Thanks guys for all of the ideas, I have a bad feeling that ASEmaster hit the nail on the head. I have had a misfire at start up 3 times in the last month (always cyl #6 which is closest to the EGR valve). I assumed I had a bad plug wire (even though they were only about 4 years old and 30,000 miles) as it always seemed to happen on humid mornings, and would go away after about 30 seconds of running… I did a full tune up on it last weekend and have not had a misfire since, no codes no nothing. Also a bad intake would explain the lack of leaks, and complete lack of evidence of a bad head gasket…
Let me ask you this, can I assume that if I remove the air intake, and open the butterfly on the throttle and shine the UV light in I should see the dye in the intake right??
I am leaning away from the rad cap only because I am not getting any dye around the rad cap at all, and even if it was venting coolant every now and again I should see dye residue around it.
Thanks again guys