So this morning the check engine light came on so I drove it to advance about 10min to check to see what to code was and it came back p1151 and the overtemp problem light came on. I ended up adding about 1.5l of water to the radiator and drove for about 20 min and no overheating. Any ideas as to what could be going on. The car had about 325k I think. Edit. I changed out the inverter water pump about a year ago.
