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My Subaru Legacy wagon (96) overheated yesterday, and I noted that there was antifreeze sprayed across the top of the battery and right around the reservoir. I had it towed to the nearest shop, b/c my mechanic was too far away. The shop initially told me that my water pump needed to be replaced, as well as the timing belt and thermostat. Today, they called and said that now they had to replace my head gasket, as well, b/c the antifreeze was mixing w/ the oil. I’m already at $850, and they wouldn’t give me a range b/c nothing is open today. Can someone tell me if this sounds reasonable? I’ve never brought my car anywhere except my usual shop, and I haven’t had anything major go wrong on the car in the year I’ve had it, so I’m not sure what to make of it.

It’s near impossible for a shop to know the extent of damage on things like this but they should have made you aware of potential engine problems based on an overheating complaint. Subarus are all-aluminum construction and do not take overheating well. When the engine gets hot then one MUST pull over right then and there; not continue to drive it.

Your engine has 2 head gaskets and both should be replaced even if one has given up.
The problem you have with replacing head gaskets only is that the oil is now diluted with coolant. Coolant is not a lubricant and diluted engine oil will damage other engine internals; crankshaft bearings, cam lobes, etc, etc. In a nutshell, this could mean a complete engine overhaul or replacement.

The shop should have also verified the condition of the oil before doing anything at all. Point being is that if you replace the head gaskets/rebuild the heads, etc. you may be left with an engine that has low oil pressure and rattles or knocks and you’re right back to needing a complete engine.

Half the Subaru threads on this board involve blown head gaskets. If nothing was leaking coolant and your car overheated, there’s a good chance a failed head gasket is the cause…But we cant look at your car so we are just guessing too…

Thanks so much for your response, even though potentially needing a whole new engine is never what one hopes to hear…

Is there a way they can tell if the whole engine needs to be replaced now? The car probably isn’t worth a whole new engine. I’d rather not learn that after shelling out the cost of fixing the water pump.

Thanks in advance for your response!

Does your Subaru have a 2.5L engine or the 2.2L? The 2.5L(non turbo) is a ticking time bomb for head gaskets otherwise it is not common at all to have a failure. I would make sure the diagnosis is definite.

It’s going to be real iffy as to determining whether the lower end is damaged. It does not take very many minutes of running with coolant diluted engine oil to cause excessive wear on the rod/main bearings, etc.

Another problem that could surface is piston ring/oil consumption problems. Overheating can cause the rings to seize in the ring lands (grooves) and since they’re unable to expand and contract the engine may burn oil after the head gasket repair.
A compression or leakdown test could detect this but with blown head gaskets the test could not be performed much like an oil pressure test would be irrelvant right now.

On a “normal engine” one could simply drop the oil pan, remove a few bearing caps, and easily replace the bearings if bad. Due to the Subaru Boxer engine design this is not possible. The only way to do this would be to remove the engine and completely disassemble it; which means a complete rebuild.

This is a coin flip call. One could replace the head gaskets (and the heads should be reworked at the same time by an auto machine shop) and hope for the best or find another good used engine to install.
Wished I could be of more assistance and the only thing I can add is that a shop should consider these potential problems and notify you, the owner, in advance before performing any repairs at all.