Hello all, I have a 99 f 250 with 200K miles on it and it is starting to get fuel into the cooling system, no other problems or symptoms, I noticed it a few weeks back, it was only a few ounces at first but I am starting to see more. I have drained the system and replaced the coolant. Any ideas?

I can't say I have heard of this before, I would only offer a guess that its either a head gasket or someone playing a trick on you... are you losing any antifreeze?

Leave the radiator cap loose, go for a 20 minute drive, put the cap on, the engine is fully warmed so the cooling system should not pressurize not, go for another short drive, if the radiator hose gets hard (pressurized), I would lean towards a blown head gasket.

I wonder if there is coolant flowing in the intake manifold, I don't think a bad intake gasket would cause this??