I'm slighlty confused. The cooling system is closed. The coolant is used to absorb heat from the engine and transfer it to the air via the radiator. If the system is closed it circulates via the waterpump. If the head gasket is breeched and only coolant is going out then is the pressure coming from a breech between the engine block and the coolant?

Where is the pressure being generated? Apart from heat expanding the coolant.

thanks

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1991 190E 311K [Brilliant Silver/Black MBTEx] -retired
1996 E300 315K [Black/Grey MBTex]

Want to put a tank in the trunk for WVO/SVO in the E300 Need to find a place to store my OIL!
Still procrastinating about the biodiesel/WVO
Made some biodiesel but so afraid to pour it all in - I've added some and think I'll supplement my fuel to see how I make out

Made some biodiesel but the process scares me - methanol fumes are not your friend! Need to do this outside.