Toyota Prius knocking problems

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 Mar 15, 2026 · Engine · PA

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)

Filed Mar 2, 2026 · Engine · GA

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.

Filed Mar 19, 2025 · Brakes · NJ

My break actuator goes off every 12 seconds continuously. There is no warning sign in the dash board. Brought the vehicle to the Toyota dealership and had it checked out. The dealership says there is no problems according to their analysis. But the actuator continuously goes off every 12 seconds and the dealership said this was "normal" and charged me the service fee. I am seriously concerned because I drive this car with my child and I am reading that this is a bad sign and that the breaks might fail at any time. Since the dashboard doesn't give me a warning sign and the dealership says there's no problems based on their diagnostics, even if everyone can hear the actuator go off ever 12 seconds I guess I can safely drive this vehicle...it seems like driving a ticking disaster waiting to happen.

Filed Aug 9, 2022 · Engine · 140,000 miles · CA

The contact owns a 2013 Toyota Prius. The contact stated while driving at approximately 65 MPH, she heard a rattling and knocking noise then smoke started to spread throughout the vehicle. The vehicle was towed to the dealer where the dealer stated that the piston disintegrated and caused damage to the engine. The vehicle was diagnosed and the contact was informed that the head gasket and engine needed to be replaced. The vehicle was not repaired. No warning lights were illuminated. The manufacturer was notified of the failure and the contact was informed to replace the engine. The approximate failure mileage was 140,000.

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 Dec 24, 2019 · Brakes, Engine · 21,000 miles · NH

From day #1 these issues were present on 2013 prius five: lka suddenly stops car over minor car movements ahead,major knocking sounds from engine on cold starts, brake pedal hits floor and suddenly locks up! I now have 20k and hardly drive it now trips skid icon?, bluetooth is erratic, cruise control shuts off or won't turn on when its wet out, drizzles or rains! Is my toyota my mother warning me not to drive in bumper to bumper traffic, avoid rain or snow, not to use electronics or listen to music while driving and if I use the tech in this 36k prius five its causing me to drive like a 90 yr old with bad eyes and even poorer judgement! It's a wonder why some people hate prius drivers..! The 12v battery dies every few days so I must keep it plugged in. I even wrap my fob in foil at home and keep it as far from car as possible to not wake up the car if I walk by a window close to its parked to avoid power drain. Toyota tells dealer everything is okay? ....in what world would anyone pay to have a car like this and tell customers its okay?? I have to drive and other people's lives are in danger! My son is now getting ready to drive and I can't imagine him fighting the controls that toyota built in to keep him safe! I used to manage a porsche dealership and raced on many tracks and can drive fairly well and don't like to complain but after my recent issue and research found a lot of common problems with others so I chimed in..

Filed Nov 6, 2019 · Brakes · FL

I just found out yesterday after a visit to a toyota dealership service center that the ABS brake actuator on my 2009 prius has failed and needs to be replaced. I was quoted at $1750 for the part and $605 for the labor, pre-tax. I did some additional research on this issue and found that there was a warranty enhancement program ' zg1 specifically for this part and issue. (https://toyotatalk.com/wp-content/uploads/2018/09/t-cp-zg1-a110-d-1.pdf) in late 2018 I first reported clicking and knocking in my brakes, and last time I went for service (before today) I reported it to the service representative. The program was for 10 years after the date of original sale, which ended in april 2019. Because the bad part lasted 6 months longer I don't feel that it is right for me to have to pay for the faulty workmanship in the vehicle from the factory when it first drove off the lot. The issue that I reported back then are the preliminary signs of the actuator going bad (https://priuschat.com/threads/brake-actuator-warranty-extension-from-toyota.168243/) had this issue been caught I would have been in the warranty enhancement window and would not be in the hole I am now where I am sitting at having to spend half the value of my car to fix it. My issue is that I do not feel that it is right for me to be on the hook for this part since toyota has itself confirmed the part was faulty when it was put on my vehicle and was honoring replacements. It seems a little unfair that toyota wouldn't acknowledge that my part is faulty and replace it as soon as it came to light. What can I do to get some relief for this matter because I need my car to be functional to get to work and pay my bills!

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 15, 2019 · Engine, Transmission · 1 miles · CA

Went in to have the spark plugs and 2 coils(cylinders 1 & 2) started shaking, knocking and smoking at the time I picked it up. Check engine light is on and hasn't gone off. The mechanic I take the vehicle to says it is a problem with this model car, trying to determine this, since he stated it is now my head gasket that needs replacing.