Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2011 Toyota Prius owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2011 Toyota Prius. The contact stated while driving approximately 35 MPH, the contact smelled an abnormal burning odor and then heard an abnormal explosion. The contact observed black smoke coming from under the hood. The contact pulled off the road and turned the vehicle off. The contact stated no warning light was illuminated. The contact lifted the hood and saw flames coming from under the engine. The contact was able to extinguish the fire with a fire extinguisher. The contact had the vehicle towed to his residence. The contact called an independent mechanic who diagnosed the vehicle and determined that the engine needed to be replaced. The contact stated that when the engine was lifted out of the engine compartment, there was a hole in the engine block. The vehicle was repaired. The manufacturer had not been informed of the failure. …
The contact owns a 2011 Toyota Prius. The contact stated that while operating the vehicle, the check engine warning light remained illuminated, the vehicle had unexpectedly shut off. Additionally, the transmission failed to shift into the intended gear. The vehicle was towed to the local dealer who replaced the catalytic converter, but the failure persisted. The vehicle was towed back to the dealer who diagnosed that the inverter was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure, but no assistance was offered. The contact was informed that the VIN was not included in the NHTSA Campaign Number: 14V053000 (HYBRID PROPULSION SYSTEM, ELECTRICAL SYSTEM). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 117,000.
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.
The contact owns a 2011 Toyota Prius. The contact stated while driving at 60 MPH, the vehicle lost motive power and stopped in the middle of the road. There was no warning light illuminated. The vehicle failed to restart and was towed to an independent mechanic who informed the contact that they could not duplicate the failure. The dealer and the manufacturer were not notified of the failure. The vehicle was not diagnosed or repaired. The failure mileage was approximately 190,000.
one year after bought, was losing power, replacing a lot of batteries, headlights and lamps then car would lose power while driving, not start continually everyday for each day after and even started on its own. i took in a lot and they put my vin to the wrong person..someone rainsford so my service recs were not recorded. said no battery code, didnt check altenator, and even tho serv advisor said the break was squishy to him and he heard the loud buzz noise when pushing, it was not replaced. they tried to blame it on keys being in car which is how it starts and runs! not parked on hill or in bad temps and driven long trips, none of which SHOULD BE REQIRED to start a car to get to dying patients on time. we bought charger and use on both priuses daily. lost power while driving, got hurt, and josh's pt. died. nothing but headache nightmares. …
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. …
If I make a longer trip more than 10 to 15 miles the car does fine if I drive it 2 miles down the road or across the street to a different store the car tells me to check hybrid system. I had it check and code c1391 came up and that was repaired. Once repaired picked up from shop drove across the street to gas station and it told me to check hybrid system again and went into limp mode. Once I do a reset the car will start back up and drive fine as long as it's a long trip if I go on another short trip it will do it again.
In 11/2024, I started experiencing intermittent noises coming from the engine compartment of my 2011 Toyota Prius. The initial sound resembled the buzzing noise generated when first starting the vehicle. Then the noise started to persist for extended periods after the vehicle was turned off. It would oscillate between buzzing for approximately 10 seconds & remaining dormant for about 1 minute, repeating this cycle. The duration of these cycles could extend for up to 20 minutes. Concurrently, I experienced several instances where the brake pedal would abruptly become stiff & difficult to press. Notably, no warning lights were illuminated on the dashboard. …
Tl* the contact owns a 2011 Toyota Prius. The contact stated that while attempting to park in a parking space, the vehicle independently accelerated and crashed into a sign post. The contact stated that the brake pedal was depressed during the independent acceleration. There was no injuries sustained. A police report was not filed. The vehicle was repaired by the insurance company. Neither the dealer nor the manufacturer was notified of the failure. The failure mileage was 80,000.
Request help with 2011 Toyota Prius oil consumption, quality, safety, & air pollution issues: I bought the car new. Just after 100,000 miles I noticed it was using oil between oil changes. It has gotten way worse to now at 145,000 miles it used 3 qts in 2000 miles. It does not warn you that the oil level is low until you are 3.5 qts low & a messages says you have low oil pressure. This is unsafe in that the car could go dry on oil and the engine sieze up. There is a TSB on this for other Toyota vehicles, but not yet Prius. I believe Prius needs to be added to the list & I want Toyota to replace my engine or at least the piston rings. So far Toyota is not admitting to oil consumption problems with the Prius. This is also a possible emissions issue. I contacted Toyota's customer experience center in feb 2016 and they set-up case no. 1602170764 to track my complaint. …
Engine complaints in other Prius years
Frequently asked questions
How common are engine problems on the 2011 Toyota Prius?
NHTSA has 52 complaints about the engine & cooling of the 2011 Toyota Prius, 10% of the model year's 521 complaints. The component named most often is cooling system (1 mentions).
Is there a recall for 2011 Toyota Prius engine problems?
No. NHTSA lists no engine & cooling recall for the 2011 Toyota Prius, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2011 Toyota Prius engine problems start?
Half of the complaints with a recorded mileage happened before about 110,000 miles, and 19% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 2 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.