The Three Common Subaru EZ36 3.6 Engine Issues. The Subaru EZ36 is a 3.6L flat-6 engine that first appeared in 2007. Its DOHC 24 valve engine produces 256 horsepower and 247 pound-feet of torque. Subaru 3.6 engines are well known for their use in the Legacy and Outback models from 2010 to 2019. The EZ36D boxer engine has a lot to offer in general, but no engine is perfect. This guide covers Subaru EZ36 3.6L engine problems, as well as specs, reliability, and other topics.
What Vehicles Make Use of the Subaru 3.6 Flat-6?
The following models use EZ36D engines:
- Subaru Tribeca 2008-2014
- From 2010 to 2019, Subaru Legacy
- Subaru Outback 2010-2019
Engine Specifications for the Subaru EZ36
The following are some specifications for the 3.6L flat-6 engine:
Aside from its unusual flat-6 engine design, the EZ36 specifications are fairly standard. The displacement is slightly more than 3.6 liters, and the engine is naturally aspirated (NA). Weight is reduced by using an aluminum head and block design. The EZ36 engine’s DOHC, 24 valve design contributes to increased power and torque.
It’s slightly oversquare, with a bore 1mm wider than the stroke length. 10.5:1 compression is quite high, but it is typical for a NA engine. All of these specifications allow the Subaru EZ36 engine to produce 256 horsepower and 247 lb-ft of torque. Nothing spectacular, but it’s more than enough power for most people.
Common EZ36 Engine Issues
Among the most common issues with the Subaru EZ36 3.6L flat-6 engine are:
- Oil spills
- Tensioner for belts
- Tensioner for the timing chain
Throughout this article, we’ll go over these Subaru EZ36 3.6 flat-6 issues. Before we get into these issues, it’s important to make a few notes. For good reason, we’ve categorized these issues as among the most common. It does not always imply that failures are common in the true sense of the term. Rather, when problems arise, these are some of the most common areas in which they manifest.
Nonetheless, the EZ36 engine provides excellent overall dependability. It’s a significant improvement over Subaru’s original EZ30 engines. Anyway, we’ll return to the topic of dependability at the end of the article. For the time being, let’s jump right in and talk about the three most common Subaru EZ36 engine problems.
1) Leaks in the Subaru EZ36 Engine Oil
There are numerous potential locations for oil leaks to develop in the Subaru EZ engines. It makes extensive use of seals and gaskets, which leaves plenty of room for leaks. Oil leaks are common in all engines as they age and mileage increases. This rule also applies to the EZ36 flat-6 boxer engine. As a result, oil leaks on older Subaru 3.6L engines are common.
Gaskets and seals deteriorate with age. They become brittle, crack, and oil begins to leak. These leaks usually start slowly, but if not repaired promptly, they can grow into large leaks. The front timing chain cover on the EZ36 engine is massive. The oil pan gasket on the engine is also made of two pieces. The point is that there are numerous large areas where oil can leak from the 3.6L boxer engine.
Most oil leaks will appear after 8 years and 100,000 miles. Leaks can and do occur earlier, but it is usually due to age and mileage. The timing chain cover, valve cover, oil pan gaskets, and crank seals are all common locations for EZ36 oil leaks.
Symptoms of an EZ36 3.6L Oil Leak
Oil leak symptoms are usually obvious and straightforward. Nonetheless, keep an eye out for the following signs that your Subaru EZ36 3.6L engine is leaking oil:
- Visible dripping
- The odor of burning oil
- Engine compartment smoke
- Engine oil is low.
The most common symptom and a dead giveaway that the EZ36 is leaking oil is visible oil leaks. Many leaks, however, start small and may not drip onto the ground for some time. As a result, without a visual inspection, some oil leaks may go undetected. Furthermore, some oil leaks drip onto hot components and burn away. Burning oil odors or light smoke from the engine compartment could indicate a leak.
Otherwise, low engine oil is a possible symptom, but it is unlikely. You’re more likely to notice a visible leak and drops on the ground before your oil runs low due to an oil leak. Engines consume some oil naturally, so a low oil level does not always indicate a leak.
Subaru Oil Leak Repair
Oil leak repairs on the EZ36 boxer engine can vary greatly depending on the type of leak. However, most oil leaks are caused by inexpensive $10-50 gaskets and seals. This makes Subaru 3.6 flat-6 oil leaks a low-cost DIY project.
The real killer of oil leaks can be labor costs. Many Subaru EZ oil leaks can be repaired in a few hours, so budget between $200 and $400. However, some of the more complex oil leaks can result in higher repair costs at a shop.
2) Serpentine Belt Tensioner EZ36D Flat-6
Some EJ series engines have two belts, but the EZ36D engine has a different design. All of the accessories are controlled by a single serpentine belt on this engine. The single serpentine belt is then tensioned by a single belt tensioner. The spring-loaded EZ36 serpentine belt tensioners apply the proper amount of tensioner.
The tensioner’s spring wears out over time, which can lead to a variety of problems. For one thing, the spring may wear down and no longer apply enough pressure to maintain proper belt tension. Another issue is that the EZ36 belt tensioner spring may “bounce” around while the engine is running. Then there’s the pulley bearing, which can seize and cause problems.
