What causes excessive oil consumption in the 2020 Toyota Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes

medium

Difficulty

medium

Severity

3 min read

576 words

Problem Statement

Learn about the symptoms, causes, and diagnostic steps for excessive oil consumption in the 2020 Toyota Highlander. Find out how to address this issue effectively.

Affected Component

engine

Symptoms

•Frequent need to add oil between oil changes
•Blue smoke from the exhaust, especially during acceleration
•Puddles or spots under the vehicle where oil may have leaked
•Possible illumination of Check Engine Light due to oil-related issues or engine misfire

Diagnostic Steps

1
Check Oil Level using the dipstick
2
Inspect for Leaks underneath the vehicle
3
Smoke Test to observe for blue smoke from the exhaust
4
Compression Test on each cylinder
5
Leak-Down Test to identify air escaping
6
PCV Function Test for proper operation
7
Oil Quality Check to confirm oil type meets specifications

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•Oil Dipstick
•Ratcheting Wrench Set
•Compression Tester
•Leak-Down Tester
•Oil Catch Pan
•Torque Wrench
•PCV Valve Tool

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Diagnostic Steps

1
Check Oil Level using the dipstick
2
Inspect for Leaks underneath the vehicle
3
Smoke Test to observe for blue smoke from the exhaust
4
Compression Test on each cylinder
5
Leak-Down Test to identify air escaping
6
PCV Function Test for proper operation
7
Oil Quality Check to confirm oil type meets specifications

Solution

Excessive Oil Consumption in the 2020 Toyota Highlander

Potential Causes

Worn Piston Rings: Allowing oil to enter the combustion chamber.
Valve Seal Failure: Causing oil to leak into the cylinders.
Turbocharger Issues: If equipped, a failing turbo may introduce oil into the intake.
PCV System Malfunction: A faulty Positive Crankcase Ventilation (PCV) system can lead to excessive oil consumption.
Oil Leaks: External leaks from gaskets or seals.
Oil Quality: Using incorrect oil viscosity or low-quality oil can lead to increased consumption.

Tools Required

Oil Dipstick: For checking oil levels.
Ratcheting Wrench Set: For disassembly.
Compression Tester: For checking cylinder compression.
Leak-Down Tester: For diagnosing internal engine issues.
Oil Catch Pan: For catching oil during inspections.
Torque Wrench: For reassembly of components.
PCV Valve Tool: If needed for removal and inspection.

Repair Instructions

Step 1: Check and Top Off Oil

Open the hood and locate the dipstick.
Remove the dipstick, clean it, reinsert, and pull it out again to check the oil level.
If low, add oil as necessary, ensuring it meets the manufacturer's specifications.

Step 2: Inspect for External Leaks

Place the vehicle on a level surface and inspect the engine bay and undercarriage.
Look for wet spots, especially around the oil filter, oil pan, and gaskets.
If leaks are found, replace the affected seals or gaskets.

Step 3: Perform Compression and Leak-Down Tests

Remove the spark plugs to access the cylinders.
Attach the compression tester to the first cylinder and crank the engine.
Note the readings; repeat for each cylinder.
For the leak-down test, attach the tool and pressurize each cylinder, listening for air escaping from the intake or exhaust.

Step 4: Inspect the PCV System

Locate the PCV valve (typically near the valve cover).
Remove it and check for blockages or damage.
If defective, replace the PCV valve and ensure hoses are clear.

Step 5: Evaluate Oil Quality

If the oil appears dirty or has an incorrect viscosity, change the oil and filter, using the correct type (SAE 0W-20).

Conclusion

After performing these diagnostic steps and repairs, monitor the oil consumption over the next few weeks. If excessive consumption persists despite these measures, further investigation into engine internals or professional diagnosis may be required.