How to Fix an Intake Leak on Your 2020 Subaru WRX

How to Fix Engine Issues

The 2020 Subaru WRX, while a performance-oriented vehicle, can experience engine issues, primarily related to intake leaks. These leaks can lead to a lean condition, misfires, and even engine damage if left unaddressed. According to owners, addressing these issues promptly is crucial for maintaining engine health. As one owner shared: "I’m tuning so the car knows how to properly deal with the AFR and the timing issue at high rpm. Saving an engine from blowing is worth it to me" (source. This guide will walk you through diagnosing, fixing, and preventing intake leaks and other engine-related problems specific to this vehicle.

Symptoms

One of the primary symptoms owners report is a lean condition. This happens when the engine receives too much air and not enough fuel. A lean condition can cause the engine to run hotter than normal, potentially leading to misfires and pre-ignition.

Another common symptom is engine misfire. Misfires occur when one or more cylinders in the engine fail to fire properly. This can result in a rough idle, decreased power, and poor fuel economy. Misfires can be caused by a variety of issues, but intake leaks are a significant contributor.

Oil contamination and starvation are also mentioned in discussions related to potential engine wear and tear. While not directly caused by an intake leak, it's important to consider that a lean condition can exacerbate wear over time. Similarly, spun bearings in the engine are extreme cases, but highlight the importance of maintaining proper engine health and addressing issues promptly. One owner even referenced getting a quote after discovering a spun bearing: "I made a post a couple days ago about my engine having a spun bearing , i got it towed to the shop today and this is the quote. This is a local shop that specializes in these type of cars and such." (source.

Finally, unusual engine wear can be a symptom of an underlying problem. Catching issues early can prevent more serious damage down the line. Monitoring your oil regularly and paying attention to any unusual engine noises or performance issues can help you identify potential problems before they escalate.

Most Likely Cause

Based on owner reports, the most likely cause of these engine issues is an intake leak. An intake leak introduces unmetered air into the engine, disrupting the air-fuel ratio. This disruption primarily leads to a lean condition, which can then trigger a cascade of other problems. The turbo inlet hose can be a common source of leaks.

Intake leaks can occur in various locations, including the intake manifold gasket, vacuum lines, or even the turbo inlet hose. Cracks, loose connections, or damaged seals can all allow air to enter the engine.

According to one owner, a torn turbo inlet hose led to significant performance issues: "My original turbo inlet hose was torn. I had a Perrin unit laying around that came free with some used parts i ordered a year ago." (source. Replacing the damaged hose resolved the issue and restored proper engine function.

How to Diagnose

Diagnosing an intake leak requires a systematic approach. Begin with a visual inspection of all intake components, looking for any obvious cracks, loose connections, or damaged hoses. Pay close attention to the intake manifold gasket, vacuum lines, and the turbo inlet hose.

Next, perform a smoke test. This involves introducing smoke into the intake system and observing where it escapes. The location of the smoke leak indicates the source of the intake leak. You can purchase a smoke machine or create a DIY version using readily available materials.

You will need the following tools for diagnosing intake leaks:

• Smoke machine (or DIY equivalent)
• Spray bottle with soapy water
• Mechanic's stethoscope
• Basic hand tools (screwdrivers, wrenches)
• OBD-II scanner to read fault codes

Step-by-Step Fix

Follow these steps to address the intake leak and related engine issues:

1. Inspect the Intake System: Visually inspect the intake manifold, vacuum lines, and turbo inlet hose for any cracks, loose connections, or damage. Check the intake manifold gasket for signs of wear or leaks.

2. Perform a Smoke Test: Use a smoke machine to introduce smoke into the intake system. Observe where the smoke escapes to identify the source of the leak. Alternatively, spray soapy water on potential leak areas while the engine is running. Bubbles will form where there is a leak.

3. Replace Damaged Components: Replace any cracked or damaged hoses, gaskets, or seals. Ensure that all connections are tight and secure. When replacing the turbo inlet hose, make sure it is the correct length to avoid further issues, as stated by one owner who said "I had a Perrin unit laying around that came free with some used parts i ordered a year ago. I used it but i discovered when installing the turbo that it was a bit short." (source.

4. Check Vacuum Lines: Inspect all vacuum lines for cracks or leaks. Replace any damaged lines and ensure they are properly connected. Vacuum leaks can cause a variety of engine problems, including a lean condition.

5. Tighten Connections: Ensure that all connections in the intake system are tight and secure. Loose connections can allow air to leak into the engine.

6. Clean the oil cooler: As the engine might have previous damage to the bearings, it's important to replace the oil cooler. As one owner shared: "Oil cooler is a good idea since old bearing material can hang out there until it eventually comes loose and wrecks the new engine. The rest seems excessive" (source.

7. Clear Fault Codes: After addressing the intake leak, use an OBD-II scanner to clear any fault codes that may have been triggered by the lean condition or misfires.