The point is that the Subaru EZ36 serpentine belt tensioner can fail in a variety of ways. Many problems are age-related, as the tensioner/pulley simply wears out with time and mileage. Belts and pulleys are standard maintenance on many vehicles, so it’s not a big deal in the grand scheme of things.
Symptoms of the Subaru EZ36 Belt Tensioner
The following are some symptoms of belt tensioner problems on the EZ36D flat-6 3.6L engine:
- Strange sounds from the belt
- Failures of accessories
- There is no start.
There aren’t always obvious symptoms before a serpentine belt fails. Engine squeaking or grinding noises may indicate a problem with the EZ36 belt or tensioner. Otherwise, most other symptoms appear after the belt has failed. If you’re having problems with your A/C or other belt-driven accessories, it’s time to inspect the belt and tensioner.
Because water pumps are driven by a belt, improper operation can result in overheating. A total belt failure will almost certainly render the EZ36 3.6 engine undriveable. The alternator is powered by a belt, which would result in a no-start situation.
Serpentine Belt EZ36D 3.6 Replacement
Replacing the belt tensioner on the EZ36 is a simple task. It’s usually a good idea to replace the tensioner and belt at the same time, especially on high-mileage Outback and Legacy models. The serpentine belt and tensioner kit will cost between $100 and $150 in parts. With another $150-250 in labor, the job will cost between $250 and $400.
3) Timing Chain Tensioner Issues on a Subaru EZ36 3.6L
The timing chain tensioner is the final component to check for EZ36 flat-6 engine problems. Fortunately, Subaru timing chains are dependable and rarely fail. The timing chain tensioner, on the other hand, is a different story. This is also the least common issue we’re talking about for the Subaru EZ36 engine.
The timing chain tensioner, like the serpentine belt tensioner, is in charge of maintaining tension. Simply use the timing chain instead of the accessory belt. Anyway, this plastic tensioner tends to deteriorate with age and mileage. It eventually loses the ability to maintain proper tension on the Subaru 3.6L flat-6 timing chain.
When compared to the EZ30 engine, timing chain tensioner problems are less common on the EZ36D. However, problems can and do arise. It is critical to look for symptoms. The sooner the tensioner is caught, the less likely it is that the timing chain or other parts will need to be replaced.
Timing Chain Tensioner EZ36D Symptoms
Look for the following symptoms of Subaru EZ36 timing chain tensioner issues:
- Rattling noises
- Slack in the timing chain/marks
- Engine light on
- Engine performance is subpar.
Listen for rattling sounds, as this is frequently the only symptom preceding timing chain tensioner failure. Some slack develops in the timing chain as the tensioner wears down. This causes the rattling sounds and marks on the timing chain. However, visual inspection can be difficult.
If the tensioner fails sufficiently, the belt may slip or jump a few teeth. In this case, the EZ36 will display a check engine light and perform poorly overall.
Tensioner Replacement for Subaru Outback
Again, problems with the Subaru EZ36 timing chain are uncommon. However, if the tensioner fails, timing chain replacement may be required. Timing chain kits can cost between $200 and $400 in parts. Labor can also be quite involved, so an additional $300+ for labor is standard.
When all is said and done, it results in a fairly costly repair. Fortunately, timing chain tensioner issues on the Subaru Outback or Legacy 3.6 flat-6 engine are uncommon.
Reliability of the EZ36 3.6 Flat-6
Is the Subaru EZ36 flat-6 engine trustworthy? Yes, we believe the EZ36’s dependability is average to above average. There are no major design flaws or issues with the engine. Still, no engine is perfect, and the 3.6L flat-6 Subaru engine is no exception.
The EZ36’s design leaves a lot of room for potential oil leaks. It’s normal wear and tear that all engines experience with age and mileage. However, because of the area of the 3.6 engine that requires sealing, leaks are more likely. Otherwise, the serpentine belt tensioner is a common source of concern, but it is a minor issue in the grand scheme of things. Finally, timing chain tensioners are a fairly common issue on the EZ36.
Of course, a large part of Subaru EZ36 dependability is determined by maintenance. Use high-quality oils, change fluids on schedule, and fix problems as they arise. It’s all basic stuff that any engine should do. But if you do all of this on the EZ36 3.6 flat-6, chances are it will live a long and reliable life. With proper maintenance, the engine should be able to go beyond 200,000 miles.
Summary of the Subaru EZ36 Engine
In the 2008 Tribeca, EZ36 engines made their debut. It was then incorporated into the 2010-2019 Subaru Outback and Legacy models. The 3.6-liter flat-6 boxer engine produces 256 horsepower and 247 pound-feet of torque. Numbers that are commendable for its natural aspiration design. Aside from its unique flat-6 configuration, the EZ36 specs are fairly standard for a 6-cylinder engine.
Oil leaks and serpentine belt tensioners are two common issues. None of these are true design flaws, but rather problems and maintenance issues that many engines encounter as they age. Timing chain tensioner issues do occur, but they are uncommon.
Overall, the Subaru EZ36 has a lot to offer most people. The engine may not be as visually appealing as some other Subaru boxer engines. It does, however, have a good balance of performance, dependability, and longevity. With proper maintenance, EZ36 flat-6 engines can live very long and reliable lives.