my 97 outback was diagnosed with a head gasket leak (coolant in overflow, moisture in exhaust, milky substance in oil ect...) on the EJ25 DOHC. Car has body damage and 150k miles so decided not to fix, rather drive into the ground (i commute ~1 mile to work each way).
Question is this, what is the likely catastrophic failure mode for leaking head gasket and is there anything i could do to prolong the engine before inevitable catastrophic failure?
thanks, mark
One other on this or another Suby news group used a "block sealer" to prolone the enevatable. He said he got it at AdvancedAuto parts. I have no idea if it works but for $10 it may be worth a try if the gaskets are not to far gone. ed
I would expect it to die a gradual death. Frequent oil changes with cheap oil (even if you keep the filter the normal interval) should minimize the destruction from that end. My guess is the engine will gradually get crankier and the temperature will get more unstable as the hot combustion gasses eat a larger path past the gasket - a light foot will slow that, also.
Mike
I'd be cautious using some non-Subaru approved stop leaks. Subie radiators have very small passages in the radiator. Typ OTC products are likely going to plug your radiator. BTDT
Mine finally got plugged while on a trip and local radiator shop had never worked on a Subie before. I did most of the work they were able to remove the top tank and found the radiator almost completely plugged. Shop commented on how small the passages were. Had to do some looking to find a rod small enough to fit into the passages. Fortunately all turned out OK.
Mickey
so i tried the sodium silcate (liquid glass) block sealer treatment. I think it stopped the leak, the engine idled at high temp for ~15 mins, then went back down to normal temp. hopefully that sealed whatever leak was present. afterwards, ran the engine at ~2-3000 rpms for a few minutes and no overheating.
flushed the cooling system very aggresivley before and after, and it appears okay for now. i'll give it 3 days and flush and fill again to be on the safe side.
all, thanks for your input!
Hi Mark,
I posted instructions before on this forum. I used the "blown head gasket" liquid (not sure if it was "sodium silicate" - it looks like cupper dust). Actual repair process takes over than 24 hours and includes 3-4 cycles of heating engine and waiting to cool it down. It repairs certain leaks. I had exaust gas in the coolant (I think most of a Subarus who have this problem have this particular leak). I bought "radiator flush/drain" valve and I flushed the cooling system throughly before and after. I got about 20K after "repair" and sold it. As far as I know it runs great for now.
Good luck,
Mike
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