Bought a used 98 Subaru Legacy Outback. Ran a little rough but a quick inspection found a broken exhaust pipe up near the manifold and 2 of the 4 spark plugs were broken. After addressing those things, it was a lot better, but still kind of rough. Good power though. As winter came on I noticed the heater wasn’t warm. The engine temp gauge was working fine but just for giggles I checked the coolant level anyway. Cut to the end–there was a hole in the lower radiator hose and so no coolant at all.
Replace hose, add coolant, system won’t burp. In fact the coolant in the res is looking frothy and boily despite not being all that warm. OK, head gasket. No biggie. This is a boxer engine and I’m just going to pull it to work on it, maybe do the clutch plate, timing belt, etc. while I’m in there. Big job, but fun for me and the kids. So, after all that, here’s the question:
Aluminum heads: shop assures me if the car is running well it is unlikely for an aluminum head to be warped so badly it can’t be fixed by planning it. But what about the aluminum block? What are the odds I’ve got a hosed block as well? It’d be a pity to get my heads spruced up and replace a bunch of stuff only to find out I’ve still got a paperweight.
Clearly, it’s a Schrodinger’s Engine situation, where I can only really know when I get in there. I’m just looking for the odds.
it would really depend on how hot the engine got. IIRC the Legacy has an open-deck engine block, so it has a rather higher risk of the cylinders going out of true after a severe overheat. only way to be sure is to have an engine shop inspect the block and heads for variance. and I would recommend that, otherwise you’re likely to be replacing head gaskets fairly often.