Hello! I have a bmw 520.i 24V E34 and I think(not sure) I have problem with headgasket. I changed water pump, thermostat, cleaned the raditor, change coolant but engine overheats(sometimes). The temperature gauge will get into the middle, and stay there for few minutes and then move to the red zone but never touch it. I don't have visible warings such as:
-Coolant in oil or viceversa
-Mysterious loss of coolants without traces
-Thick white smoke coming out of the tail pipe
So, what can be?