THE TOP 5 MAINTENANCE MODS EVERY SUBARU OWNER SHOULD PERFORM

THE TOP 5 MAINTENANCE MODS EVERY SUBARU OWNER SHOULD PERFORM

 

Subarus are some of the most coveted vehicles by enthusiasts due to them being championed rally vehicles in the world rally circuit.  They are highly receptive to engine, suspension, and drivetrain modifications, and they are highly versatile with a great variety of different models available to choose from. Other than the BRZ model, Subaru’s all-wheel-drive system makes these vehicles universally suitable to handle all weather conditions and utilities. From enjoying weekend car meets with a WRX, to taking the family on vacation in a new Ascent, there is a Subaru model that will work with just about every purpose. However, like all vehicles, Subarus need maintenance due to the somewhat quirky design of the boxer engine. Staying on top of your maintenance schedule on your Subaru will prolong your engine’s life and performance especially if you plan on having long-term ownership. What is preventative maintenance? This is where you perform needed and required maintenance before your vehicle leaves you stranded out on the road. As busy as our lives are, and as much as we’d like no roadblocks in life while going to work, picking kids up from school, or driving to accommodate an emergency, the inconvenience of breaking down on the side of the road is very expensive, and in many cases, without warning. Preventative maintenance also means taking additional steps to replace some of the surrounding components so that you don’t have to perform additional repairs shortly after a major repair had been made. With that being said, here are our top 5 maintenance mods that we recommend that you perform to your Subaru.

 

AIR OIL SEPARATOR

IAG Performance Air Oil Separator 15-21 WRX

This is one of the most important, if not the most important preventative maintenance upgrade that you can perform to your Subaru. Boxer engines in general whether they be from Subaru or Porsche for example, have a sophisticated positive crankcase ventilation (PCV) system. In Subaru’s case, the oil and vapors will make it past the factory PCV system while coating the cylinders with oil, as well as the intake valves which will lead to carbon buildup. This can lead to many problems. When oil coats your cylinder walls and the tops of your pistons with oil, it lowers your gasoline octane rating which can cause pre-ignition and detonation issues. The beginning symptoms could show signs of higher carbon emissions. Fouled spark plugs will lead to misfires and check engine lights, and with Subarus, prolonged detonation will lead to damaged ring lands on the pistons.

As the name suggests, a proper air/oil separator separates the oil from the air and prevents the oil from entering your intake system. There are many great examples available through the aftermarket, and on our website. Air/oil separators do not add horsepower but maintains and prolongs your Subaru’s performance and engine life and should be upgraded if you don’t have one already.

 

TIMING BELT

Gates Timing Belt Kit 15-21 STI

Another major maintenance requirement that will make, or literally break your engine. A timing belt aligns your camshafts and valvetrain with the firing order of your pistons. A Subaru boxer engine is an interference engine. This means that if the timing belt snaps because you drove past the required maintenance interval, your pistons lose the timing correlation with your valvetrain, making contact with your valves. At minimal, your head(s) will need to come off, and you will need to get new valves, valve guides, seats, springs are recommended, the heads need to be re-decked, and all the work must be performed by a machine shop that really knows what they’re doing and has all the right tooling. In a worse-case scenario but common, the valves will punch a hole through your piston, and you will need a new engine. Either way, if a timing belt snaps, it’s going to cost you thousands of dollars.

Now if your engine is non-interference, and in Subaru’s case, they are not for the most part, you just need a new timing belt. Most cars that have timing belts need them changed every 60-100k miles. Subaru in some models, recommends changing the timing belt every 100k miles or 8 years, whatever arrives first. At minimal and if you can, then you should try to remove a cam cover to do a visual inspection of the belt to see if there are any cracks in the belt. Dry cracks on your timing belt are a ticking time bomb, and your Subaru needs to have the belt replaced yesterday. Driving past your timing belt service is also Roulette with your engine.

In terms of preventative maintenance with timing belts, this is a perfect example. Like most engine designs, getting access to the timing belt requires the removal of vital cooling components which we will address next. But one key component that should be replaced since everything is apart, is your water pump. And this is why in the Gates Timing Belt Kit for example, will include a water pump. You should NEVER try to replace your timing belt only to try and cut corners. YOU MUST replace the required pullies in many available kits as well because a worn-out idler pulley will snap your belt. Timing belt replacements are labor-intensive, and expensive to perform, but you must do it. But pick your poison. New engine, or new timing belt for the next 100k miles?

