If you’ve been thinking of getting a used Subaru, you just came to the right place. We bet that you want to learn more about the Subaru engine problems, and which models are worth avoiding.
- Subaru Quality Record
- Subaru Boxer Engines
- Most Common Subaru Engine Problems
- Head Gasket Problems
- Oil Starvation Problems
- Oil Consumption Problems
Subaru traditionally has a perfect track record when it comes to making quality cars. But sometimes, even the best carmakers make mistakes, and they brought certain models or products to market in too much of a hurry.
Rushing production often translates into bad build quality and factory defects. Some of these problems can be critical and could ruin a company’s reputation that has been polished for decades.
There are a couple of Subaru engines that don’t fit the bill. There is something about these motors that need to be taken into consideration before purchasing any Subaru vehicle. You should know first and foremost about what you’re getting yourself into. Naturally, you don’t want to lose a lot of money in your car, which later turns out to be a basket case.
You don’t want to get yourself a lemon. Lemons are the worst cars that you could get, but it’s those good-looking and newer cars that are even more terrible. They hide many issues that people before you haven’t yet managed to solve. If you are a problem solver by nature, then this could be the perfect buy for you.
In this article, we are going to cover a lot about Subarus. We are going to discuss the boxer motor. Then we will also be going to discuss Subaru engine problems, and which engines you should avoid. So, if you want to learn more about Subaru engine problems. Follow along.
Subaru Quality Record
When we hear Subaru, the first assumption that we make is their record for quality is almost impeccable. Subaru has been in the US market for decades now and has almost always delivered well-built cars.
Subaru cars were considered almost bulletproof because their engines could easily go forever without any major concerns. This quality and attention for craftsmanship lasted until the mid-2000s.
This was the time when Subaru introduced new models to expand their market in the US. They needed something else other than the Impreza, to satisfy US customers and their demand for Subarus.
Also, there was a significant number of recalls in certain Subaru models. A recall is usually when a car has some factory defects that could be life-threatening in most situations. Examples include a problem with airbags, engine problems, transmission woes, and more.
Recent Subaru models don’t have a good track record and they had many recalls. This is important to know because you don’t want a model that was exposed to some factory-made flaws.
The Subaru Boxer Engine
Subaru is quite well-known for its use of boxer motors. Boxer motors work differently than inline or V8 engines. Although, they do follow the same principles as other internal combustion engines and use the same pistons, crankshaft, and spark principle.
Boxer engines are laid out differently compared to other piston designs. The boxer engine works in a way that the engine lies flat with the pistons at a 180-degree angle. Their shape is basically flat, and they are much wider than V8 engines.
The crankshaft is placed in the middle of the motor and the pistons are laid flat on both sides.
They look like they are boxing when they work, like two boxing sparring partners. That’s where the ‘boxer’ name for the engine comes from. Not many automakers use this engine layout, and this makes Subaru cars unique and special.
Boxer Engine Advantages
There are many advantages with the boxer engines. Some of them include its short length and the low center of gravity. This is very useful when it comes to cooling.
Another useful thing is that there is a lot of space in the front of the engine, and you can easily access the pulley and the serpentine belts. This is important because, in V8 or straight-six engines, the whole engine needs to come out from the car. That’s for these things to be properly addressed, serviced, and replaced.
The layout of the boxer engine also allows fewer vibrations to reverberate during the combustion process. Fewer vibrations mean better comfort for the passengers and a smoother driving experience. This matters, because at the end of the day, what’s the point of driving a car that doesn’t ride comfortably?
Boxer Engine Disadvantages – Subaru Engine Problems
There are plenty of advantages to the boxer design. But there are also a few disadvantages when we discuss flat engines or boxers, as people love to call them.
One of the disadvantages of this design is its width. So, to accommodate a wider engine, you need to have a wide engine bay.
Moreover, the stroke is too short and piston rods could fail more often. The stroke in these engines needs to be short in order to accommodate the flat boxer engine in the engine bay. And because these rods are a lot shorter than in regular inline-four engines, they can start to develop some issues, and in some cases break, because their foundation is too thin and cannot hold a lot of stress. That’s why upgrading your rods if you are planning to produce more power from the engine, is a good idea.
The bulkier footprint makes the engine difficult to work on, as well. So, if you want to change your spark plugs, it’s going to be very difficult to access the engine from the side. That’s because the engine is so close, it’s almost touching the frame rails. This can result in more expensive repair bills, and as the engine needs to come out entirely for some repairs to be performed. Thus, it’s not DIY-friendly for some maintenance work.
Another disadvantage with this engine is that there have to be two engine heads. When you need to manufacture two engine heads per engine instead of one, it means that this engine is going to be more expensive to manufacture compared to a straight four or straight-six engine.
