2020 Subaru WRX Turbo Overheating? Here's How to Fix It

How to Fix Turbo Overheating

Turbo overheating can be a serious issue in your 2020 Subaru WRX, potentially leading to decreased performance and even engine damage. One owner facing a complex repair situation stated, "Have them revise the price to be just a shortblock and turbo, you'll be around $15k and still get 'forged internals'" (source). This guide will walk you through the symptoms, diagnosis, and potential fixes, focusing on the most likely cause based on owner reports: a vacuum leak.

Symptoms

Owners have reported various symptoms that can indicate turbo overheating in their vehicles. While some symptoms are directly related to the turbocharger, others might be more general indicators of engine problems. It's crucial to pay attention to any unusual behavior in your 2020 Subaru WRX to catch potential issues early.

One common symptom is a noticeable decrease in engine power, especially during acceleration. If your car feels sluggish or doesn't respond as quickly as it used to when you press the gas pedal, it could be a sign of turbo inefficiency due to overheating. The turbo may not be able to generate the boost pressure required for optimal performance.

Another indicator can be unusual noises coming from the engine bay. Some owners have described a ticking sound, which might be related to the turbocharger's components expanding and contracting excessively due to high temperatures. Additionally, you might notice a burning smell, signaling that something is getting excessively hot.

Heat emanating from the engine bay after driving, even after a short trip, is another potential symptom. While engines naturally generate heat, an unusually high amount could indicate that the turbo is running hotter than it should. This excessive heat can also affect nearby components, potentially causing damage to power steering lines or other parts.

Finally, some owners have reported experiencing low-speed pre-ignition (LSPI), sometimes referred to as "super knock". This can occur when the air-fuel mixture ignites prematurely in the cylinders, leading to a knocking or pinging sound. LSPI is often associated with high engine temperatures and can be exacerbated by turbo overheating.

Most Likely Cause

Based on available owner data, the most likely cause of turbo overheating in the 2020 Subaru WRX is a vacuum leak. A vacuum leak can disrupt the engine's air-fuel mixture, causing it to run lean. When the engine runs lean, it generates more heat, which can lead to increased turbocharger temperatures.

The turbocharger relies on a precise air-fuel ratio to operate efficiently. A vacuum leak introduces unmetered air into the system, throwing off this balance. This forces the engine to compensate by adding more fuel, which in turn increases combustion temperatures. The higher temperatures put extra strain on the turbocharger, potentially leading to overheating and damage.

Identifying and addressing the vacuum leak is critical to resolving the turbo overheating issue. Vacuum leaks can occur in various locations, including hoses, intake manifold gaskets, and other connections. Thorough inspection and proper repair are necessary to restore the engine's proper air-fuel mixture and prevent further damage to the turbocharger.

How to Diagnose

Diagnosing a vacuum leak requires a systematic approach. Here’s a step-by-step process to help you pinpoint the source of the problem:

1. Visual Inspection: Begin by carefully inspecting all vacuum lines and hoses in the engine bay. Look for any signs of cracks, tears, or disconnections. Pay close attention to the hoses connected to the intake manifold, turbocharger, and other engine components.

2. Listen for Hissing: With the engine running, listen for any hissing sounds coming from the engine bay. A hissing sound is a common indicator of a vacuum leak, as air is being sucked into the system.

3. Smoke Test: A smoke test is an effective way to identify vacuum leaks. This involves using a smoke machine to introduce smoke into the intake system. Any leaks will be revealed by smoke escaping from the affected area.

4. Carburetor Cleaner/Starting Fluid Test: Spray small bursts of carburetor cleaner or starting fluid around potential leak areas, such as vacuum hose connections and intake manifold gaskets. If the engine RPM increases when you spray a particular area, it indicates a vacuum leak in that location. Caution: This method is flammable, so take necessary precautions and avoid spraying near hot engine components.

5. OBD-II Scanner: Use an OBD-II scanner to check for any error codes related to the engine's air-fuel mixture. Codes like P0171 (System Too Lean) or P0172 (System Too Rich) can indicate a vacuum leak.

Tools Needed:

• Mechanic's gloves
• Flashlight
• OBD-II scanner
• Smoke machine (optional)
• Carburetor cleaner or starting fluid (optional)
• Vacuum hose assortment

Step-by-Step Fix

Once you’ve identified the vacuum leak, you can proceed with the repair. Here’s a step-by-step guide:

1. Gather Parts and Tools: Collect the necessary replacement vacuum hoses, clamps, and tools. Make sure to have the correct size and type of hoses for your 2020 Subaru WRX.

2. Disconnect Battery: Disconnect the negative terminal of the battery to prevent any electrical shorts during the repair process.

3. Locate the Leak: Refer to your diagnosis to pinpoint the exact location of the vacuum leak.

4. Remove Old Hose/Component: Carefully disconnect the old vacuum hose or component that is leaking. Use pliers or hose clamps pliers to remove any clamps.

5. Install New Hose/Component: Install the new vacuum hose or component, ensuring a secure fit. Tighten any clamps to prevent future leaks.

6. Double-Check Connections: Double-check all connections to make sure they are properly seated and secured.

7. Reconnect Battery: Reconnect the negative terminal of the battery.

8. Start Engine and Test: Start the engine and listen for any hissing sounds. Use carburetor cleaner or starting fluid (with caution) to check for any remaining leaks.

9. Clear Error Codes: Use your OBD-II scanner to clear any error codes that may have been triggered by the vacuum leak.

10. Test Drive: Take your 2020 Subaru WRX for a test drive to ensure that the issue has been resolved and that the engine is running smoothly.

