Subaru Head Gasket Troubles (Years & Models Reported)

Subaru vehicles have been known for being reliable and efficient. That is why Subaru continues to be loved by its loyal customers. Subaru's stellar reputation has not been without its faults. Some 2.5-liter four-cylinder engines are notorious for blowing head gaskets that can lead to expensive repairs. Which models have head gasket issues with Subaru? What should you do?

It is important to understand which Subaru models are best avoided if you're looking for a Subaru on the used market. It’s also imperative that you understand what a blown head gasket is so you can avoid any car with symptoms. 

What's a Head Gasket?

You will find the head gasket on your engine. It’s a thin strip of metal that contains holes, resembling a piece of Swiss cheese. The head gasket must be placed between the engine block & the cylinder heads when the motor has been assembled. 

It is important to keep the proper tolerances between heavy metal parts and the head gasket. The gasket keeps the coolant flow and oil passages separate. 

It is important to place the headgasket correctly and secure it properly. Most engines' head gaskets will be good for the life of your vehicle. It would only need to be replaced if major engine repairs were being done. 

But a bad head gasket may cause serious problems. When the engine heats up or cools down, the gasket will move slightly. To ensure seals are working properly, each operation cycle requires that the head gasket absorbs and dissipates heat correctly. A faulty head gasket can cause oil and coolant to start mixing, leading to expensive situations. 

How do Subaru Head Gasket Issues Affect Your Models?

Although any engine can experience a failure of the head gasket, some Subaru models are known to be more susceptible. Head gasket problems are due to the engine design. 

It is most vulnerable to the Subaru EJ25 motor. There were many options for these 2.5-liter engines, which have been updated a number of times. But, problems arose when the composite gaskets failed. 

The following Subaru models are most affected by head gasket issues:

• 1999-2010 Forester 
• 1999-2011 Impreza 
• Outback, 2000-2009 
• 2000-2009 Legacy 
• Baja 2003-2005 

The design of the boxer motor could also be responsible. A Subaru boxer motor is flat and does not stand up as most other engines. These engines have pistons that move side-to-side. The engines have amazing weight and balance. However, the fluids build up near the head gasket rather than draining properly after it is shut off. The seal can be damaged even after parts have been upgraded. 

Blown Subaru Head Gasket Signs

1. Heating Engine

A head gasket can fail when the engine heats up. This can also lead to other problems. When the head gasket isn’t sealed as it should be, hot gases from the exhaust end up in the cooling system, or the coolant can leak into the cylinders. Overheating engines can result in either a leaking coolant or hot exhaust gases.

The cylinder heads may warp if you drive while your engine heats up. You may also experience damage to your catalytic converter from steam, which can lead to a much larger repair bill. 

RELATED : 5 Signs You Have a Blown Head Gasket

2. Power Loss 

Leakage of the engine block could cause poor performance. The engine will compress less if the fuel or compressed air can escape.

A lack of compression creates an engine that runs rough and doesn’t respond. You might also hear sounds that could be indicative of an exhaust leak. 

3. Oil Contamination

When the head gasket blows, it’s common to see a milky sludge on the dipstick or under the oil filler cap. It is caused when coolant mixes with oil and has been called a "milkshake".

Coolant can get into oil and cause damage to the engine's bearings. The head gasket will have to be changed, and the engine will also need to be flushed with new filters. The bottom end should be disassembled in order to inspect the bearings. 

4. White Smoke

If white smoke starts pouring out of the exhaust, it’s a tell-tale sign of a blown head gasket. Because of antifreeze leaked into the cylinders through the head gasket, this smoke is likely to be sweet. 

The coolant becomes steam as part of the combustion process. If the oil passage is leaking, however, it might cause smoke to turn blue, though this is less common. 

5. External Leaks

You will see either oil or coolant leaking if the gasket between the water or oil passages fails. While this condition is still serious, it’s the least worrisome way for a head gasket to blow.

You will initially notice a drop in fluid levels and may also see the leak. However, if the fluids get too low, you could create other engine issues, so don’t ignore the problem. You should be cautious with leaking fluids as they can ignite your car. 

Subaru Head Gasket Replacment Cost

Replacement costs of Subaru head gaskets range from $2,000 to $4,000. It is possible to spend anywhere from $1,200 up to $3,000 on labor. A typical parts bill can be anywhere from $800 to $1500. This is especially true if you include the idlers, tensioners and timing belts. A manual transmission Subarus can cost up to $500 more. 

The average DIY mechanic will not be able to repair a headgasket. Your Subaru will need to stay in the shop at least for a couple of days. An engine specialist should be able to work on it because the motor must be removed to make sure everything is working properly.