i've had a similar problem develop, but i havn't had the radiator get that bad on me yet. it started when it was cold as $hit and my car sat for 2 days. i started it up and there was a leak from the top of the rad. where the teeth hold the top in like you said. as time went on it was worse as i sat at idle than when i was running. it also seemed that the therm. stopped working b/c my coolant fan wouldn't turn on, but there was no issue with overheating at all. i just tried to keep coolant in the overflow which kept coming out, but now since it has warmed up the problem has seemed to go away. :thinking: no idea what happened, but sounds similar. hope i don't develope problems like yours. keep me posted on the solution to your situation...

 

sounds like you've got the same problem developing; leaking from the radiator teeth, constant refilling of the coolant resevoir.

have your mechanic take off the radiator cap, stick that inspection probe at the opening and cover. if there's a reading in the hydrocarbons, you've got a blown head gasket.

let's hope it hasn't reached that point yet.

at this point the engine additive has stopped the problem.

 

Often times a second set of eyes is best used in detecting overlooked things. I'd rather not assume anything simple has been taken care of.