2010 Toyota Prius: engine knocking or ticking

Filed Sep 13, 2026 · Brakes · CA

Subject: Vehicle Safety Defect Complaint / Request for Investigation Review Vehicle: 2010 Toyota Prius VIN: [XXX] Component: Electronic Brake Booster / Pressure Accumulator Assembly Dear Administrator, I am writing to formally report a critical safety defect in my 2010 Toyota Prius regarding the electronic brake booster and accumulator pump assembly. This component exhibits classic failure symptoms—specifically a distinct puffing, ticking, and pressure-loss noise directly from the brake pedal mechanism—which points to internal nitrogen or hydraulic pressure leakage. This component was previously the subject of Toyota’s Customer Support Program / Safety Recall (Campaign ZJB / D0H) due to fatigue cracking in the internal accumulator bladder. However, Toyota's arbitrary cutoff timelines have left me completely unprotected, even though the underlying engineering defect remains identical and poses an active, catastrophic threat to public safety. The real-world implications of this failure are severe: •Daily Risk to Life: I am a self-employed small-business owner who relies on this vehicle daily to travel between clients across the greater [XXX] area. Because of this failing component, I experience profound fear every single time I drive that I will completely lose my brakes in heavy traffic. •Financial Barrier to Remedy: Authorized Toyota dealerships have quoted me several thousand dollars for the repair. Due to a 40% drop in my business income amid the soaring cost of living in [XXX], I cannot afford this repair, nor can I afford a rental car or alternative transportation. My car is my literal lifeline, forcing me to drive a vehicle with a compromised, safety-critical braking system. •Unfair Expiration of Safety Remedies: My vehicle was serviced by authorized Toyota dealerships twice during the active primary campaign window (on XXX at 36,675 miles, on 08/30/2019 at 41,238 miles), where recall status checks were routinely requested INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(

Filed Aug 21, 2020 · Electrical · 77,000 miles · CA · fire

Tl* the contact owned a 2010 toyota prius. The contact stated that after driving his vehicle for seven hours, the contact had parked the vehicle in his friend's driveway. Thirty minutes later, the contact's friend received a knock on the door from a fireman asking him who owned a prius. After the contact identified himself as the owner, the fireman informed him that his vehicle was involved in a fire. A fire report and police report were filed at the scene. No injuries were reported as result of the fire. The vehicle was destroyed by the fire and was towed to an independent junk yard. The contact notified the manufacturer of the failure and the contact was given a case number. The contact was also informed that an investigation would be launched regarding the matter. The contact had sent photos and email correspondences to the manufacturer; however, he never heard back from the manufacturer. Upon investigation, the contact discovered a recall on his vehicle under the federal safety agency campaign number: 18v684000 (hybrid propulsion system) which he linked to his failure. The contact had not spoken to a dealer about the failure. The failure mileage was 77,000.

Filed Oct 21, 2019 · Brakes · 110,000 miles · MD · crash

I was making a left turn, creeping into a parking space, in a residential area. When I pressed the brake pedal to stop the car, the car accelerated instead. I then slammed on the brakes and the car accelerated again, causing me to go over the curb, over the sidewalk and knock down a fence and shed. I turned the vehicle off, some kind bystanders took the debris off the car so that I could get out. I then called police and the property owner, as well as my insurance company. I am honestly scared to drive the car again, as I do not want this unintended acceleration to happen again. I will be notifying toyota, and the repair shop working on my car has already been informed.

Filed Feb 10, 2018 · Engine, Fuel system · 125,000 miles · NC

At about 125k miles, my prius nearly ran out of oil between services, and I religiously service my vehicle. I burned 1 to 2 quarts between services since. At 272,408 miles, I just paid $5751.59 for a complete engine rebuild... Rest of car is in great shape. Oil consumption problems were known by the dealerships, but I was given no recourse except dealing with it. Latest issue..check engine light on, misfire on cylinders 1 and 4 (progressing to all), horrific knocking noise with sound of rushing water upon start-up. Eventually, (once the cylinders fired significantly) the engine could run satisfactorily for the remainder of the drive... Until the next start. Early on I read that toyota knew of the under-engineered motor of the 2010s, but I have not received anything announcing a recall or care to fix their engineering issue. I have my service records to validate the care I've given to my car. The date of the engine rebuild is what I will provide as to when this happened, but the oil consumption began years ago.

Filed Apr 9, 2012 · Engine · NY

During cold temperature startups the engine knocks loudly for about 7 seconds. The problem happens only during cold temperature. This has happened about four times. Went to dealer and they were not able to fix or find the cause. 2nd trip they replaced the engine mount but the problem is still there.

Filed Oct 19, 2011 · Engine · 14,000 miles · IL

Engine knocks upon starting but goes away after about 10 seconds. The vehicle doesn't do this very often and it is difficult to duplicate. Reference this youtube video for an exact replication of the problem: http://youtu.be/tcbg97ubx5s.

Filed Feb 5, 2010 · Brakes · 850 miles · WI

We purchased new 2010 prius at the end of last september in 2009. Both of us have had the experience of "losing control" of the car while braking on icy roads. My first experience happened during our first big snow fall. I was approaching the entrance ramp to an express way and had to apply the breaks when a car infront of me began to slow down and slide to the left side of the ramp. As I applied the breaks, the car began a series of quick forward jerks associated with knocking sounds. I also heard a slight change in how the engine sounded. Fortunately, I escaped a traffic accident since my prius drifted to the right before control was reestablished. It was frightening. This is the first car I have owned that has an anti lock braking system. I assumed that is why I experienced the loss of control and why it felt so uncomfortable. When I told the dealership about it, I was advised to take the car to an open area and practice using the brakes in order to get used to it. Since then, my husband has had the same experience while trying to stop the car on icy roads. He tells me that the "jerking" and the knocking sound is not part of a normal anti lock breaking system. This is why I am reporting our experience to the u.s. The federal safety agency. Thank you.

Filed Feb 4, 2010 · Brakes · 15,000 miles · SC

Tl*the contact owns a 2010 toyota prius. The contact was driving approximately between 35-40 MPH and encountered a bump in the roadway. There was pressure applied to the brake pedal, followed by no power response for a few seconds. The vehicle resumed to normal operation. In addition, there was an excessive knocking noise coming from the engine during the start up which occurred on two separate occasions. The vehicle had not been inspected for the malfunction. The failure mileage was 15,000.

Filed Feb 4, 2010 · Brakes · OK

While driving on a slick road. I tried to brake and turn into a parking lot. Brake pedal felt non responsive and car hit curb, knocking off the wheel cover and scuffing the rim.