Non turbo 4 cylinder applications all have head gasket issues, you've heard this before, most of you know this, and yes its a result of a bad/faulty design with the gasket.
The factory gaskets have a coating that deteriorates over time (typically between 80-120k miles. That range is dependent on if you've run the SOA mandatory coolant conditioner, which is designed to get you past that 100k mile hump).
The symptom of leaking "head gaskets" is oil weeping between the head/block surfaces. This weep over time turns into a significant leak, which then turns into coolant leaking as well, after that symptom you often times will go into overheating, from there its a few mile slippery slope...which then has coolant and oil intermingling together.
If you haven't guessed it yet, this is where bearings get trashed, you develop a rod knock and hopefully at this point you've realized its about to be over but recognize before the next critical stage.
The sad thing is....it doesn't need to get to this point. If you work with a specialty shop its easy to point out early on when this is happening (at the weeping stage) and proactively fixing it. By doing so, you 1- secure your investment with your vehicle, 2- save yourself the headache of being broken down on the side of the road, and 3- you get to enjoy your car for another X amount of miles b/c you didn't let it catastrophically fail.
Did you know when we do head gasket jobs here at LIC Motorsports we don't install the same gaskets that do the same thing? Would you be shocked to know that the dealer and most other independents still install these bad/faulty gaskets to this day when they perform this job (reason being is Subaru hasn't revised the gasket on the older SOHC vehicles).
These vehicles all have cylinder head gasket related issues:
You can purchase revised/upgraded gaskets here: Non Turbo Upgraded MLS Head Gaskets
More info about our Head Gasket Service here: Maintenance Service Page
Here is images of when someone has let it go to far and more or less driven there car into the "ground" (that slurry leaking out is the "milkshake" of coolant/oil that has mixed).
Most Articles are written by Noah Levy.