2018 Toyota Sienna Problems

What owners report

Owners of the 2018 Sienna most often describe transmission complaints: a whine that rises with speed, hesitation from a stop, and delayed or harsh downshifts, sometimes diagnosed by dealers as a failing transmission. A second theme is drivability around acceleration and fuel delivery, including hesitation, stalling, and no-start episodes; many of those complaints were filed alongside the low-pressure fuel pump recall. The sampled complaints are spread across the model year and include a large share of very low-mileage reports (under 10,000 miles), plus a cluster of recall-notification complaints about parts not yet being available.

1. 1
   Transmission and drivetrain

   Transmission whine and hesitation

   • 15 complaints (21%)
   • median 126,000 mi at 5.5 yrs old (3 state mileage, few)
   • filed 2019–2026

   Owners describe a whining or humming noise from the drivetrain that rises with road speed, often together with hesitation when pulling away from a stop and delayed or harsh downshifts under throttle. Several complaints state a dealer diagnosed a failing transmission needing replacement, and some note the vehicle was outside a Toyota customer support program for this transmission. A few mention warning messages or stored codes appearing alongside the noise. Reported from as low as a few thousand miles up to roughly 126,000 miles, with several reports between 35,000 and 60,000 miles and a later group above 100,000 miles.

   2 related service bulletins

   What to check: Drive the van at steady speeds and listen for a whine that tracks with speed, and feel for hesitation or harsh shifts on light throttle. Ask whether any transmission repairs, reprogramming, or customer support program work has been done.

   2 excerpts from owner complaints in NHTSA records

   “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.”

   NHTSA complaint #11719964, filed 2026-02

   “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.”

   NHTSA complaint #11711540, filed 2026-01
2. 2
   Fuel system

   Hesitation, stalling and no-start

   • 11 complaints (15%)
   • median 35,000 mi at 2.1 yrs old (7 state mileage, few)
   • filed 2018–2026

   Complaints describe the engine stalling or sputtering while driving, hesitation when the accelerator is pressed, and occasional no-start episodes after refueling, with the check engine light coming on. Some owners report a shop or parts store reading a fuel pump failure code and taking the van to the dealer. Many of these complaints were filed after receiving the low-pressure fuel pump recall notice, and some state the remedy parts were not yet available. Spread from very low mileage (under 2,000 miles) through 50,000-60,000 miles, often reported during or after a dealer or recall visit.

   Recall 20V682000Recall 20V0120002 related service bulletins

   What to check: Ask whether the fuel pump recall work has been completed and keep the paperwork. Note any hesitation on takeoff or long cranking before start during a test drive.

   2 excerpts from owner complaints in NHTSA records

   “The fuel line under the intake ruptured when I started my car on 2/21/23. The repair shop said they had never seen one fail like this. I do not have the parts. I was fortunate to be at home and that the engine wasn't hot when this happened so there was no fire. I had an issue starting the car ~ 1 month before that, but I don't know if the issue was fuel related. The car had been sitting for 1 week prior to that issue.”

   NHTSA complaint #11509440, filed 2023-02

   “Car stalled, sputtered and died. At first, I thought I was out of gas. After several tries, the car started and went 3 miles to gas station. After getting gas, the car wouldn’t start several times and that same day the check engine light came on. We took it to Autozone to check the code and they said it was showing fuel pump failure. Today I’m taking it in to the dealer for service. It has started and run twice since the initial episode.”

   NHTSA complaint #11474649, filed 2022-07
3. 3
   Other or unknown

   Recall notice with no remedy parts

   • 10 complaints (14%)
   • median 22,500 mi at 2.5 yrs old (6 state mileage, few)
   • filed 2020–2021

   Several complaints are not about a part failure but about the recall process: owners state they were told the repair could not be done because parts were unavailable, leaving them waiting. Some describe consequences such as being unable to renew a registration or uncertain about driving the vehicle while the notice was open. Others note a conversion or accessibility modification complicated the recall repair. Mostly filed during 2020, shortly after the fuel pump recall notices went out, with low or unreported mileage.

   Recall 20V0120001 related service bulletin

   What to check: Check the VIN against open recall campaigns and confirm with the seller or dealer that any outstanding remedy has actually been performed, not just scheduled.

