Hey guys! Are you experiencing some issues with your Subaru Forester 2.0 diesel turbo? You're not alone! This engine, while generally reliable, can sometimes throw a curveball. But don't worry, we're going to dive into the common problems, potential solutions, and how to keep your turbo spinning happily for years to come. Let's get started!

Common Problems with the Subaru Forester 2.0 Diesel Turbo

The Subaru Forester 2.0 diesel turbo engine is a popular choice, known for its decent fuel economy and reasonable power. However, like all engines, it has its potential pitfalls. Identifying these common issues early can save you a lot of headaches and money down the road.

1. Turbocharger Failure

This is arguably the most concerning issue. A failing turbocharger can manifest in several ways:

• Loss of Power: The most obvious symptom. Your Forester will feel sluggish, especially when accelerating. You might notice it struggling to climb hills or overtake other vehicles.
• Excessive Smoke: Blue or grey smoke from the exhaust is a telltale sign of oil leaking into the turbocharger. This oil is then burned in the engine, producing the smoke.
• Whining or Screeching Noises: Unusual noises coming from the engine bay, particularly during acceleration, could indicate worn turbocharger bearings.
• Check Engine Light: The engine management system will often detect issues with the turbocharger and trigger the check engine light.

Why does this happen? Turbocharger failure can be caused by several factors, including:

• Oil Starvation: The turbocharger relies on a constant supply of clean oil for lubrication and cooling. Insufficient oil levels or dirty oil can lead to bearing failure.
• Foreign Object Damage: Debris entering the turbocharger can damage the turbine blades, leading to imbalance and failure.
• Overboosting: Exceeding the turbocharger's maximum boost pressure can put excessive strain on its components.
• Wear and Tear: Like any mechanical component, the turbocharger will eventually wear out over time.

2. Diesel Particulate Filter (DPF) Issues

The DPF is designed to trap soot particles from the exhaust. However, it can become clogged over time, leading to:

• Reduced Engine Performance: A clogged DPF restricts exhaust flow, reducing engine power and fuel economy.
• DPF Warning Light: The DPF warning light on the dashboard will illuminate.
• Forced Regeneration: The engine may attempt to regenerate the DPF by injecting extra fuel into the exhaust. This can lead to increased fuel consumption and a burning smell.
• Limp Mode: In severe cases, a clogged DPF can trigger limp mode, restricting engine speed and power to prevent further damage.

Why does this happen? DPF issues are often caused by:

• Short Journeys: Frequent short journeys don't allow the DPF to reach the high temperatures required for regeneration.
• Incorrect Oil: Using the wrong type of engine oil can contribute to DPF clogging.
• Faulty Sensors: Faulty DPF sensors can prevent regeneration from occurring.

3. EGR Valve Problems

The Exhaust Gas Recirculation (EGR) valve recirculates a portion of the exhaust gas back into the intake manifold to reduce emissions. However, it can become clogged with carbon deposits, leading to:

• Rough Idling: The engine may idle unevenly or stall.
• Poor Acceleration: The engine may hesitate or stumble during acceleration.
• Increased Emissions: The EGR valve may not function correctly, leading to increased emissions.
• Check Engine Light: The engine management system will often detect issues with the EGR valve and trigger the check engine light.

Why does this happen? EGR valve problems are primarily caused by:

• Carbon Buildup: Exhaust gas contains carbon particles that can accumulate in the EGR valve over time.

4. Fuel Injector Issues

Fuel injectors are responsible for delivering fuel into the engine cylinders. Problems with the fuel injectors can cause a range of symptoms, including:

• Poor Fuel Economy: Inefficient fuel delivery can lead to increased fuel consumption.
• Misfiring: The engine may misfire, resulting in a rough running condition.
• Difficulty Starting: The engine may be difficult to start, especially in cold weather.
• Excessive Smoke: Faulty fuel injectors can cause incomplete combustion, leading to excessive smoke from the exhaust.