Boxer Engine Applications
The Boxer design layout isn’t anything new and has been used for a very long time. It was adopted in motorcycles, aviation engines, and cars. The most notable vehicles that had a boxer engine are probably the VW Beetle and the VW T1 van. We all know the hippie van from the 60s, right?
These cars made the Boxer engine very popular, but not to forget the Porsche 911. Porsche is still to this day using a flat-six engine in their 911 Carrera. Basically, Subaru and Porsche are among the few manufacturers that are still using this engine design in mass production.
And that is what makes their cars unique. Because you cannot find another car that is running a flat boxer engine anywhere in the world.
Personally, I think that this engine design is a bit underrated, and deserves more praise than other engine configurations like the V8. I really hope that more carmakers will start implementing some of these design features in their cars, and will start making boxer engines again.
But for now, let’s continue from where we stopped and that is the subject around Subaru engine problems. This is the reason why you are here after all.
What Are The Most Common Subaru Engine Problems?
In the past, Subaru was proud of the flat piston engines, and they are still considered as one of the best engines out there. These engines could easily go for 200,000 miles with no problems whatsoever. But with their recent modifications, they’ve managed to ruin their reputation. Their engines are not that reliable as they used to be.
The Subaru EJ25 is one of the most common engines that Subaru uses in their vehicles. This engine came in two variations – a naturally aspirated boxer engine 2.5-liter with a double overhead camshaft, and a compression ratio of 9.5:1.
Or, you could get a 2.5-liter single overhead camshaft naturally aspirated engine, with a compression ratio of 10:1. This ratio is pretty high compared to its use as a road car. As for power, this engine could produce a decent 162 hp.
The good thing with this motor was that it delivered a lot of torque – 167 lb. ft to be exact.
This engine was installed in many Subaru models. Namely, we have the Impreza, Outback, Forester, Baja, and several others. It was even used by Saab in their Saab 9-2x.
Since its inception, however, the EJ 25 was plagued by many problems. These problems included oil burning, oil starvation, and head gasket issues. These problems were not caused by heavy mileage and abuse, but because of the engine’s design and its poor engineering. Also, it had plenty of quality issues. Now let’s discuss these Subaru engine problems one by one.
EJ25 Head Gasket Subaru Engine Problems
Almost all the EJ 25 engines are facing head gasket problems. This issue is more common with the early models. This is the case because Subaru used low-quality head gasket materials that were made out of composites.
Oil In Coolant – Subaru Engine Problems
These gaskets were so badly made, that they had allowed the oil and coolant to mix with each other. Hence, creating a big sludgy mess inside your engine.
When oil and coolant mix, they stop doing their job properly. Remember that motor oil is there to lubricate the engine, and the coolant is there to cool the engine down. When they mix, for example when the coolant gets inside the oil, the oil does not lubricate the engine well enough.
There is then either no lubrication, or there is a lack of it. The engine will potentially start to wear its components prematurely. For example, piston rings may start to fail. Or, the camshaft bearings can wear off prematurely. Many problems can arise with this issue.
Also, when there is oil in the coolant, the coolant will not function properly, and the car will eventually start to overheat. Many Subaru vehicles have this problem.
Oil And Coolant In The Combustion Chamber
Oil or coolant can also get inside the combustion chamber, and will then start to burn. When oil burns, you can clearly see black smoke coming out of the exhaust. There will be clouds of smoke.
If the coolant burns in the combustion process, there will instead be white plumes of smoke coming out of the exhaust of the car. This white smoke is a clear sign that the coolant is burning.
Coolant Leaks From The Outside
In these engines, it may lead to head gaskets failing, and the coolant starts to leak from outside of the engine. These leaks will diminish your coolant levels inside the engine and it will start to overheat. This can result in catastrophic engine damage in the process.
What To Pay Attention To
If you have a Subaru that has an EJ25 engine it is important to pay attention to the temperature gauge and make sure that it’s not going above the recommended thresholds. If your engine overheats, or if it doesn’t have enough lubrication, it can easily scrap your engine.
This problem, when detected, it’s a good idea for you to take your car to a local Subaru mechanic and let them deal with this problem. This is a painstaking process and can cost a lot of money. Namely, because your engine needs to come out from the engine bay. This is for the mechanic to have a workable environment and be able to reach the bolts that are below the car. This is one of the downsides of boxer engines – never enough space to work on them.
Cost To Fix Subaru Engine Problems
Because of this, the changing of the head gasket can cost from $1,000 up to $1,500. The parts cost is relatively low, but the engine needs to come out and that involves a lot of labor hours. There’s also the option of if you consider yourself capable and want to try something new. In that case, you can replace this head gasket in your garage.
