2018 Toyota Sienna: engine and transmission complaints
HIGH COMPLAINT SIGNAL
47%
30 of 64 relevant owner complaints are about the engine, transmission or fuel system
47% of relevant owner complaints filed with NHTSA on the 2018 Toyota Sienna are about the engine, transmission or fuel system. That is a model-level pattern, not bad luck.
Worse than 58% of the 1,230 model years we track (2010–2023).
Excludes 6 airbag, lighting and seat-belt recall complaints that would otherwise mask the signal (unadjusted: 43%).
The percentage is each model year's drivetrain complaint share. No elevated signal describes the model year, not any one car; a well-kept example of a flagged model can still be the right buy, and any of these still needs an inspection.
What owners reported
POWER TRAIN07/14/2026
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…
POWER TRAIN06/21/2026
Since owning my 2018 Toyota Sienna, I have experienced hesitation and erratic shifting with my transmission. I have the UA80E transmission which upon research others are experiencing issues with as well. It appears Toyota is not fully acknowledging the problem. The problem is a safety issue as sometimes when you go to …
POWER TRAIN02/23/2026
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 commo…
Three of 30 drivetrain complaints. The full report shows more, with quotes about the engine in the car you are looking at first.
Recall campaigns on this model year (7)
FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain 2018-2019 4Runner, 2019-2020 Avalon, 2019 Corolla Hatchback, 2017-2019 Highlander, 2018-2020 Camry,…
FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
Toyota Motor Engineering & Manufacturing (Toyota) recalled certain 2018-2019 4Runner, Highlander, Camry, Land Cruiser, Sequoia, Sienna, Tacoma and Tundra, and Lexus RC 30…
STEERING
Braun Corporation (Braun) is recalling certain modified 2017-2020 Toyota Sienna vehicles. The steering shaft extensions may have been improperly manufactured, possibly c…
This does not say whether a particular car has an open, unrepaired recall. That depends on the VIN.
Before you buy a 2018 Toyota Sienna
Ask the seller whether the transmission has ever been repaired or replaced, and whether the car has shown shuddering, slipping, delayed or harsh shifts, or a whine at speed.
Drive it from a cold start and long enough to warm up. Many transmission faults hide once the car is warm.
Get an independent pre-purchase inspection from a mechanic you choose, and tell them to focus on the transmission.
7 recall campaigns on this model year. Whether a specific car still has one open depends on the VIN; the report checks that.
Ask for service records. A transmission already replaced under warranty is a different car from one that was not.
Have the VIN?Paste it and get the full report for that car. First report free, then a 30-day pass covers a whole car search.
Experimental model-level information. This is not a vehicle inspection, vehicle-history
report, financial advice or purchase recommendation. It describes patterns across a model year, not the condition
of any individual vehicle.
