2020 Subaru WRX Coolant Leaking? Here's How to Fix It

How to Fix Coolant Issues

Coolant problems can be concerning for any 2020 Subaru WRX owner. These issues can range from minor annoyances to potential engine damage if left unaddressed. Many owners have shared their experiences dealing with coolant issues, and this guide aims to provide you with a comprehensive understanding of the problem, potential causes, and steps you can take to resolve it. As one owner stated, "Sounds like you have a coolant leak or maybe some air in the system, any recent work on the cooling system? I'd start simple and check the radiator/expansion tank caps for damage." — fugredditforeal (source

Symptoms

The symptoms of a coolant issue in your truck can vary, but there are some common indicators to watch out for. One of the most noticeable signs is a coolant leak. This could manifest as a visible puddle under your vehicle, often green or reddish in color. You might also notice a decrease in the coolant level in your reservoir. Keeping an eye on your fluid levels is important to catch any problems early on.

Another symptom that owners have reported is a distinct smell. This smell is often described as sweet or sickly and can be particularly noticeable after driving. A coolant smell can indicate a leak somewhere in the system, potentially near the engine or radiator. You might also notice the smell coming through the vents in the cabin.

In some cases, a coolant issue can cause the engine to sputter or run roughly. This can happen if the coolant level is low, leading to overheating and potential engine damage. Sputtering can also be a sign of air in the cooling system, which can interfere with the engine's ability to maintain a stable temperature. If you notice this happening, it’s best to investigate and act quickly.

Pay attention to your temperature gauge. If the engine runs hot, you likely have a coolant issue to resolve. Don't ignore this, as it will only lead to more expensive repairs in the long run. If your coolant levels are low, or you have a leak, it is best to not drive it until you can get it looked at.

Most Likely Cause

Based on owner reports, the most likely cause of coolant issues in your truck is an intake leak. While not directly related to coolant, an intake leak can create conditions where coolant is lost or burned, leading to the observed symptoms. An intake leak can disrupt the air-fuel mixture, causing the engine to run less efficiently and potentially overheat.

An intake leak can affect the engine's ability to regulate temperature properly. The engine could start burning the coolant, as one owner described: "No recent work however coolant definitely leaked or burnt (most likely) because it was half between full and fill and my green coolant was now red (forgot to mention the most important part)." — Maximum_Stick804 (source. This loss of coolant will lead to the symptoms described above.

It's important to note that other factors can also contribute to coolant issues. Issues such as a damaged radiator cap, a faulty thermostat, or a failing water pump could also lead to similar problems. However, focusing on the most frequently reported cause (intake leak) is a good starting point for troubleshooting.

How to Diagnose

Diagnosing a coolant issue requires a systematic approach. Start by visually inspecting the cooling system for any obvious leaks. Look for puddles of coolant under the vehicle and check the radiator, hoses, and water pump for any signs of damage or corrosion. Check hose clamps to see if they are tight and if hoses have bulges or cracks.

Next, check the coolant level in the reservoir and radiator. If the level is low, top it off and monitor it closely over the next few days. This will help you determine if the coolant loss is ongoing. A pressure tester can also be used to check for leaks in the system. This tool pressurizes the cooling system, making it easier to spot any leaks.

To check for an intake leak, you can use a smoke machine or a carburetor cleaner. Spray the carburetor cleaner around the intake manifold while the engine is running. If the engine RPMs change, this indicates a leak in that area. Alternatively, a smoke machine can be used to introduce smoke into the intake system, making it easier to spot any leaks.

Tools needed for diagnosis:

• Flashlight
• Coolant pressure tester
• Smoke machine or carburetor cleaner
• Gloves
• Safety glasses

Step-by-Step Fix

Addressing a coolant issue can be a straightforward process if you follow these steps.

1. Inspect the Cooling System: Start by visually inspecting the radiator, hoses, and water pump for any signs of leaks or damage.

2. Check Coolant Level: Verify that the coolant level is within the recommended range. Top off if needed. As one owner shared: "Did another check this morning checking belts, see if i missed anything last night, and top up coolant just in case since it was low." — Spiritual-Review-160 (source

3. Pressure Test the System: Use a coolant pressure tester to pressurize the system and check for leaks. Apply pressure and watch for a drop in the gauge.

4. Identify the Leak Source: Once you have identified the source of the leak, assess the severity of the issue.

5. Repair or Replace Leaking Components: If the leak is coming from a hose, replace it with a new one. Ensure that you use the correct type of hose for coolant applications.

6. Address Intake Leaks: If you suspect an intake leak, tighten the intake manifold bolts to the manufacturer's specified torque.

7. Flush the Cooling System: After making the necessary repairs, flush the cooling system to remove any contaminants or debris. Use a coolant flush product and follow the instructions on the bottle.

8. Refill with Coolant: Fill the cooling system with the correct type of coolant for your vehicle. Make sure to mix the coolant with distilled water in the proper ratio.

9. Bleed the System: Bleed the cooling system to remove any air pockets. This can be done by opening the bleeder valve (if equipped) or by squeezing the radiator hoses while the engine is running.

10. Monitor Coolant Levels: After completing the repairs, monitor the coolant level closely for the next few days to ensure that there are no further leaks.