8. Test Drive: Take the vehicle for a test drive to ensure that the engine is running smoothly and that the symptoms have been resolved. Monitor engine performance and fuel economy to confirm that the repair was successful.

Parts and Tools Needed

• Intake manifold gasket (Part number varies depending on year and model)
• Vacuum lines (Assorted sizes)
• Turbo inlet hose (Replacement aftermarket hoses available)
• Smoke machine (Optional)
• Spray bottle with soapy water
• Mechanic's stethoscope
• Basic hand tools (screwdrivers, wrenches)
• OBD-II scanner

Real Owner Costs

The cost of fixing an intake leak can vary depending on the severity of the leak and the parts that need to be replaced. DIY repairs can be relatively inexpensive, while professional repairs can be more costly.

• DIY Repair: Replacing a vacuum line or tightening a loose connection can cost less than $20 in parts. Replacing the intake manifold gasket or turbo inlet hose can cost between $50 and $200, depending on the quality of the parts.
• Professional Repair: A shop will typically charge between $100 and $200 for labor to diagnose and repair an intake leak. The total cost can range from $200 to $500 or more, depending on the parts that need to be replaced. Some shops that specialize in the vehicle may charge a premium, as referenced by an owner: "This is a local shop that specializes in these type of cars and such." (source.

For example, replacing a turbo inlet hose yourself might cost $100 for the part. However, having a shop do it could cost $100 for the part plus $150 for labor, totaling $250.

Prevention

Preventing intake leaks involves regular maintenance and inspection of the intake system.

• Regular Inspections: Inspect the intake manifold, vacuum lines, and turbo inlet hose for any signs of wear or damage. Check for cracks, loose connections, or damaged seals.
• Proper Maintenance: Follow the manufacturer's recommended maintenance schedule for your vehicle. This includes replacing air filters and other components that can affect engine performance.
• Avoid Harsh Chemicals: Avoid using harsh chemicals or solvents when cleaning the engine bay. These chemicals can damage rubber hoses and seals, leading to leaks.
• Regular Oil Changes: Change your oil regularly as per the manufacturer's recommendations. One owner noted "I go every 5k using Pennzoil Platinum 5w-30, though it's just a stock engine/tune and more than half are highway miles" (source, highlighting the importance of regular oil changes.

What Owners Say

Real experiences from SUBARU owners:

Owner Experiences

"I had a Perrin unit laying around that came free with some used parts i ordered a year ago. I used it but i discovered when installing the turbo that it was a bit short." — Technotitclan (source)

"My original turbo inlet hose was torn. I had a Perrin unit laying around that came free with some used parts i ordered a year ago." — Technotitclan (source)

"I’m not tuning for the intake specifically. I’m tuning so the car knows how to properly deal with the AFR and the timing issue at high rpm." — imustknownowI (source)

Pro Tips from Owners

💡 "Nobody can predict how reliable that engine will be, could last 5 miles or 250,000+. My advice is just to take reasonable precautions (don’t lug it or bag on it when it’s cold etc) and do maintenance on or ahead of time, it’s all you can do." — Fit_Equivalent3610 (source)

💡 "If the pistons aren't cracked you can often reuse them. Look for ringland cracks when you disassemble it and make sure you keep track of which piston goes where." — grizzdoog (source)

💡 "My advice is just to take reasonable precautions (don’t lug it or bag on it when it’s cold etc) and do maintenance on or ahead of time, it’s all you can do." — Fit_Equivalent3610 (source)

FAQ

Q: How long does it take to fix an intake leak?

A: Depending on the severity of the leak and your mechanical skill level, fixing an intake leak can take anywhere from 1 to 4 hours. A simple vacuum line replacement may take as little as an hour, while replacing the intake manifold gasket or turbo inlet hose can take several hours.

Q: Can I drive with an intake leak?

A: While it is technically possible to drive with an intake leak, it is not recommended. Driving with an intake leak can cause a lean condition, which can damage the engine over time. Additionally, a lean condition can lead to misfires, reduced power, and poor fuel economy.

Q: Is this a common issue on the 2020 Subaru WRX?

A: While not every 2020 Subaru WRX will experience an intake leak, it is a relatively common issue, particularly on vehicles with higher mileage or those that have been modified. The turbo inlet hose and intake manifold gasket are particularly prone to leaks.

Q: DIY vs mechanic - what's recommended?

A: If you are comfortable working on cars and have the necessary tools, you can likely fix an intake leak yourself. However, if you are not experienced with automotive repair, it is best to take your vehicle to a qualified mechanic. Diagnosing and repairing an intake leak can be challenging, and it is important to ensure that the repair is done correctly to avoid further engine damage. If the issue requires tuning, it is best to consult a qualified professional tuner, as suggested by one owner: "I’m not tuning for the intake specifically. I’m tuning so the car knows how to properly deal with the AFR and the timing issue at high rpm." (source.