An explanation of common Subaru head gasket problems

Chances are, if you own a Subaru, you’ve already caught wind of the cylinder head gasket failures that are dogging many of the Models that are on the road today.  What started as a nasty rumor, has more recently become a ground swell that sounds more like an angry mob with pitchforks.  Subarus are currently experiencing and alarming rate of head gasket failure.  We won’t deny that.  This article is intended to inform our audience on the who, what, where and hows of the problem.

Beginning in the 1996 model year Subaru released a 2.5 liter engine that boasted two overhead camshafts per cylinder bank.  This engine appears in virtually(exceptions apply) all 1996-1999 Outbacks, 1996-1999 Legacy GTs, 1998 Foresters, and the pre 2000 Impreza RS. The head gasket in this engine will fail such that combustion gas and coolant mix.  The evidence of this will appear in the coolant overflow tank as an oily, stinky residue.  If ignored the leak will develop into a classic “blown” head gasket complete with overheating, white smoke and even cracking in the block and head.

In 1999 Subaru began to phase out the dual overhead cam engine and replaced it with a single overhead camshaft engine that used a completely new intake, and cylinder heads.  The block and internals are a redesign, but the family genes from the previous 2.5 liter are clearly present.  This engine is still available in some current Subaru models, and powered all but the turbo, six cylinder, and 2.2L cars for over a decade starting in 2000. This engine wasn’t supposed to have head gasket issues, but sadly the gaskets have failed at an even greater rate than the previous engine.

These motors are commonly referred to as the Single Overhead Camshaft or SOHC engine.   The head gasket failure in the SOHC motor is best described as a passive leak between the coolant jacket, oil gallery and the exterior of the motor. In an engine that is leaking, this means that antifreeze,  and engine oi,l will start to appear on the gasket seam between the cylinder block and head.  Early indicators of an external head gasket leak are an oil burning smell or a single drop of coolant in the garage.  As the leak develops enough coolant will escape so that engine overheating is likely.  We are seeing this kind of failure with cars as new as 2006 and mileages of under 90K.

If you find yourself feeling like your Subaru glass is half empty here are a couple of bright spots.  We have replaced a lot of these head gaskets, and when the job is done right(our way) you can enjoy many more miles of dry, leak free, head gaskets.  Also, because the head gasket job is very comprehensive and can include work like the timing belt, water pump, valve cover gaskets, tune-up, and clutch we encourage our customers to “bundle” these repairs and in doing so save a considerable amount on labor.   Don’t let a mechanic replace your head gaskets and neglect to check how much life is left in your clutch. It’s the classic “while we’re in there” job.  We are always glad to discuss your options and provide a written quote outlining our approach.  Swing by or give us a call.

 

 

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