While cleaning and running Seafoam thru the intake, and changing oil+filter today, I noticed a little coolant seepage on the right head. It's not even wet, just crusty green crystals.

If this is the infamous 2.5 Head Gasket problem, I guess I'll find out Monday, as I have an appointment with the stealer to put in the coolant conditioner.

The overflow tank does have a scummy, thin layer of oil in it.

My question is-how serious is an external coolant seep? Other than the slight mess and having to top up the radiator somewhat more frequently, what harm can it do?

Treeman

water it will overheat. It did not really bother my car as long as I kept coolant in it. It bothered me though and I had the gaskets changed beofre Subaru came out with the goop. Let us know how the goop works on your leak. Now I have both gaskets and goop so I hope I'm covered.