I have recently just got a f250 with the 5.4L, and think there is a possible head problem. I have been driving here and there and noticed that the antifreeze level has gotten lower and lower to finally it was below minimum before starting the motor, also smelled burning anti freeze after driving a few times. Have not seen any leaks around the truck, so jumping to the conclusion of the head gasket is bad. When I bought the truck the guy thought there was a head problem, but was not sure. One of the coils were bad so it was replaced, the spark plugs are also like new. Not sure what to do, do I replace both gaskets or just the side that is bad?

 

Simple diagnosis would be to start the truck and go back to the tailpipe to smell for a 'sweet' smell. It's pretty easy to differentiate from regular exhaust smell. Since the coolant is a closed system, loss either appears on the ground or in the atmosphere (aka tailpipe). If you're going to replace a head gasket, it's best to replace both at the same time...good insurance because if the one failed, you just don't know the condition of the other. Are there a lot of miles on the motor? The reason I ask is that if you go through all the time/expense of replacing head gaskets, you're still going to have a motor with (perhaps) lots of miles. I had it happen to my 96/460 and just went for a remanufactured motor instead. Same result, just a tad more money, and brand new motor afterwards. Just a thought...and sorry to hear that you likely have a blown head gasket...never a good thing. Good luck!