Hello,
Octavia 2 2008 2.0TDi 125kW CR CEGA
The car was pressurizing the water, so I had the head gasket replaced, the head was straightened and pressurized, the exhaust gas cooler was changed, the timing belt kit with water pump (plastic propeller).
The car drove ok for about 2000km until driving on the highway when the water started to boil, I replaced the thermostat (5 pcs in total) and since then it won't open to the large cooling circuit, the upper radiator hose is warm, but the lower one is icy, only after turning off the engine does it start to heat up from the thermostat. If I take out the thermostat and put a cardboard in front of the radiator, everything is completely fine. Yesterday I disconnected the radiator, flushed it, it is passable, I removed the distribution pipes and put a Continental water pump with a larger metal propeller. Still the same, the car boils water in a small circuit and after the water overheats it stops heating, the water boils into the expansion tank..