and found it low. No big deal, I thought. There must have been an air pocket in there........

My dad then borrowed the car for a couple weeks while I worked on the 560, and when he brought it back it had just started overheating, which he hadn't noticed until I pointed it out

So, I wound up putting about a gallon of coolant into it. I then discovered that the hose fitting at the top of the thermostat housing was loose and weeping a bit. So, I cleaned up the connection and re-tightened the hose and thought I had fixed the problem.

This weekend I discovered it low again, by about a gallon!

I can't find any place where it appears to be leaking.... All hoses seem tight, the radiator is less than 3 years old and is genuine MB.

The thing NEVER leaked a drop when it was running the green coolant. Now all of a sudden, it is mysteriously losing about 1/2 gallon per tank of gas.

Where could it possibly be going? No sign of coolant in oil, no signs of leaks!


Ideas?

__________________
-tp


1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition