The 1999 Subaru Outback Sport engine holds a special place in the hearts of many car enthusiasts. Known for its reliability and quirky charm, this vehicle combined the practicality of a wagon with the ruggedness of an SUV, all while sporting the heart of a Subaru boxer engine. In this article, we'll dive deep into the specifications of this engine, common problems you might encounter, and, most importantly, how to keep it running smoothly for years to come. So, buckle up and let's get started!

Engine Specifications

The heart of the 1999 Subaru Outback Sport is the 2.2-liter SOHC EJ22 engine. This engine is part of Subaru's renowned EJ series, known for its horizontally opposed, or "boxer," configuration. This design helps keep the engine compact and contributes to a lower center of gravity for the vehicle, improving handling and stability.

Key Specs

• Engine Code: EJ22
• Type: 2.2-liter SOHC (Single Overhead Camshaft)
• Configuration: Horizontally Opposed, 4-Cylinder
• Bore x Stroke: 97 mm x 75 mm (3.82 in x 2.95 in)
• Displacement: 2,212 cc (135 cu in)
• Compression Ratio: 9.5:1
• Fuel System: Multi-Point Fuel Injection
• Power Output: 137 horsepower at 5400 rpm
• Torque Output: 145 lb-ft at 4400 rpm

Boxer Engine Advantages

One of the standout features of the EJ22 engine is its boxer configuration. In a boxer engine, the pistons move horizontally, opposing each other. This design has several advantages:

1. Balance: The opposing motion of the pistons helps to cancel out vibrations, resulting in a smoother running engine.
2. Low Center of Gravity: The horizontal layout allows the engine to sit lower in the chassis, which improves the vehicle's overall stability and handling.
3. Compact Size: The boxer configuration makes the engine shorter than inline or V-shaped engines, which can help with packaging in the engine bay.

Fuel Efficiency

For its time, the 1999 Subaru Outback Sport offered respectable fuel efficiency. The EPA estimated fuel economy was around 22 mpg in the city and 28 mpg on the highway. Of course, real-world fuel economy can vary depending on driving conditions and how well the vehicle is maintained.

Common Problems

Like any vehicle of this age, the 1999 Subaru Outback Sport is prone to certain common problems. Knowing these issues can help you anticipate potential repairs and keep your Outback Sport running its best. Let's dive into some of the typical gremlins you might encounter.

Head Gasket Failure

Ah, the infamous Subaru head gasket issue. This is probably the most well-known problem with older Subaru engines, including the EJ22. The head gasket is responsible for sealing the cylinder head to the engine block, preventing coolant and oil from mixing and maintaining proper compression. Over time, the original head gaskets can degrade and begin to leak. Here's what you need to know:

• Symptoms: Common symptoms include coolant loss, overheating, white smoke from the exhaust, and oil in the coolant or coolant in the oil. You might also notice a sweet smell of coolant inside the car.
• Causes: The original gaskets were made with a material that wasn't as durable as it could be. Overheating can also exacerbate the problem.
• Solutions: The best solution is to replace the head gaskets with an updated, multi-layer steel (MLS) gasket. This design is much more robust and less prone to failure. While you're at it, it's a good idea to have the cylinder heads resurfaced to ensure a perfect seal.

Oil Leaks

Another common issue with older EJ22 engines is oil leaks. Over time, the various seals and gaskets around the engine can dry out and crack, leading to leaks. Keep an eye out for these potential leak sources:

• Valve Cover Gaskets: These are a common source of leaks, as the rubber gaskets can harden and shrink over time. Symptoms include oil dripping onto the exhaust manifold (you'll smell it!) and general oil seepage around the valve covers.
• Rear Main Seal: This seal prevents oil from leaking out the back of the engine, where the crankshaft connects to the transmission. A leaking rear main seal can be tricky to diagnose, as the oil often ends up on the transmission or bellhousing.
• Oil Pan Gasket: The oil pan gasket seals the oil pan to the engine block. Leaks here are usually pretty obvious, as you'll see oil dripping from the bottom of the engine.
• Solutions: Replacing the affected gaskets and seals is the best way to address oil leaks. Be sure to use quality parts and follow the proper torque specifications when installing new gaskets.

Catalytic Converter Issues

As the 1999 Subaru Outback Sport ages, the catalytic converter can become less effective or even fail altogether. The catalytic converter is responsible for reducing harmful emissions from the exhaust. Here's what to watch for:

• Symptoms: Common symptoms include a check engine light (usually with a P0420 code), poor fuel economy, and a sulfurous smell from the exhaust.
• Causes: Over time, the catalyst material inside the converter can become clogged or degraded. Oil leaks or coolant leaks can also damage the converter.
• Solutions: Replacing the catalytic converter is usually the best option. Be sure to use a high-quality replacement converter that is designed for your vehicle.

