784 of the
15,583 complaints filed about the Toyota Prius
are about the engine —
5% of everything owners reported.
The worst model year for it is 2010.
The contact owns a 2018 Toyota Prius. The contact stated that while having a routine oil change, the contact was made aware that there was no coolant in the coolant reservoir. No warning lights were illuminated. The contact was constantly adding coolant to the coolant reservoir; however, the following day the coolant reservoir was empty. The failure had occurred on several different occasions. The vehicle was taken back to the residence. The vehicle was not diagnosed or repaired. The contact researched and was made aware of TSB Number: 013519; however, the VIN was not included. The manufacturer was notified of the failure. The failure mileage was approximately 89,100.
NHTSA complaint #11757394 — an unverified report by a vehicle owner.
Pulling out of a parking stall, when put vehicle in drive, the engine revved up and accelerated - vehicle crashed, the brakes did not work- there was skid marks. Floor mats are factory OEM were installed properly. I did not hit the accelerator and I am in good health and mind. I have driving for over 30 years, never had and accident nor a ticket! - A county officer was at the seen and left me with vehicle that had to be towed away. The Vehicle is a total loss. I have insurance but felt that this incident need to be reported, There is no safety recalls and the vehicle was always property maintained
NHTSA complaint #11750516 — an unverified report by a vehicle owner.
Unknown. There were a multitude of codes that appeared on the diagnostics causing problems with engine. The temperature, brake, tire sensor lights are all on. The cruise control is not working. White smoke emitting from tail pipe and engine. Main engine coolant leaking. Car overheating rapidly.
NHTSA complaint #11748670 — an unverified report by a vehicle owner.
The contact owns a 2018 Toyota Prius. The contact stated that while driving at an undisclosed speed, the engine constantly overheated. An unidentified warning light was flashing on the instrument panel. An independent mechanic inspected the vehicle and became aware that the coolant reservoir was empty. One month later, the same failure reoccurred. A second independent mechanic inspected the vehicle, and the coolant reservoir was empty. The vehicle was taken to a dealer. The dealer diagnosed the vehicle with a coolant leak into the head gasket. The dealer advisor referenced a customer satisfaction program as the cause of the failure; however, the vehicle was over the mileage limit for the program. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 188,000.
NHTSA complaint #11746813 — an unverified report by a vehicle owner.
The catalytic converter heat exchanger failed internally, causing coolant to leak into the exhaust system. Symptoms included white smoke from exhaust and coolant loss with no visible ground leak. This is a documented factory defect per Toyota Technical Service Bulletin T-SB-0135-19 affecting 2016-2019 Prius models. Toyota has denied warranty coverage despite the vehicle was originally bought & spent its entire prior operational life registered in New York, a state covered under Toyota's full 15-year/150,000-mile emissions warranty. Defect was confirmed by an authorized Toyota dealership, in PA. Vehicle had approximately 83,104 miles at time of diagnosis. Manufacturer denied coverage and is forcing the customer (me) to pay a huge amount for this very well known & defective case. MOST IMPORTANTLY ITS dangerous and unsafe for all the cars our there too, since it is very well known that at a certain point this will happen, but despite TOYOTA never sent a RECALL. Due to this, engine light goes on & off, refrigerant is flammable and leaks in the exhaust pipe happens with this specific case, which ultimately could catch on fire, while the vehicle is moving or stalling. Lots of white smoke comes out of the car that directly impact the environmental aspects, and above all, people owning such vehicle, will be running into this issue, which will 100% put the safety of owner and anyone close in proximity to their vehicle at RISK. PLEASE ADD RECALL WITHOUT CAP for ALL SUCH TOYATA PRIUS due to flammable refrigerant leak inside the car engine components, and proven via strong white smoke coming out of exhaust that has the potentially to put the entire car on fire, specifically.
NHTSA complaint #11738755 — an unverified report by a vehicle owner.
Water pump failed after replacement in 2013 with 30k miles, car had only 93k miles when failed again in 2016. The potentiometer part failed, there is corrosion in the part. Was in freeway when it failed. I have reported this to different representatives. I was charged more 1.5k for a replacement of a faulty part that should last more than 50k miles.
NHTSA complaint #11737450 — an unverified report by a vehicle owner.
the cylinder head gasket blew because of the poor design of the intake manifold and the EGR system. There are updated parts to fix this issue, but there was no recall. This poor design led to the vehicle having "the Death Knock." It started doing this knock on my trip driving my daughter to college. The engine could have seized in traffic on the way to [XXX] from [XXX] . No warning lights came on telling me there was an issue. The vehicle is being taken apart now to see if my connecting rods were bent from the coolant entering the combustion chamber. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11724395 — an unverified report by a vehicle owner.
