I've had this perpetual issue of coolant loss for the past couple of months in my 87 fj60. All indications are telling me I have a cracked head with no visible leaks and definite milk shake residue in the engine. I've brought it to to a pretty knowelagable cruiser mechanic who has told me he's pretty sure it's not the head. How he came to that conclusion I'm not sure. What we have done is replace the lower radiator hose, engine oil cooler seal and replaced the thermostat. The problem has gotten a bit better, at least the truck is not overheating any longer and the coolant loss is not as great. On average I would burn through the reserve coolant tank on a 30 mile commute at freeway speeds. Now I'm down to about a quarter to half of the reserve coolant on a 30 mile drive. The mechanic had mentioned installing an oil cooler seperator, but that seems like applying a bandaid to a much larger problem. Being that I am a weekend warrior mechanic, has anyone run into this issue and the outcome was not a cracked head?