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Why does my 2020 Toyota Highlander emit a loud noise when accelerating? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/Why does my 2020 Toyota Highlander emit a loud noise when accelerating?

Why does my 2020 Toyota Highlander emit a loud noise when accelerating?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
3 min read
600 words

Problem Statement

Learn how to diagnose and repair loud noise issues during acceleration in a 2020 Toyota Highlander, including symptoms, potential causes, and step-by-step repair instructions.

Affected Component
exhaust system, engine mounts, transmission, tires, wheels

Symptoms

  • •Loud noise when accelerating, which may vary in intensity.
  • •Noise may be a rumble, growl, or whine, depending on the underlying issue.
  • •Noise may change with engine RPM or vehicle speed.
  • •Potential vibration felt in the vehicle.

Diagnostic Steps

  1. 1
  2. 2
  3. 3

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

  • •Flashlight
  • •mechanic's stethoscope (optional)
  • •socket set
  • •reciprocating saw
  • •hydraulic lift or jack stands
  • •OBD-II scanner

Additional Information

Affected Component
exhaust system, engine mounts, transmission, tires, wheels
Difficulty
medium
Severity
medium
Tools Required
6 items

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Back to Generation
Potential Causes
  1. Exhaust Leak
  2. Worn or Damaged Engine Mounts
  3. Transmission Issues
  4. Tire or Wheel Problems
  5. Intake System Issues

Step 1: Visual Inspection

Tools Required: Flashlight, mechanic's stethoscope (optional)

  1. Check Exhaust System:

    • Inspect the exhaust pipes, muffler, and catalytic converter for signs of rust, holes, or damage.
    • Look for any loose connections or hanging parts.

  2. Inspect Engine and Transmission Mounts:

    • Visually examine mounts for cracks, tears, or any sign of dislocation.

  3. Check Tires and Wheels:

    • Look for uneven wear, bulges, or foreign objects lodged in the tread.
    • Ensure wheel lugs are properly tightened.

Step 2: Test Drive

Tools Required: None

  1. Take the vehicle for a test drive to replicate the noise.
  2. Note when the noise occurs (e.g., at specific RPMs, speeds, or when shifting).
  3. Decide if the noise is engine-related, transmission-related, or possibly a wheel issue.

Step 3: Isolate the Noise

Tools Required: Mechanic's stethoscope (optional)

  1. While the vehicle is stationary, have an assistant accelerate the engine slightly.
  2. Use the mechanic's stethoscope to listen near the exhaust manifold, transmission, and undercarriage to localize the noise.
Repair Instructions

Repairing Exhaust Leak

  1. Locate the Leak: From your inspection, if a leak is found, note its location.
  2. Remove Damaged Sections:
    • Use a socket set to remove any bolts securing the exhaust pipe or muffler.
    • Cut out damaged sections if necessary using a reciprocating saw.
  3. Install New Parts:
    • Replace with OEM or quality aftermarket parts.
    • Use exhaust clamps to secure connections.
  4. Test for Leaks: Start the engine and listen for noises or use soapy water on joints to check for bubbles.

Replacing Engine or Transmission Mounts

  1. Lift Vehicle: Use a hydraulic lift or jack stands to elevate the vehicle safely.
  2. Remove the Old Mounts:
    • Use a socket and ratchet to remove bolts securing the mounts.
    • Support the engine or transmission with a jack if needed.
  3. Install New Mounts:
    • Place new mounts and hand-tighten bolts.
    • Lower the engine/transmission and fully tighten all bolts to manufacturer specifications.
  4. Test Drive: After replacing, take the vehicle for a test drive to ensure noise has been resolved.

Addressing Transmission Issues

  1. Check Transmission Fluid:
    • Inspect the fluid level and condition. Low or dirty fluid can cause noise.
  2. Transmission Service:
    • If fluid is low, top it off with the correct ATF. If dirty, consider a fluid change.
  3. Diagnostic Scan:
    • Use an OBD-II scanner to check for any transmission-related error codes.
  4. Professional Assessment:
    • If the issue persists, consider consulting a transmission specialist.

Resolving Tire or Wheel Problems

  1. Inspect Tires:
    • If uneven wear is found, rotate tires or replace as necessary.
  2. Check Wheel Bearings:
    • Jack the vehicle and spin the wheels to listen for grinding or roughness.
    • Replace bearings if noise is detected.
Conclusion

After performing the above diagnostic steps and repairs, monitor the vehicle for any recurrence of the noise. If the problem persists and you are unable to diagnose or repair the issue, it may be best to consult a qualified technician for further analysis.