Head gasket failure. No check, engine, light or warning. My car was very well maintained regularly. After research, I found this to be a very common problem. Yes it is available for inspection. Upon request. The problem was confirmed by chemical test, ignition vapors going into engine coolant. Other symptoms were misfiring on cylinder two and cylinder four. Severe engine knocking.
NHTSA complaint #11721338 — an unverified report by a vehicle owner.
I was driving my car at over 70 mph on a highway, no check engine, no issues, just had oil changed when check hybrid system alert came on with check engine light. I started to change lanes to get to shoulder when my car just died, completely. It died in the middle of the highway merging with another major road, so I was stuck between 2 lanes of 70mph traffic on either side. The time to react to the sudden warning to my car dying was less than 2 minutes. I quickly called 911 to ask for help and was told someone had already reported my breakdown as well because my car had died in a horribly dangerous area. I was very lucky that a state trooper came quickly and blocked off my car until it could be towed for repair. I was told that I need a new Hybrid Battery. The fact that I had no signs of failure before complete shut down makes for a very dangerous driving situation and makes me second guess ever buying a Prius again.
NHTSA complaint #11711067 — an unverified report by a vehicle owner.
Crack in the Engine. I had been following the recommended Maintenance schedule, but I suddenly had issues where the engine would stall/stutter on activation (switching from electric to motor operation). The check engine light came on, and I immediately took it to the dealer who replaced the battery and spark plugs saying that was the issue. That solution did not even last a month, as I had sometimes severe shaking in the engine along with the stutter. I again brought it to the dealership who told me that the actual problem was a cracked head gasket and that the vehicle was "mechanically totaled". I was lucky that I live close to the dealership and worry what would have happened if I had to drive on it further.
NHTSA complaint #11709373 — an unverified report by a vehicle owner.
I was driving from Las Vegas to my home in Los Angeles. An alarming message began flashing on the dashboard telling me to pull over. The vehicle became hard to control. I somehow managed to get it off an exit. I was "lucky" enough to get it towed to a nearby Toyota dealership where I was told the inverter had failed and that that inverter and associated parts had to be replaced. On my 2015 Prius with only 50,000 miles on it. I SPECIFICALLY asked if there had been a recall on the electrical system of any 2015 Priuses, and they flatly said no. I also CALLED TOYOTA, and they also said there were no recalls involving the electrical system or inverters. The Barstow Toyota dealership said it would cost over $5,000 to repair AND that they wouldn't have the parts they needed for a WEEK. As it was, I had been stranded in the desert at a hotel for two days. I then had to pay $1,100 to be towed back to LA and took it to a hybrid mechanic I trust and paid them to do the work. But this cost me THOUSANDS UPON THOUSANDS. In a month where a friend of mine died (which was the reason I was driving from city to city). To have to replace this on a car with only 50,000 miles is preposterous. To NOW find out there actually IS a recall on the 2015 Prius FOR the electrical system involving the inverter is so far beyond frustrating, I don't have the correct word for it.
NHTSA complaint #11695550 — an unverified report by a vehicle owner.
The hybrid braking systems on Toyota Prius' manufactured from 2010-2015 had a serious failure of the hybrid braking system that had additional long term warranties to repair, but never recalled in order to save the money from a total recall. The Sloan Toyota dealership in Glenside knew before I purchased the 2013 Toyota Prius I purchased that a serious brake system failure was very probable with my car but failed to tell me. If they did, i would not have purchased the car. I had the 5000 mile oil change in early August and three days later after the service and a clear 25 point inspection, and the system failed. I want full reimbursement or just pay for the repair.
NHTSA complaint #11690340 — an unverified report by a vehicle owner.
My 2022 Prius LE hood latch does not work. It does not click and hood stays locked. They told me at Walmart that the hood latch is probably corroded somewhere or defective. It takes two people to open the hood. My vehicle has 54,490mi. This has happened twice now in 2 months. I have not purchased an extended warranty and this is something that should not be happening until over 100,000 miles. I've had this happen on another vehicle that was a Honda but that was because it had a lot of mileage on it. This is just a poorly manufactured defective part that Toyota decided to go cheap on and not make sure it functions past 50,000 mi. I contacted Toyota customer experience and they said that my warranty was expired and they will not be covering it. I told them that they need to make an exception because if I need to change my oil I need access to the engine. I should not be having to deal with this at such a young age of a vehicle.
NHTSA complaint #11678882 — an unverified report by a vehicle owner.
