553 of the
10,828 complaints filed about the Toyota Sienna
are about the engine —
5% of everything owners reported.
The worst model year for it is 2000.
I am submitting this complaint to request that the National Highway Traffic Safety Administration (NHTSA) document and evaluate what may be a broader defect affecting certain Toyota Sienna vehicles and determine whether it presents a potential safety-related defect trend. My 2015 Toyota Sienna was diagnosed by an authorized Toyota dealership with an external rear-bank head gasket leak. A head gasket is a critical engine component, and failure can result in coolant loss, engine overheating, reduced engine performance, stalling, or complete vehicle disablement. These conditions may create a safety risk, particularly if they occur while driving in traffic or at highway speeds. An authorized Toyota dealership confirmed the diagnosis and submitted a goodwill assistance request to Toyota. The dealership noted my history as a repeat Toyota customer and recommended that assistance be provided. Toyota denied the goodwill request based on the vehicle's age and mileage. I subsequently appealed through Toyota's customer relations process, and the denial was upheld. I understand that NHTSA does not resolve individual warranty or customer-assistance disputes. My purpose in submitting this complaint is to request that NHTSA determine whether similar reports exist involving premature head gasket failures in this model year or related vehicles and, if warranted, evaluate whether a broader defect trend exists that could present a safety concern. Potential safety consequences include engine overheating, loss of power, stalling, and unexpected vehicle disablement. The vehicle has been maintained in accordance with manufacturer recommendations and has not experienced any overheating event that would reasonably explain a premature head gasket failure. Thank you for your consideration and for documenting this complaint as part of NHTSA's review of potential vehicle safety issues. Respectfully, Vehicle Owner
NHTSA complaint #11751053 — an unverified report by a vehicle owner.
Sluggish start when hot - fuel pump leak into engine when hot, causing starter issues, wears out starter, causes other stress on engine. Common issue in Toyota Siennas. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11748426 — an unverified report by a vehicle owner.
The contact owns a 2007 Toyota Sienna. While the contact’s wife was pulling into the parking space, the transmission shifter was shifted into park(P), and the vehicle suddenly rolled forward approximately four feet. The parking brake was activated, preventing the vehicle from crashing into a parked vehicle. The vehicle was towed to the residence. While examining the vehicle, the contact determined that the shifter cable bushing had failed and needed to be replaced. The vehicle was not yet repaired. The manufacturer and local dealer were notified of the failure. Additionally, previously while driving there was smoke coming from the engine compartment and the vehicle stalled. The vehicle was towed to the local mechanic who diagnosed the vehicle and determined that the oil cooler line had failed causing engine oil to spill from the engine. The rubber oil cooler line was replaced with an updated improved oil cooler line, and the vehicle was repaired. The failure mileage was 170,000.
NHTSA complaint #11746381 — an unverified report by a vehicle owner.
The vehicle is a 2020 Toyota Sienna. While driving, the engine suddenly shut off without warning, creating a dangerous situation and loss of power. This occurred while transporting children, increasing the safety risk. A mechanic inspected the vehicle and diagnosed a failure of the low-pressure fuel pump. The problem appears intermittently — sometimes the vehicle runs normally, and other times it stalls or loses power. The check engine light has turned on and off. This issue matches the known defect related to the Denso fuel pump recall affecting many Toyota vehicles from similar model years. However, my VIN is not included in the recall. This is a serious safety concern because the engine can shut off unexpectedly while driving, which could lead to an accident. I believe this vehicle may have the same defective component as those included in the recall, even though it is not currently listed. The issue has been confirmed by an independent mechanic and the vehicle is available for inspection if needed.
NHTSA complaint #11733827 — an unverified report by a vehicle owner.
The contact owned a 2008 Toyota Sienna. The contact stated that while he was away, the fire department called to notify him that his vehicle had caught fire while parked in the driveway. The contact's neighbor was alerted to the fire by the vehicle's alarm system and called the fire department. The fire department extinguished the fire but was unable to determine the cause of the fire. A fire department report was filed. The fire destroyed the interior of the vehicle. The insurance company was made aware of the failure, but had not yet deemed the vehicle totaled. The vehicle remained in the driveway. The contact stated that the vehicle was an equipped BraunAbility handicap wheelchair ramp van. The contact also stated that prior to the fire, the vehicle had no failure and no warning light was illuminated. In addition, The fire wall of the engine performed as designed and protected the engine, although the interior of the vehicle was severely damaged as a result of the fire. The manufacturer was not made aware of the failure. The failure mileage was approximately 107,000.
NHTSA complaint #11727073 — an unverified report by a vehicle owner.
i am having repeated issue with Toyota sienna engine 1. Engine oil leaks through timing chain cover 2. Engine coolant leak Engine oil leak keep repating even I fixed earlier and leaks again due poor engine design same issue fixed on Nov/22/20 - 59k
NHTSA complaint #11716185 — an unverified report by a vehicle owner.