 

RADIATOR AND COOLANT HOSES

Killer B Motorsport 08-21 All Aluminum Radiator

Both the radiator and the upper and lower coolant hoses in Subaru’s EJ have a failure point. However, this also applies to other Subaru engine models such as the FA, etc. On the OEM radiator, it has plastic upper and lower tanks that host the coolant. The problem is that after years, miles, and countless heat cycles, the heat continuously makes the plastic tanks expand and contract. The problem after a while, as that cracks will develop, and since coolant is highly pressurized when at operating temperatures, it will leak badly. And when your boxer engine gets too hot, please shut it off, have it towed to your preferred mechanic so they can properly repair it. Otherwise, new head gaskets will enter the conversation. How does this happen? If your engine gets so hot from the lack of coolant, the surface of your heads will warp which will cause an uneven mating surface between the head and the short block. Your engine will need to be pulled to make this repair.

The ultimate fix? This would be an all-aluminum radiator. Whether it be from Killer B (pictured above), or other fine examples from Mishimoto, Koyo, CFS, etc., all aluminum units have fully welded aluminum construction with aluminum upper and lower tanks that will not crack when compared to an OEM radiator with the plastic tanks.

 

GrimmSpeed Radiator Hose Kit 04-07 STI / 02-07 WRX

The same wear and tear will happen with your OEM radiator hoses. The OEM units are made with fiber-filled rubber, and over the same time of heat cycles, those fibers inside the rubber will break apart, allowing the rubber to expand.  With earlier WRX and STI models, and especially since they are 20+ years old now, the swelling becomes so large that it either contacts the electrical fan, or tearing open which will leak most of the coolant out. Aftermarket units like GrimmSpeed’s example, are made using heat-resistant multi-layered silicone construction that is much more durable and will not expand the like the OEM units. A must-do if you plan on replacing your radiator.

 

OIL

Motul Oil Change Kit 04-21 STI / 02-14 WRX

You need to stay on top of your oil changes. Especially if you have a modded WRX or STI, and make sure you change that oil every 3k miles. Important performance components such as the turbocharger or aftermarket oil cooler need clean, synthetic oils flowing through the return and drain lines, and your engine’s internals need to operate with as little friction as possible. Dirty oil can get trapped in these smaller areas, and the dirtier the oil becomes, the thicker the oil becomes. Requiring the engine to work harder which can affect the performance. Staying diligent on your oil changes not only prolongs the performance and operation of your engine, but it also helps to keep that dirty oil and buildup flushed out to make sure your engine’s main and rod bearings are free from any micro particles floating in your oil.

 

CLUTCH

South Bend Stage 2 Daily Clutch Kit 15-21 STI

Because your OEM clutch will not last forever, especially if you do the slightest mod such as an intake or cat-back exhaust system that will add 20+ more HP and torque. If you go beyond those mods with a tune, you will surpass the toque levels of your clutch disc, and you will quickly barbeque your clutch. This is why on YouTube for example, there are many videos of cool bros trying to do a burnout in their Corvette, but that’s not tire smoke, that’s the clutch disc.

However, the wrong clutch will totally kill the driving experience. You need to look at your current modifications, but realistically, look at what modifications you plan on doing in the future, and when that timeline will be. Because if you get a clutch that is too aggressive, it can be referred to as on/off. Meaning there is hardly any slippage or feedback, and the clutch just grabs abruptly, as if you just did a low RPM launch. This makes driving your Subaru rather difficult while trying to enjoy the car in the city, or during traffic. Do your research on forums or local social media groups to see what other users experienced with aftermarket clutch kits with daily drivability. South Bend as pictured above, is known to be very drivable and OEM-like in some cases but has the technology and build quality to handle more power and torque levels associated with bolt-on upgrades.

These top 5 maintenance mods and repairs will need to be performed at some point in your Subaru’s timeline. Be responsible and treat your car well so that you can enjoy it especially when it counts such as making it to work on time, or when you need to see a loved one. You don’t want to be left on the side of the road waiting for that $300 tow bill on top of other extensive repairs you may need to perform. If you have the time and means, check your oil, as well as the overall condition of your timing belt, accessory belt, and your cooling components to make sure they are in good working order so that you can remain on the road.