The Subaru 2.4 liter turbocharged engine is considered one of the best engines from this car company and powers the Subaru Ascent, Outback, and Legacy vehicles. It emerged after the discontinuation of the 3.6-liter engine, and in search of a powerful motor that provides fuel efficiency and reliability, this engine was made.

The 2.4-liter turbocharged engine provides 260 horsepower and 277 lb-ft of torque in any of these three vehicles, although the fuel economy is different. In the Subaru Ascent, you get 27 mpg on the highway and 5,000 pounds of towing capacity. 

Then the Subaru Outback offers the same 27mpg on the highway but half the towing capacity as the Ascent. And with the Subaru Legacy, you get up to 32 mpg on the highway, which is impressive fuel efficiency.

Is the 2.4 Liter Turbocharged Engine Reliable? 

The 2.4-liter engine is reliable, and this is not surprising as Subaru has a reputation for making high-quality cars. Although known for its boxer engine designs and all-wheel-drive layouts, the 2.4-liter engine is very different.

There have been no reports on problems with this engine, unlike with other Subaru engine types like the boxer engine. Aside from regular maintenance and changing components after it surpasses 150,000 miles, there are no significant issues with using this engine. So, you can fully rely on it.

Common Problems with Subaru Turbocharged Engine 

Although Subaru turbocharged engines are built for reliability and long-lasting use, there are a few problems that might require your attention. Remember that no engine or vehicle is perfect, and there will be some faults regardless of how reliable it is, as is the case with the 2.4-liter engine. These problems are found in other turbocharged engines, like the 2.0- and 2.5-liter.

Oil Starvation 

Many customers have complained about oil starvation in the turbocharged engine caused by the small filter. Because of its small size, it can’t filter a lot of oil, regardless of the type of oil you choose. This further leads to clogging, and the filter goes into bypass mode. 

You can prevent this problem by checking the oil supply bolts during the oil change every 60,000 miles or earlier if you use your car often. You should also change the oil every 3,750 miles to prevent other problems.


There are different reasons why your 2.4-liter engine might misfire. It might be because of a damaged ringland on the pistons, boost leaks, or a tight valve, further leading to burnt valves. 

If your engine is misfiring each time you start the car, you should immediately take it to a professional mechanic. Ignoring it can lead to a much bigger problem, causing you to spend money fixing it.  

Gasket Oil Leaks 

Another problem common with turbocharged engines is gasket oil leaks, but keep in mind that this is also normal. Gaskets are subject to wear and tear, and after about 100,000 miles, you should check for leaks since they would have deteriorated with constant use. 

If you notice smoke coming out of the engine bay, this is the top sign that your valve cover gasket is leaking. You can then check the gasket for leaks and hire a professional mechanic to replace it for you. Another vital sign is the smell of burning oil in your car. 

Rod Bearing Failure

Finally, you might also have to deal with rod bearing failure on your Subaru 2.4 liter engine. It connects rods to the crankshaft and takes on a lot of abuse while you drive. When there’s trouble with your oil flow, the rod bearing gets affected first, significantly if you don’t consistently change your oil.

If the rod bearings fail, they cause the rods to hit the cylinder walls while you drive, and in the worst case, can lead to a hole in the engine block. You can identify the problem when you hear knocks in your engine or metal shavings in your oil. If this is the case, have your car checked out by a professional mechanic as soon as possible.


The Subaru 2.4 liter turbocharged engine can last for over 150,000 miles with proper maintenance, and it is the same maintenance that would prevent the common problems on our list. From coolant replacement and oil change to cleaning the engine and regular servicing, you can use your engine for a long time with the proper care.

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Pavlo Prannyk
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