Well folks, a while back I posted here about the problem with my wife's Forester breaking on the Interstate down due to overheating. Thank you for all the feed-back. I went out on the next warmer day (a balmy 15 degrees outside) and replaced the thermostat, which I thought was stuck. Turns out now that when the engine warms up, back pressure is introduced into the cooling system. A repair shop I trust checked it out and told me its either a blown head gasket or a cracked cylinder. So I'm looking into getting the head gaskets replaced (at least a $1200 job - yikes) and I've thought about trying to find a low mileage used engine or a rebuild (the only remanufactured engine I've located so far was a long block at $4600 plus without installation). Its a 2.5 liter (non-turbo) Forester in otherwise good condition with about 100K miles on it. I thought I'd consult you gurus to see if anyone else has had similar problems and to see what you think. There is no guarantee that it is only the head gaskets and the engine did overheat, so I'm worried about oil rings being bad, etc, after I spend quite a lot on the head gaskets. What to do .. what to do. Thanks.
John