2018 Toyota Sienna: whining or grinding noise

Filed Nov 6, 2026 · Transmission · AZ

Since 2018–2019, our 2018 Toyota Sienna has had recurring drivability and suspected transmission problems, including stalling, failure to engage or accelerate when the accelerator is pressed, rough idle, hesitation, and harsh shifting. We reported these concerns to Toyota and filed an the federal safety agency complaint during our first year of ownership. The problems have continued intermittently for years and now include transmission whining, slipping, delayed gear engagement, irregular shifting, and reduced power. Unexpected stalling or failure to accelerate creates a safety risk when entering traffic, crossing intersections, or avoiding hazards. On October 19, 2026, AAA inspected the vehicle following a four-wheel-drive malfunction warning. Its October 20 invoice documents UA80F eight-speed transmission-related fault codes P0740-7E, P2713-7F, and P2756-7F and notes possible sticking valve-body solenoids. Toyota's own Technical Service Bulletin T-SB-0160-18 (issued December 17, 2018; revised May 11, 2021), titled "Transaxle Whine Noise, Harsh Shift, MIL ON, or Reduced Power," applies to certain 2017–2018 Siennas and lists these exact three codes (formatted P07407E, P27137F, P27567F). Toyota's Customer Support Program ZJC, Policy Bulletin POL19-04 (2019), also acknowledges transmission whine, harsh shifting, reduced power, and warning lights in certain UA80-equipped vehicles and describes a possible assembly defect involving a washer tab and loosening internal nut. An authorized Toyota dealer evaluated the vehicle October 24–30, 2026, after receiving AAA's findings but reported it could not reproduce a warning light and that the VIN/transmission serial number were outside program limits. No transmission repair was performed. The vehicle remains unrepaired. Please investigate whether this longstanding safety-related failure affects vehicles beyond Toyota's stated production cutoff.

Filed Sep 22, 2026 · Transmission · MI

Whining noise when accelerating, transmission shop reported discovery of damage to transmission upon removal and inspection of transmission.

Filed Sep 17, 2026 · Transmission · MI

Transmission whining above 20mph. Toyota customer care program [XXX] states my vehicle falls within timeframe but dealer and corporate will not honor repairs INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 14, 2026 · Transmission · FL

Vehicle: 2018 Toyota Sienna XLE AWD, VIN [XXX], approximately 112,000 miles. Component: Power Train / Automatic Transmission (UA80F 8-speed). The vehicle has developed a pronounced whining noise from the transmission that rises with road speed, accompanied by harsh/rough shifting. A Toyota dealer inspected the vehicle and diagnosed a failing transmission requiring replacement. The symptoms and diagnostic trouble codes match those described in Toyota TSB T-SB-0160-18 ("Transaxle Whine Noise, Harsh Shift, MIL ON, or Reduced Power") for the UA80 8-speed transmission. This is the same failure mode Toyota acknowledged in Customer Support Program ZJC, which attributes the defect to a washer/locking tab that was not sufficiently bent during assembly, allowing an internal nut to loosen and causing progressive internal damage. However, this vehicle's transaxle serial number falls outside the range covered by ZJC, so Toyota has not provided coverage despite the identical defect and symptoms. This represents a safety concern. Based on documented failures of this transmission across the UA80 platform, the condition can progress to loss of power, limp mode, or sudden loss of forward propulsion while driving — including at highway speed and without further warning — creating a risk of a crash or of being stranded in traffic. The vehicle has been maintained through authorized Toyota service. I am requesting that the federal safety agency investigate whether the UA80/UA80F transmission defect warrants a broader safety defect determination and recall, given the volume of similar complaints across affected model years INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Feb 23, 2026 · Transmission · WI

My 2018 Sienna had developed a whining noise when accelerating. After taking it in to the mechanic, they advised the transmission was failing. Estimated price tag of $6500-7000 to repair. The vehicle has less than 140K miles. Looking at different issues with this make/model and year, it seems like its rather common. I bought a Toyota for its reputation of getting at least 200K if not more miles. I called both the dealer and Toyota themselves. Both said too bad, so sad - nothing they could do for me.

Filed Feb 2, 2026 · Transmission · 126,000 miles · SD

The contact owns a 2018 Toyota Sienna. The contact stated that while driving 30 MPH and ascending a hill, the vehicle started making an abnormal whining sound and hesitated while accelerating. The vehicle was driven to the dealer to be diagnosed. The vehicle was diagnosed with transmission failure. The manufacturer was notified of the failure. The failure mileage was approximately 126,000.

Filed Jan 16, 2026 · Transmission · CT

Transmission has been whining. A P27137F Code appeared and the vehicle is only in 2WD mode currently. Concerned to drive vehicle due to further damaging transmission or getting stuck while on the road.

Filed Aug 4, 2025 · Transmission · WA

Transmission Whine and Hesitation. Low gear it will hesitate from stop. Know issue with this transmission. There should be a recall on all ua80 transmissions.

Filed Apr 26, 2025 · Transmission · MN

Whining sound coming from vehicle while in drive and accelerator is depressed. Confirmed by dealership that the transmission is failing and needs replacement.

Filed Apr 5, 2024 · Transmission · SD

There has been a "whining" noise or "hum" upon acceleration noticed for several months to a year, could be longer, but getting worse over time. There is also a delay when pressing on gas for the vehicle to actually accelerate. I have had many instances where I am almost hit from behind because of this delay. Obviously the person's behind me have been following me entirely too closely, but nonetheless, scary. This is our primary vehicle for our family, which carries 4 precious boys. I am aware of the CSP already in place for this issue but have been told that my specific vehicle does not qualify for the customer protection program. That seems very odd given the amount of vehicle's listed as "affected"(83,700) sienna's and 66,500 highlanders. You cannot tell me that there are not more out there like mine that are having the SAME problems but being told "not covered". I do not think anyone should have to drive a vehicle with children in it that you are unsure when your transmission is just going to go out or fear getting hit from behind because of the delay in acceleration. Please please do something about this in order to hold toyota accountable!