Oxygen Sensor Failure

The oxygen sensors (O2 sensors) play a crucial role in the engine's fuel management system. They monitor the oxygen content in the exhaust and provide feedback to the engine control unit (ECU), which adjusts the air-fuel mixture accordingly. When O2 sensors fail, it can lead to a variety of problems:

• Symptoms: Common symptoms include a check engine light, poor fuel economy, rough idling, and hesitation during acceleration.
• Causes: O2 sensors can fail due to contamination, age, or damage. Oil leaks or coolant leaks can also shorten their lifespan.
• Solutions: Replacing the faulty O2 sensor is the best fix. There are usually two O2 sensors: one upstream of the catalytic converter and one downstream. It's often a good idea to replace both at the same time.

Idle Air Control Valve Problems

The Idle Air Control (IAC) valve regulates the amount of air that bypasses the throttle plate when the engine is idling. This helps maintain a stable idle speed. If the IAC valve becomes dirty or fails, it can cause idling problems:

• Symptoms: Common symptoms include a rough idle, stalling, and difficulty starting the engine.
• Causes: The IAC valve can become clogged with carbon deposits over time. Electrical problems can also cause it to fail.
• Solutions: Sometimes, you can clean the IAC valve with a throttle body cleaner. However, if cleaning doesn't solve the problem, you'll need to replace it.

Maintenance Tips

Keeping your 1999 Subaru Outback Sport running smoothly requires regular maintenance. Here are some tips to help you keep your ride in tip-top shape:

Regular Oil Changes

This is the most basic but also the most important maintenance task. Change your oil and filter every 3,000 to 5,000 miles, depending on your driving conditions. Use a high-quality oil that meets Subaru's specifications.

Cooling System Maintenance

The cooling system is critical for preventing overheating. Flush and refill the coolant every two to three years. Also, inspect the hoses and radiator for leaks or damage.

Timing Belt Replacement

The EJ22 engine has a timing belt that needs to be replaced at regular intervals, usually around 60,000 to 100,000 miles. If the timing belt breaks, it can cause serious engine damage. Don't skip this important maintenance item!

Spark Plug Replacement

Replace the spark plugs every 30,000 miles or as recommended in your owner's manual. New spark plugs can improve fuel economy and engine performance.

Air Filter Replacement

A clean air filter is essential for proper engine performance. Replace the air filter every 12,000 to 15,000 miles, or more often if you drive in dusty conditions.

Check and Replace Fluids

Regularly check and top off all fluids, including brake fluid, power steering fluid, and transmission fluid. Replace these fluids as recommended in your owner's manual.

Upgrades and Modifications

If you're looking to enhance the performance or appearance of your 1999 Subaru Outback Sport, there are plenty of upgrades and modifications available. Here are a few ideas:

Performance Upgrades

• Exhaust System: A cat-back exhaust system can improve exhaust flow and increase horsepower.
• Intake System: A cold air intake can improve airflow to the engine and boost performance.
• ECU Tuning: A custom ECU tune can optimize the engine's performance for your specific modifications.

Suspension Upgrades

• Struts and Shocks: Upgrading to performance struts and shocks can improve handling and ride quality.
• Sway Bars: Upgrading the sway bars can reduce body roll and improve cornering.
• Lift Kit: If you want to increase ground clearance and improve off-road capability, a lift kit is a great option.

Cosmetic Upgrades

• Wheels and Tires: New wheels and tires can dramatically change the look of your Outback Sport.
• Grille: A custom grille can give your vehicle a unique appearance.
• Lighting: Upgrading to LED headlights and taillights can improve visibility and modernize the look of your car.

Conclusion

The 1999 Subaru Outback Sport engine, specifically the EJ22, is a reliable and characterful powerplant. While it does have some common problems, such as head gasket failures and oil leaks, these issues can be addressed with proper maintenance and timely repairs. By following the maintenance tips outlined in this article and addressing any problems promptly, you can keep your Outback Sport running smoothly for many years to come. Whether you're a long-time Subaru enthusiast or new to the brand, the 1999 Outback Sport offers a unique blend of practicality, reliability, and quirky charm that's hard to resist. So, keep wrenching, keep exploring, and keep enjoying the ride!