My name is [XXX] ,i am filing this report on behalf of My daughter [XXX] the driver of the vehicle that involved with the unintended acceleration on the 2009 Toyota Prius .On a good clear morning on [XXX] . My daughter drove the 2009 Toyota Prius to work- when she enter to the parking lot at the speed round 5 mile/hour . Just when she was making a left turn on to the entrance gate with her left foot on the brake pedal . On a sudden the vehicle RPM unintended rev up too high and the vehicle had an unintended accelerating to move forward aggressively causing lose control of the steering . Also she could not brake even though her left foot was on the brake pedal and pressing hard to try to stop the vehicle . . This dangerous incident causing her Prius to bumped into the electrical gate panel control box . The accident caused some damages to her Prius and to the entrance gate control box though no body was hurt . But it got us through the terrible experience because it could kill some one for sure . My daughter been driving this commute car daily in the past 5 years and she has the skill of 20 year driving with good record . This Prius of her still have all OEM equipments with no add- on parts-,no modifying part on any systems what so ever- and NO extra floor mat cause we been warned before about the possible of unintended acceleration causing by aftermarket floor mat to any vehicles. . We feel unsafe after the mystery accelerating problem on Toyota Vehicle that could take people lives . So the mystery unintended accelerating on car is REAL . I am currently checked and find out her Prius has 2 incomplete recalls (un-notice to us ) but none of them related to the unintended acceleration problem . We would like the NHTSA to take this problem seriously to save people life . I will included photos of this incidents and willing to provide all information if needed to address this problem, again to save lives . INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 5
NHTSA complaint #11670935 — an unverified report by a vehicle owner.
ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CATALYTIC CONVERTOR
Odometer Fraud. The contact purchased a 2011 Toyota Prius. The contact stated that while attempting to register the vehicle, it was discovered that there was a mileage discrepancy. The vehicle was a dealer sale. At the time of purchase, the mileage was 145,000 and at the time of registration, it was discovered that the mileage was 227,000. The contact stated that while driving at 60 MPH, the check engine warning light illuminated. The contact took the vehicle to Auto Zone and was informed that the catalytic converter had failed and needed to be replaced. The contact was informed that it was not a new failure and that there was a possibility that the dealer may have removed the check engine light prior to the sale.
NHTSA complaint #11670893 — an unverified report by a vehicle owner.
Pulled out of the driveway drove about a 100 ft heard large clunking sound front end dropped down as if there was a flat tire pulled off the highway drove through the grass 100 ft back to my home the car started smoking from the engine compartment and burst into flames. Tried to extinguish with fire extinguishers and water hose while calling 911. Fire Department extinguished the fire. Car is a complete loss. There was an oil leak trail from where the car first drop down through the grass. The car did not have a previous oil leak. The car had 300,000 miles on it. No one was injured.
NHTSA complaint #11669902 — an unverified report by a vehicle owner.
The contact owns a 2019 Toyota Prius. The contact stated there was a coolant leak and the coolant level was low. There was no indication of coolant on the ground. The check engine and engine HOT warning lights were illuminated. The contact stated that the failure was related to TSB: 0135-19. The vehicle was taken to the local dealer where it was diagnosed that there was a coolant leak in the front exhaust pipe heat exchanger. The parts to repair the vehicle were on backorder. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was approximately 95,000.
NHTSA complaint #11667430 — an unverified report by a vehicle owner.
Exhaust heat-exchanger coolant pipe (part of the hybrid cooling loop) on my 2019 Toyota Prius is the system that failed. Safety risk: complete loss of coolant can cause sudden engine overheating and possible power reduction or shutdown while the vehicle is moving. I transport two young children daily; an unexpected stall on a highway or during an intersection turn would put all occupants and surrounding traffic at risk. AutoNation Toyota Mall of Georgia (dealer) inspected the car on 22-May-2025, confirmed the leak, and advised the vehicle is unsafe to drive until the pipe is replaced. Repair estimate is $2,249 parts & labor to replace the front exhaust pipe that is on back order, no ETA. Toyota Corporate (Brand Engagement, Case # 250522002498) is aware; they escalated the file to their Parts Department because the replacement pipe is back-ordered with no estimated arrival date. No other agencies or insurers have inspected the vehicle. Two days before the dealer visit, the warning symbol began flashing briefly at breaking then for longer intervals while driving. On the morning of 22-May-2025 the lamp was flashing more often and longer prompting the service appointment. Dealer found the coolant reservoir completely empty. No prior warning messages had appeared.
NHTSA complaint #11663559 — an unverified report by a vehicle owner.