2021 Toyota Highlander: Whining noise while driving
Common wear/failure (not a recall)
Symptoms
Owners of the 2021 Highlander report: whining noise while driving. CarComplaints.com lists 4 owner complaints, average mileage 66,100 miles.
NHTSA has 227 owner complaints for the 2021 Highlander in this area. Examples:
- NHTSA complaint ODI #11770086 (filed 10/09/2026): “The contact owns a 2021 toyota highlander. the contact stated that while driving at an undisclosed speed, there was a loud high-pitched whining sound coming from the vehicle. the contact stated that the vehicle hesitated while accelerating and the transmission…”
- NHTSA complaint ODI #11769405 (filed 10/06/2026): “Noticed a whine noise slowly progressing over a couple of weeks. researched the sound and took it for diagnostic eval. with holman toyota in mt. laurel, nj on 10/3/2026. as suspected, the transmission is failing. mechanic documented via video the fluid sample…”
Likely causes
Sources do not establish a single root cause; diagnosis is needed. Owner-reported fixes are listed below.
Fix, in plain English
Most common owner-reported solutions on CarComplaints.com: new transmission (3 reports). Check for open recalls and extended warranty coverage with a dealer before paying out of pocket.
DIY difficulty: Pro
Diagnosis needs a scan tool; repair or replacement needs a lift, transmission jack and the manufacturer's fluid fill/relearn procedure. (Our assessment.)
Cost
No sourced cost range: get a written quote after diagnosis.
Typical parts (search links, no affiliate codes)
AutoZone · O'Reilly · Advance · RockAuto
Sources
- CarComplaints.com: Whining noise while driving (2021 Highlander)
- NHTSA complaints API, 2021 Highlander
Page last updated .