Why does my 2020 Toyota Highlander make a strange noise while accelerating?

Problem Overview

If your 2020 Toyota Highlander is making a strange noise while accelerating, it could be due to several factors. Common symptoms include whining, grinding, rattling, or hissing sounds, which can indicate issues with the engine, transmission, exhaust system, or other components. Let’s diagnose this issue step-by-step.

Possible Causes

• Loose or Damaged Exhaust Components: Can cause rattling or hissing sounds.
• Worn Engine or Transmission Mounts: May lead to excessive vibration and noise.
• Low Transmission Fluid: Could cause whining or grinding noises.
• Air Intake Issues: A vacuum leak can create a hissing sound.
• Accessory Drive Belt Problems: A worn or loose belt can cause a screeching or whining noise.

Repair Instructions

1. Exhaust System Repair

   • If you find leaks or loose components, use a wrench to tighten bolts or replace damaged sections of the exhaust.
   • If the muffler or pipes are damaged, consider replacing them.

2. Transmission Fluid Service

   • If fluid is low or dirty, replace the transmission fluid and filter (if applicable).
   • Steps:
     • Raise the vehicle and secure it on jack stands.
     • Remove the transmission pan (if applicable) and drain the fluid.
     • Replace the filter and reinstall the pan with a new gasket.
     • Refill with manufacturer-recommended transmission fluid using a funnel.

3. Engine Mount Replacement

   • If mounts are damaged, remove the old mounts using a socket set and replace with new ones.
   • Ensure the engine is properly supported while replacing the mounts.

4. Air Intake System Repair

   • Tighten any loose connections and replace a damaged air filter if necessary.
   • Inspect and replace vacuum hoses that are cracked or damaged.

5. Accessory Drive Belt Replacement

   • Inspect the belt for wear or damage.
   • If damaged, remove the old belt by loosening the tensioner and installing a new belt.

Conclusion

After following these diagnostic steps and performing necessary repairs, take your Highlander for a test drive to see if the noise persists. If the issue continues or if you are unable to identify and resolve the cause, it may be advisable to consult a professional technician for further diagnosis.