Subaru Head Gaskets Can't Seal the Deal

Posted on
Scott McCracken
A close-up of a clean black head gasket above two silver pistons.

There is some debate about the exact reason for this problem, but they're all deeply rooted in one key concept: bad design. Here are some theories:

  • Subaru's single overhead camshaft design (SOHC) engine use the same badly designed cylinder heads from older engines that also had gasket problems.[1]
  • The horizontally opposed engine uses both aluminum blocks and heads, which tend to move around and create more wear.
  • Voltage in the cooling system is believed to contribute to gaskets corroding and failing.[2]
  • Subaru's factory gaskets use a coating that deteriorates faster than a pile of nachos in a fraternity.

Leaking Oil and Coolant

Head gasket failure in a SOHC engine is a passive leak between the coolant jacket, oil gallery and the exterior of the motor.

It typically starts with an external oil leak at the back of the cylinder head. More often that not this happens on driver's side gasket. Most owners only become aware of this when they bring their car in for routine maintenance or if they notice a drop or two of oil on the driveway.

Eventually external coolant leaks can also start to happen. Owners can start using their senses on this one. They might see engine temperature fluctuations, hear noises like engine knocks or smell the terrible fragrance of their engine eating itself alive.

“Oil leaks are bad. Coolant leaks are worse. Mixing the two can be catastrpohic. The gnarly mix will corrode gasket seams and eat away at bearings.”

If these leaks are left untreated, they will strengthen and the cause the engine to overheat ... or worse.

An Unavoidable Issue?

Even following the manufacturer's recommended service intervals will do nothing to prevent this problem from happening. Once your car is north of the 75k mile mark, you're at risk.

I found out today that my Subaru has both leaking head gaskets. Being the ONLY owner of this vehicle and keeping meticulous maintenance and up keep according to the factory manufacturers guidelines, I have to fix both head gaskets at only 77K miles? This is outrageous; I could not have avoided this repair AT ALL. This should definitely be a recall given the amount of complaints on the web about this issue. — 2007 Outback owner

If you really want to avoid this problem, go with a 6-cylinder Subaru engine or use it as an excuse to get a turbo. "But honey, we need the turbo to avoid costly head gasket issues down the road."

Catching it Early

While the problem can't be prevented, you can catch it early and plan for the repairs.

As your car racks up the miles, it might be a good idea to have your mechanic inspect the heads for leaks during otherwise routine maintenance. Any small leak can be monitored over time while you begin to pawn off your prized possessions to save up for the impending repair.

Repairing the Problem

Replacing head gaskets is a very comprehensive and labor-intensive task. The actual gasket itself it usually pretty cheap, but the labor costs are what gets you. Why? Because to truly fix the problem the entire engine needs to be removed and that cost alone will be more than $1000.

That's why when head gaskets get repaired, your mechanic will typically recommend you get other work done at the same time. Things like replacing the water pump, timing belts and tensioners, and thermostats -- all of which is made much easier by the fact that the engine is already removed.

Yes, your bill will skyrocket (most say somewhere between $2200-$2500) but despite the wallet pain, this isn't a scam and will ultimately save you money in the long run.

Head Gasket Problem Review

  • If you own a Subaru with a 4-cylinder, non-turbo engine, your head gaskets will fail at some point.
  • These gaskets have failed consistently for the last 25 years because of bad design or cheap materials.
  • The repair will require the engine to be removed, so it's best to have other work done at the same time.
  • Typical repair costs will be between $2200-$2500.

  1. From "An Explanation of Common Subaru Head Gasket Problems" by Kent Brothers Automotive ↩︎

  2. From "Solving Subaru Sealing Problems" by Tomorrows Technician ↩︎

Generations Where This Problem Has Been Reported

This problem has popped up in the following Subaru generations.

Most years within a generation share the same parts and manufacturing process. You can also expect them to share the same problems. So while it may not be a problem in every year yet, it's worth looking out for.

What Owners Say About This Problem

It's pretty bad when a car blows its head gasket after only 52K miles. Estimated cost to fix is $2100. Reading various blogs / complaint forums etc it seems like an issue that's more prevalent with Subarus than other manufacturers. One person even suggested that it may be due to the horizontal orientation of the cylinders in the boxer engines.

2008 Legacy Owner

I have heard Subarus are bad with the whole head gasket thing. Everyone I know that owns a Subaru has had to have the head gaskets replaced ... Why hasn't Subaru addressed this issue? I bought a Subaru based on reliability and hopes that it would last a long time. I did not expect to have to replace both head gaskets, a leaking rack and pinion, a cooling fan and an oil pan gasket all at the same time at 85,000 miles

2006 Impreza Owner

After our first head gasket blew back in 2006 we were amazed to have the second one blow last night, only two and half years, and 20,000 miles later.

2002 Forester Owner

OK, Now What?

Maybe you've experienced this problem. Maybe you're concerned you will soon. Whatever the reason, here's a handful of things you can do to make sure it gets the attention it deserves.

  1. File Your Complaint is a free site dedicated to uncovering problem trends and informing owners about potential issues with their cars. Major class action law firms use this data when researching cases.

    Add a Complaint
  2. Notify CAS

    The Center for Auto Safety (CAS) is a pro-consumer organization that researches auto safety issues & often compels the US government to do the right thing through lobbying & lawsuits.

    Notify The CAS
  3. Report a Safety Concern

    The National Highway Traffic Safety Administration (NHTSA) is the US agency with the authority to conduct vehicle defect investigations & force recalls. Their focus is on safety-related issues.

    Report to NHTSA