Why does this happen? Fuel injector issues can be caused by:

• Contaminated Fuel: Dirty fuel can clog the fuel injectors.
• Wear and Tear: Fuel injectors can wear out over time.

5. Sensor Failures

Modern diesel engines rely on a network of sensors to monitor various parameters. Failing sensors can provide incorrect data to the engine management system, leading to various problems. Common sensor failures include:

• Mass Airflow (MAF) Sensor: Measures the amount of air entering the engine.
• Oxygen (O2) Sensor: Measures the amount of oxygen in the exhaust gas.
• Crankshaft Position Sensor: Monitors the position of the crankshaft.
• Camshaft Position Sensor: Monitors the position of the camshaft.

Symptoms of sensor failures can include:

• Poor Engine Performance: Reduced power, poor acceleration, and rough idling.
• Check Engine Light: The engine management system will often detect sensor failures and trigger the check engine light.
• Increased Fuel Consumption: Incorrect sensor readings can lead to inefficient fuel delivery.

Solutions and Prevention

Now that we've covered the common problems, let's talk about solutions and, more importantly, how to prevent these issues from occurring in the first place. A little preventative maintenance can go a long way in keeping your Subaru Forester 2.0 diesel turbo running smoothly.

1. Turbocharger Care

• Regular Oil Changes: Use high-quality, fully synthetic oil that meets Subaru's specifications. Change the oil and filter at the recommended intervals.
• Use the Right Oil Filter: A quality oil filter ensures clean oil reaches the turbocharger, preventing premature wear.
• Let the Engine Warm-Up: Avoid hard acceleration until the engine has reached its operating temperature. This allows the oil to properly lubricate the turbocharger bearings.
• Cool-Down Period: After a long drive or hard acceleration, let the engine idle for a minute or two before shutting it off. This allows the turbocharger to cool down and prevents oil coking.
• Check for Leaks: Regularly inspect the turbocharger for oil leaks. Address any leaks promptly to prevent oil starvation.

2. DPF Maintenance

• Longer Journeys: Take your Forester on longer journeys at least once a month to allow the DPF to regenerate passively.
• Use the Correct Oil: Use low-ash engine oil that is specifically designed for vehicles with DPFs.
• DPF Cleaner: Consider using a DPF cleaner periodically to help remove soot deposits.
• Professional Cleaning: If the DPF becomes severely clogged, consider having it professionally cleaned.

3. EGR Valve Cleaning

• Regular Cleaning: Periodically clean the EGR valve to remove carbon deposits. You can use a specialized EGR valve cleaner.
• Professional Cleaning: If the EGR valve is severely clogged, consider having it professionally cleaned by a mechanic.

4. Fuel Injector Maintenance

• Use High-Quality Fuel: Use high-quality fuel from reputable gas stations.
• Fuel Additives: Consider using fuel additives to help clean the fuel injectors.
• Fuel Filter Replacement: Replace the fuel filter at the recommended intervals.

5. Sensor Maintenance

• Regular Inspections: Have the sensors inspected periodically by a mechanic.
• Prompt Replacement: Replace any faulty sensors promptly.

Regular Maintenance is Key

Keeping your Subaru Forester 2.0 diesel turbo in top condition requires regular maintenance. Don't skip scheduled services, and address any problems as soon as they arise. This will help prevent more serious and costly repairs down the road.

Servicing Checklist

• Oil and Filter Change: Every 6,000 miles or 6 months
• Air Filter Replacement: Every 12,000 miles or 12 months
• Fuel Filter Replacement: Every 24,000 miles or 24 months
• DPF Inspection: Every 24,000 miles or 24 months
• EGR Valve Inspection: Every 36,000 miles or 36 months

Conclusion

The Subaru Forester 2.0 diesel turbo can be a reliable and enjoyable vehicle when properly maintained. By understanding the common problems and taking preventative measures, you can keep your Forester running smoothly for many years to come. Remember, regular maintenance is the key to a long and happy life for your turbo diesel! If you're not comfortable performing these tasks yourself, don't hesitate to take your Forester to a qualified mechanic.