Technotitclan, a WRX enthusiast, mentioned during their shortblock saga: "Sticking on the new foam seals along the edges off the covers took longer than everything else. Once the cam gears were in i had it timed and covers on in 15 min." (source). This illustrates that even seemingly simple tasks can be time-consuming, emphasizing the need for patience and attention to detail.

Parts and Tools Needed

• Vacuum Hose Assortment: Various sizes and lengths to replace damaged hoses. (e.g., Gates 27093)
• Hose Clamps: To secure vacuum hoses (e.g., Murray 8M)
• OBD-II Scanner: For reading and clearing diagnostic codes. (e.g., Autel MaxiCOM MK808)
• Smoke Machine: For detecting vacuum leaks (optional, but highly recommended). (e.g., Launch Smoke Leak Detector)
• Mechanic's Gloves: To protect your hands.
• Pliers: For removing and installing hose clamps.
• Screwdrivers: For tightening screws and clamps.

Some owners also add aftermarket parts to help with boost. As Technotitclan noted, "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. Always ensure proper fitment when installing aftermarket components.

Real Owner Costs

The cost of fixing a vacuum leak can vary depending on the location of the leak, the parts needed, and whether you choose to do it yourself or take it to a mechanic.

DIY Repair:

• Vacuum hoses: $10 - $30
• Hose clamps: $5 - $10
• Carburetor cleaner: $5 - $10
• Total: $20 - $50

Professional Repair:

• Diagnosis: $75 - $150
• Parts: $20 - $50
• Labor: $100 - $300
• Total: $195 - $500

Keep in mind that these are just estimates. The actual cost may vary depending on your location and the specific repair shop. As one owner, Purple-Story3090, discovered, major engine work can be incredibly expensive: "This is crazy high right? I originally wanted to go with this shop so I told them before I dropped the car off that it had rod knock and I wanted to go with forged internals." (source. Regular maintenance and addressing small issues early can help prevent more costly repairs down the road.

Prevention

Preventing turbo overheating in your 2020 Subaru WRX involves regular maintenance and paying attention to your car's performance. Here are some tips:

• Regularly Inspect Vacuum Hoses: Check the condition of your vacuum hoses every 6 months and replace any that are cracked, worn, or brittle.
• Maintain Proper Engine Cooling: Ensure that your cooling system is functioning properly. Check the coolant level regularly and flush the system as recommended in your owner's manual.
• Use High-Quality Fuel: Using high-quality fuel can help prevent engine knocking and pre-ignition, which can contribute to turbo overheating.
• Avoid Excessive Idling: Excessive idling can cause the engine to overheat, especially in hot weather.
• Monitor Engine Performance: Pay attention to any changes in engine performance, such as decreased power, unusual noises, or increased heat.

What Owners Say

Real experiences from SUBARU owners:

Owner Experiences

"This is crazy high right? I originally wanted to go with this shop so I told them before I dropped the car off that it had rod knock and I wanted to go with forged internals." — Purple-Story3090 (source)

"I decided to just vacuum most of the particles but is there a chance it could ruin the turbo if some small particles are inside the blade? This could be best seen in image 2." — Subie69696969 (source)

"I got a new BL turbo and noticed it had a bunch of these little particles from the packaging. I decided to just vacuum most of the particles but is there a chance it could ruin the turbo if some small particles are inside the blade?" — Subie69696969 (source)

Lessons Learned

⚠️ "Have them revise the price to be just a shortblock and turbo, you'll be around $15k and still get "forged internals" Edit: this will also depend on what turbo you want." — leftfootbraker (source)

Real Repair Costs

"It only is so fucking crazy high cause you are going a the full sha-bang. You could get a built shortblock for $5k and then repair existing damage to the OEM long block, buy a new turbo and ta-da you just cut off $9k from the quote putting you right in the budgeted area." — leftfootbraker (source)

"I originally wanted to go with this shop so I told them before I dropped the car off that it had rod knock and I wanted to go with forged internals. They asked me my budget, I told them $15k and they said we would be able to work with that budget, I get this invoice and I’m like ok no, let’s just do stock." — Purple-Story3090 (source)

"An IAG 550 short block and a lower end turbo would only be like $5-6k in parts. Also, just asking, you said "you actually wanted just the built short block using the existing bottom end from your car" Did you mean top end?" — SuperStubbs9 (source)

FAQ

Q: How long does it take to fix a vacuum leak?

A: The time it takes to fix a vacuum leak can vary depending on the location and severity of the leak. A simple hose replacement may take less than an hour, while a more complex repair could take several hours.

Q: Can I drive with a vacuum leak?

A: While you can technically drive with a vacuum leak, it's not recommended. A vacuum leak can cause your engine to run lean, which can lead to overheating and potential damage. It's best to address the issue as soon as possible.

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

A: While not exclusive to the 2020 Subaru WRX, vacuum leaks are a relatively common issue on turbocharged vehicles. The increased pressure and heat can accelerate the wear and tear on vacuum hoses and connections.

Q: DIY vs mechanic - what's recommended?

A: If you're comfortable working on cars and have some experience, you may be able to diagnose and fix a vacuum leak yourself. However, if you're not confident in your abilities, it's best to take your car to a qualified mechanic. As Purple-Story3090 experienced with a more complex engine issue, professional help may be necessary: "I originally wanted to go with this shop so I told them before I dropped the car off that it had rod knock and I wanted to go with forged internals." (source.