This problem seems pretty odd to me. 1986 Dodge D100 truck, manual transmission (OD), with high milage continually fills the overflow bottle with coolant.

This thing starts EVERY time I hit the key. Runs so good there can't be anything seriously wrong with it. (OK, once you get past the blue fog on startup, but I'll get those valve stems seals in there someday..) It doesn't run hot, but every time I look, the radiator is down there and the coolant bottle is full! I recycle it to the radiator and away I go again for a month.

I originally thought it was blow-by (rings), but then I thought how would that put positive pressure in the coolant? Blow-by would show on the breather, but not this one.

I'm thinking head gasket cross-over into the coolant. If it's not that, cracked head maybe? It's been hot once or twice...

What else could it be?

JK mity225@mchsi.com