Jassz,

Have you thought of replacing your coolant with Evans waterless coolant? The only disadvantage is the cost, about $25 per gallon.
It is used full strength, so you need twice a much as regular AF that is mixed with water.

It is not ethylene glycol. Its ethylene polypropylene and boils at 375F, yes three seven five Farenheit and with out a pressure cap. Therefore it takes the strain of pressure off the entire cooling system. Freezing is something like -40F.

Here is another cheap out by the Manufacturers: instead of building a more expensive non pressurized cooling system that will cool the engine properly, they make a cheaper pressurized system that gives owners problems after the warranty either runs out or are not covered by the warranty.

I put the Evans coolant in 2 of my MB: 300SD and 300SD. In a trip to the west US last year, I admit the engine ran a little hotter up the hills in the Rocky Mtns but as soon as I went over the top and down the other side, the temp came back to normal. And all this with the radiator cap loose so there was no strain on the radiator, water pump, hoses, heater core, ETC. I also use it in my Diesel tractor. It always overheates because of chaff preventing air from going thru the radiator. With regular antifreeze, it was boiling and loosing coolant by the time the over temperature light came on. With the Evans coolant the light comes on long before it boils and I can stop and remove the chaff with out any boiling or loss of coolant. Again without pressure on the system.

I think Evans is great amd well worth the extra cost.

P E H