Parts and Tools Needed

To address a coolant issue effectively, you'll need the right parts and tools. Here's a list of the essentials:

• Coolant: The correct type of coolant for your vehicle. (Refer to your owner's manual for the specific type and ratio of coolant to distilled water.)
• Hoses: Replacement hoses for any damaged or leaking lines.
• Hose Clamps: New hose clamps to secure the hoses.
• Radiator Cap: A new radiator cap if the old one is damaged or worn.
• Coolant Flush: A coolant flush product to clean the system.
• Distilled Water: Distilled water for mixing with the coolant.
• Coolant Pressure Tester: For diagnosing leaks in the system.
• Wrenches and Sockets: Various wrenches and sockets for removing and installing components.
• Screwdrivers: Screwdrivers for tightening hose clamps and other fasteners.
• Funnel: A funnel for adding coolant to the system.
• Drain Pan: A drain pan for catching coolant during the flush.
• Gloves and Safety Glasses: To protect your hands and eyes.

Real Owner Costs

The cost of fixing a coolant issue can vary depending on the severity of the problem and whether you choose to DIY or take it to a shop.

DIY:

• Coolant Flush: $10-$20
• New Hoses: $20-$50 per hose
• Radiator Cap: $10-$20
• Coolant: $20-$30 per gallon
• Tools (if needed): $50-$100
• Total DIY Cost: $110-$220

Professional Repair:

• Diagnostic Fee: $80-$150
• Coolant Flush: $80-$150
• Hose Replacement: $100-$200 per hose (including labor)
• Radiator Cap Replacement: $50-$100 (including labor)
• Intake Leak Repair: $200-$500 (depending on the complexity)
• Total Professional Repair Cost: $510-$1100+

Keep in mind these costs are estimates and can vary depending on your location and the specific shop. The complexity of diagnosing and fixing the intake leak may be significant if you are not familiar with the engine.

Prevention

Preventing coolant issues in your vehicle involves regular maintenance and careful monitoring. Here are some tips to help you keep your cooling system in good condition:

• Regularly Check Coolant Levels: Check the coolant level in the reservoir regularly and top off as needed. Do this at least once a month.
• Inspect Hoses and Clamps: Inspect the hoses and clamps for any signs of damage or wear. Replace any damaged components immediately.
• Flush the Cooling System: Flush the cooling system every 30,000 to 50,000 miles to remove any contaminants or debris. As one owner mentioned: "Have you changed the coolant? My engine head gasket failed at 135k doing oil changes at 6k miles and I think the culprit was not ever changing the coolant." — jman_7 (source
• Use the Correct Coolant: Always use the correct type of coolant for your vehicle, as recommended by the manufacturer.
• Avoid Overheating: Avoid overheating the engine, as this can damage the cooling system. If you notice the temperature gauge rising, pull over and let the engine cool down.
• Regular Maintenance: Follow the manufacturer's recommended maintenance schedule for the cooling system.
• Monitor Engine Temperature: Pay attention to your engine temperature while driving and address any anomalies promptly. As one owner noted: "DAM- dynamic advanced multiplier, should show 1.000 all the time, any less it's pulling timing. (Stage 0 will start at 0.688) Intake temp / coolant temp - intake temp in the summer, I don't go wot if intake Temps are like 30 degrees over ambient." — StreetKhorne (source

What Owners Say

Real experiences from SUBARU owners:

Success Stories

"No recent work however coolant definitely leaked or burnt (most likely) because it was half between full and fill and my green coolant was now red (forgot to mention the most important part) so I’m thinking headgasket, but it has no new codes and drives perfectly normally even on redline pulls, the smell is gone now aswell I only smelt it once" — Maximum_Stick804 (source)

Owner Experiences

"Sounds like you have a coolant leak or maybe some air in the system, any recent work on the cooling system? I'd start simple and check the radiator/expansion tank caps for damage." — fugredditforeal (source)

"Have you changed the coolant? My engine head gasket failed at 135k doing oil changes at 6k miles and I think the culprit was not ever changing the coolant." — jman_7 (source)

"I think Cobb says anything up to -4 is "normal" but I rarely get over -2.81 Fine knock learn - knock readings in the RPM band based on historical data." — StreetKhorne (source)

Pro Tips from Owners

💡 "As long as your engine gets up to temperature regularly, you should not have to adjust your oil change interval for this. Also, you should be changing your oil often anyways!" — Serious-Education-51 (source)

💡 "Some cans run a coolant curcuit to keep them warm. As long as your engine gets up to temperature regularly, you should not have to adjust your oil change interval for this." — Serious-Education-51 (source)

FAQ

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

A: The time it takes to fix a coolant leak can vary depending on the source and severity of the leak. A simple hose replacement might take an hour or two, while addressing an intake leak or water pump issue could take several hours or even a full day.

Q: Can I drive with a coolant leak?

A: Driving with a coolant leak is not recommended, as it can lead to overheating and potential engine damage. If the leak is minor and you can keep the coolant level topped off, you might be able to drive a short distance to a repair shop. However, it's best to have the issue addressed as soon as possible.

Q: Is this a common issue on this vehicle?

A: While coolant leaks can occur on any vehicle, they are not necessarily more common on the 2020 Subaru WRX than on other models. However, as the vehicle ages, components like hoses and seals can deteriorate, increasing the risk of leaks.

Q: DIY vs mechanic - what's recommended?

A: Whether to DIY or take your truck to a mechanic depends on your mechanical skills and the complexity of the repair. Simple tasks like replacing a hose or radiator cap can often be done at home with basic tools. However, more complex repairs like addressing an intake leak or replacing a water pump are best left to a professional mechanic. If you're unsure about your ability to perform the repair safely and correctly, it's always best to seek professional help.