I'm looking for the cause of my loss of coolant. I'm losing about a gallon of coolant every 4-5 days and none of it is in the engine bay or on the ground. I'm not overheating, or driving roughly, no coolant in the oil drained while cold. The previous kerosene flush/oil change was due to a gunky chocolate milkshake colored muck in the cam covers, but I haven't seen a sign it again since. I also started experiencing random and varying losses of oil after changing my catalytic converters about two years ago. What's the best method to use to check our trucks for a head gasket leaks? Can I remove the fuel pump and starter fuses and crank the car with one plug in each cylinder at a time to see if it spits coolant at the reservoir? I've seen several videos on testing for blown head gasket and they tested at the radiator cap several ways for compression gases, can I do all of these tests just at the reservoir? Could there be another cause for the loss of coolant? Is this a good candidate for BARS professional head gasket repair fluid?