New member here with question. My son, with Impreza 2.5 just replaced his head gaskets w/felpro mls, etc. He only had a very, very minor coolant leak prior to replacing the gaskets. No overheating, no oil in coolant, no misfiring, and excellent compression in all four cylinders, etc. He decided to replace the gaskets so that he would not have any future problems. He reassembled and now has an overheating problem, but only after putting the transmission into gear. It will sit and idle for any length of time, even with fairly high rpm's, with no issues, but as soon as he engages the tranny, it begins to heat up. He was and is very meticulous in teardown and reassembly. Has checked, rechecked all fluids, lines, and everything else he can think of. Any help would be appreciated. I can only provide moral support, as I am a small-block chevy guy. Thanks.
PRB