But first, you will need to have the proper tooling to get the engine out, and then remove and replace the old gasket with a new one. It’s not a beginner-friendly job. So, it’s probably best that you leave this problem to be resolved by professionals.
Symptoms Of A Blown Head Gasket
As we discussed one of the Subaru engine problems is the blown head gasket. When you have a blown head gasket problem, many issues may arise. But if you’re a little bit attentive, you can easily spot this problem and fix it before it becomes too terribly damaged and scraps the engine.
One of the first symptoms is overheating, this happens when the coolant starts to leak in the combustion chamber and causes the engine to burn the coolant. Your temperatures will rise and the engine will start to overheat, resulting in your car stalling. In this situation, it’s a good idea to monitor your coolant levels and make sure that your car never runs low, or out of coolant.
If there is a mix between the oil and the coolant you will have sludgy residue when you pull out your dipstick. If you spot something weird on your dipstick, then your car is probably mixing its coolant and oil. This issue can eat into your bearings and your crankshaft, which results in engine lock and scrapping the engine altogether.
The last symptom is smoke. If the car burns oil you are going to have blue or black smoke. If the car is burning coolant, white smoke will start to come out from your exhaust.
Subaru EJ 25 Oil Starvation
Oil starvation is also one of the Subaru engine problems that bother this engine and its owners. This problem arises because of the design of this engine.
Oil starvation is an issue that comes about when some of the parts of the engine are left without oil. For example, if you are running a car on the track and you pull high G maneuvers. The oil will float from one side to another without properly lubing the engine.
When engine components do not get the proper amount of oil, they start to rub against each other. The friction caused will start eating away the components such as cylinder walls, or crankshaft bearings.
These parts will eventually fail and ruin your engine. The greater the friction, the more grooves, and scratches will occur on these units. Remember that these parts need to be in pristine condition to work properly.
In the case of the Subaru EJ25 engine. The crankshaft bearings will fail if there is less oil than is recommended. If your oil level reaches below the minimum, your crankshaft bearings will not be lubricated, and your engine bearings will start to create friction with the camshaft. The more friction and heat is present, the more damage will be caused to your engine. Your motor will eventually seize.
The best solution for this problem is to always monitor your oil level. And, do not ever let the engine run with insufficient oil that is recommended. If you ignore a situation like this, the engine will eventually lock up and stop working.
The only way around this will be a new crankshaft and bearings. The cost of fixing this issue can run from $1,500 to $2,500. It’s hugely expensive, because of all of the parts that need to be replaced, not to mention the labor that is involved in removing the engine.
Subaru EJ 25 Oil Consumption
Another problem in the long list of Subaru engine problems is the oil consumption on the EJ 25. This issue is another one of Subaru’s engineering mistakes.
The increased oil consumption is attributed to the falling oil control ring on the pistons of the engine. This oil control ring’s job is to keep the oil where it needs to be, and that is out of the combustion chamber.
In the EJ 25 engine, this oil control ring fails very often. When this oil control ring fails, it allows the oil to go inside of the combustion chamber and causes some oil-burning problems to appear. You don’t want this to happen on your Subaru.
Burning oil for too long can total your engine. For example, if you are running your engine like this with low oil. You’re likely going to have an oil starvation issue. Remember that this engine needs more oil than others and doesn’t like to be starved.
In this case, the crankshaft bearings will be left without oil and there will be heat and friction. This then causes your pistons to wobble, and possibly ruin your whole engine.
When a piston does not have the right geometry, it will lose balance and crack the block. This will eventually result in scrapping the whole engine.
This issue is very expensive to fix and can cost more than $1,500. This is the case because the engine has to come out along with all the pistons for the O-ring to be replaced. It’s a big headache in my opinion. You surely want to avoid this happening to your engine.
Subaru Engine Problems – Conclusion
In this article, we have covered a lot about Subaru engine problems. We have discussed Subaru, and their famous boxer engine designs, as well as the up- and downsides of running a boxer engine.
We have also covered all of the Subaru engine problems when it comes to the EJ 25. This engine is plagued by issues. Most of the faults that this engine has are related to the head gasket. It regularly mixes oil and coolant, which then causes the car to overheat.
Another problem is the oil starvation when the bearings inside the crankshaft are left without oil and the engine starves. This causes the crankshaft to incur friction and lock up the engine.
The third major issue is with oil consumption, because of the oil control rings that can fail and cost a fortune to fix.
And now, we come to the end of this article. Should you buy a car with the EJ 25? It’s best not to, in my opinion. You don’t want any major headaches in your life. If you do want to get one, find an engine that has been sorted out and has had these problems patched up to truly enjoy your car.