   2 excerpts from owner complaints in NHTSA records

   “I am unable to pay my renewal registration fee because there is no available remedy for the recall on my vehicle yet. I am not sure what to do at the moment. The dmv told me to contact my dealer. But my dealer responded by stating that there is no remedy to fix the vehicle yet. The dealer said that I should notify the dmv so that they could investigate further and allow me to pay my dues. This current covid-19 pandemic has made it difficult for me to get in contact with the dmv.”

   NHTSA complaint #11325626, filed 2020-05, 10,000 miles

   “There is a recall notice on my van and Toyota has no solution for it as of yet and it is causing me to be unable to renew my registration online and I will now have to pay a late fee.”

   NHTSA complaint #11327691, filed 2020-06
4. 4
   Body and structure

   Sliding door and seat movement concerns

   • 8 complaints (11%)
   • median 8,700 mi at 1.2 yrs old (5 state mileage, few)
   • filed 2018–2025

   Owners report power sliding doors that close on their own or do not stop when something is in the way, and a door cable that broke and was not covered by a service bulletin. A separate group of complaints describes power third-row or rear seats operating by themselves, including while the vehicle is moving or occupied. Dealers replaced floor rail caps in one case, and the reported behavior continued. Reported across a wide range, from about 1,000 to 8,700 miles in the door and seat complaints, with the door cable failure reported without a mileage figure.

   What to check: Operate both sliding doors through several open and close cycles, test the obstruction reversal, and check that the rear power seats only move when commanded.

   2 excerpts from owner complaints in NHTSA records

   “The automatic sliding doors do not have an auto/emergency stop if something impedes their shutting. A child can get crushed if an adult is not there to stop the doors. Even though I was there it was very hard for me (an adult) to stop the doors from closing. Yes, the child was wrong for pushing the close button then reaching back in the van to retrieve something. He thought it would stop until he was done. …”

   NHTSA complaint #11130170, filed 2018-09, 8,700 miles

   “3rd row power seats are malfunctioning and are operating while vehicle is in motion. Multiple times, and on different days, the power seats have started to close while passenger is seated and buckled in the seat. Occurred today while on the highway, at highway speed while my wife was seated in the drivers side 2 seat split. The seat started to close on its own - no one touched any button and we had been driving for over an hour. The seat put pressure on her until it stopped in a partially closed position. …”

   NHTSA complaint #11181710, filed 2019-02, 24,000 miles
5. 5
   Air bags

   Airbag non-deployment in collisions

   Mentioned in 4 of 60 sampled complaints

   In several complaints owners state that front airbags did not deploy in a front-end or animal impact, while side airbags did deploy in at least one rollover. Another complaint describes trim or light parts becoming projectiles when the airbags did deploy. Complaints note the vehicles were inspected or the manufacturer was contacted, but no cause was identified in the reports. Reported in collisions at highway speeds, with vehicle mileage around 31,000 to 117,000 miles.

   What to check: Ask about any collision history and whether airbag-related work or inspection was performed after a crash; a pre-purchase inspection can check for airbag fault codes and signs of prior deployment.

   2 excerpts from owner complaints in NHTSA records

   “Takata recall (?) we purchased this van on 4/18/2019, previously the van was a rental. The next evening, going to dinner on a friday night about 9 p.m. I was on a 2 lane road in a rural area, traveling at 60 MPH and a dog walked in front of me. I had no time to react. The front end of the van was laying in the road, not drivable. Again, a front end collision and no air bag deployment! 2nd Toyota Sienna, first a 2017 and now a 2018, both rental sales, both had front end collisions and both had no air bag deployment. …”

   NHTSA complaint #11204731, filed 2019-04, 31,000 miles

   “When turning left in a busy intersection, our van was struck by another vehicle on the front passenger corner of the car. The strike occurred with my van going about 10 mph, the other car going about 45 mph. All of the airbags deployed. When the airbags deployed, the coverings on the lights came off and the small lightbulb and silver casing projected out, scratching my son's arm. Nothing in the vehicle should break or become a projectile when the airbags deploy. I am not certain on the last few questions.”

   NHTSA complaint #11419945, filed 2021-06

Buying note. Prioritize a Sienna whose transmission has been checked or serviced, and confirm the fuel pump recall remedy has actually been completed. A test drive including highway speeds, stop-and-go takeoffs, and a full cycle of the sliding doors will surface most of what owners describe.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.