Subject: Safety Defect Complaint – 2017 Toyota Sienna (VIN: [XXX] ) Dear NHTSA Safety Division, I am submitting a safety complaint regarding my 2017 Toyota Sienna, VIN [XXX] . In June 2023, while traveling on I-81 South in Virginia with my family of seven, the van stalled suddenly and emitted white smoke from under the hood, then the engine completely failed. The vehicle had only 111,000 miles. The repair would have cost $15,000, and I had to sell the van in 2024 for $4,000, suffering significant financial loss. Toyota informed me no recall applies to my VIN, although many 2017 Siennas experienced fuel pump failures causing stalling. As a person with disability and serious health issues, this incident caused extreme stress, hardship, and risk to my family. I request that NHTSA investigate this potential safety defect to determine whether other 2017 Siennas are affected. Sincerely, Your Name Phone Number Address INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11700382 — an unverified report by a vehicle owner.
ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM)
The contact's mother owns a 2004 Toyota Sienna. While the contact's mother was driving at an undisclosed speed, several unknown warning lights illuminated. The contact stated that the warning lights illuminated on and off for days and months. The vehicle was taken to an independent mechanic where DTC: P2241 was retrieved. The vehicle was not repaired. The contact was advised to take the vehicle to the dealer. The vehicle was taken to the dealer where the failure code was confirmed. The contact was informed that the oxygen sensors needed to be replaced. In addition, the contact was informed that a TSB for the ECM software update needed to be performed. The contact stated that the vehicle was not repaired because the ECM software update was performed, and the ECM software update damaged the ECM. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 150,132.
NHTSA complaint #11699794 — an unverified report by a vehicle owner.
Coolant leaking from rear of the engine through the head gasket. Vehicle struggles to accelerate beyond 55mph or 80kmph. A quick search on the internet shows that this is a frequent occurrence in this 3.5L V6 engine from Toyota model years 2011 through 2017.
NHTSA complaint #11691968 — an unverified report by a vehicle owner.
The contact owns a 2017 Toyota Sienna. The contact stated that occasionally while driving approximately 35 MPH, the vehicle lost automotive power before jolting forward. There was an unknown warning light illuminated. In addition, the contact stated that the failure had progressed over time. The vehicle was taken to a local independent mechanic; however, the cause of the failure was unknown. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 69,000.
NHTSA complaint #11691232 — an unverified report by a vehicle owner.
The contact owns a 2014 Toyota Sienna. The contact stated that while driving 70 MPH, there was an audible alarm coming from the vehicle, alerting the contact that the door was ajar. The passenger’s side slide door opened independently while the vehicle was in motion. The vehicle was modified to accommodate a ramp for the contact's two wheel-bound children. The contact pulled over to the side of the road and closed the sliding door. The contact's husband tied the door to prevent it from opening independently again. The check engine warning light was intermittently illuminated. The vehicle was taken to the dealer, where it was inspected. The contact was informed that two latches had corroded and needed to be replaced. The vehicle was not repaired. Upon further investigation, the contact related the failure to NHTSA Campaign Number: 16V858000 (STRUCTURE). However, the VIN was not included. The manufacturer was not made aware of the failure. The failure mileage was approximately 99,500.
NHTSA complaint #11685365 — an unverified report by a vehicle owner.
My engine caught on fire. We had seconds to get out prior to it engulfing in flames. Fire department had to extinguish. Not sure what caused it. The entire vehicle caught on fire. There was an engine light warning I had the vehicle repaired but the warning light was not cleared
NHTSA complaint #11660309 — an unverified report by a vehicle owner.
Pressure Control Soleneoid "A" Prformance stuck oof -P0746. Second opionin: Valve bddy Assembly clutch kits inside transmission. Toyota of Dallas refuse to provide service. I had done Tranmission service done by them . Need to get it fix van with new transmission installed and correct any other recall of 2025 to be fix.
NHTSA complaint #11644315 — an unverified report by a vehicle owner.
The contact owns a 2018 Toyota Sienna. The contact stated while driving at an undisclosed speed, the vehicle jerked and lost motive power. In addition, the contact stated that on several occasions the vehicle shut off independently. The vehicle was taken to the dealer; however, the failure could not be duplicated. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. In addition, the contact stated that the vehicle was taken to the dealer several times due to the failure. The contact stated that the failure began in 2019 but had become a persistent failure. The contact stated the vehicle was repaired under of an unknown recall and the fuel pump was replaced in 2020; however, the failure reoccurred. The manufacturer was not made aware of the failure. The failure mileage was unknown.
NHTSA complaint #11613601 — an unverified report by a vehicle owner.
I was driving around 30 MPH when the vehicle suddenly turned off. The engine stopped running, all instrumentation turned off, no power steering and no brakes. The car became uncontrollable until it coasted to a stop.
NHTSA complaint #11604798 — an unverified report by a vehicle owner.
The head gasket that was repaired failed and the radiator system also failed. Im not sure if these issues are dealer related or manufacture related as i spoke to the previous owner and they stated they had the vehicle serviced at a manufacturer prior to doing a trade in with the dealer
NHTSA complaint #11585798 — an unverified report by a vehicle owner.