Truck repaired.
What was the cause of this issue?
Often it is the Injector sleeves. But do check it isn’t driver error missusing a watering can and putting fuel in it.There are plenty of youtube videos on various makes of engine showing fuel in the coolant. Also plenty of advice earlier in this thread.
I have coolant in fuel, not fuel in coolant.
Ive drained the fuel tank and fuel filter and separator, and coolant returns to tank overnight.
Although the pressure can randomly increase in coolant circuit after a long day of driving- is that still affected by the injector sleeves? Truck is FH480