Toyota Prius misfire problems

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 Dec 20, 2025 · Engine, Fuel system · AZ

misfire code along with rough starts/light load. T-SB-0116-15

Filed Dec 14, 2020 · Engine · 136,000 miles · TX

When idling there is a loud rattle and multiple random misfires in the engine. Appears to be a head gasket leak problem from reading forums. I have been to multiple repair shops they cannot determine the problem.

Filed Oct 27, 2020 · Engine · 153,000 miles · CA

Upon turning the vehicle on and starting to drive, the internal combustion engine then starts and experiences about 20 seconds of misfiring to the point the car is without smooth power. This happens at random. If the car was in the wrong situation when it happened it could cause an accident. The same thing will occasionally happen when parked after waiting for the engine to start.

Filed Mar 28, 2020 · Engine · 150,999 miles · MD

2012 toyota prius ii, dealer maintained, now needs new engine due to blown head gasket. Mileage 151000. The car has run perfectly until a recent engine light came on. When it was brought into the dealership, the diagnosis was misfiring of 2 cylinders and coolant leaking into cylinders 3 and 4. There was no previous engine problems. An official complaint was filed with toyota customer service. They responded that there was no fault on their end and I should have the engine replaced at an authorized toyota dealer. A search for this trouble resulted in several other complaints of the failure of head gaskets in this year and model prius.

Filed Oct 11, 2019 · Engine · 77,000 miles · CA

Head gasket 77,000 miles with the head gasket issue the car engine was shaking when it's warming up. The car log showed misfires in 1st and 4th cylinders.

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 Jan 29, 2018 · Engine · 91,984 miles · CA

Tl* the contact owns a 2010 toyota prius. The contact stated that the vehicle made an abnormal pounding noise and the check engine indicator illuminated. Additionally, the contact stated that the vehicle was linked to odometer fraud. The vehicle was taken to the local dealer (toyota of hollywood, 6000 hollywood blvd, hollywood, ca 90026), but the cause of the failure could not be duplicated. The vehicle was not diagnosed or repaired. The vehicle was taken to toyota of downtown la (1901 s figueroa st, los angeles, ca 90007) where it was diagnosed that the engine was misfiring and an engine compression test was needed to repair the vehicle. The vehicle was not repaired. The manufacturer was not notified. The failure mileage was 91,984.

Filed Sep 6, 2017 · Electrical, Engine · 163,500 miles · CA

Water leaking from engine cowel getting into ignition coils which is causing engine to shudder and stop sometimes too. Seems to be a known toyota issue yet not being rectified by manufacturer. Seals seem to allow water to get into the ignition coils hence the issue. Vehicle is stationary when first observed then shuddering and misfiring occurring as vehicle is being driven also leading to loss of power as its being driven which is quite dangerous on highways.

Filed Jan 27, 2017 · Transmission · 95,000 miles · WA

My 2010 toyota prius iv has 98,731 miles on it. The engine and power train malfunctioned during a cold start so I had to take it into the toyota dealer. It had to be towed to the dealership on a flat-bed tow truck because the car transaxle/transmission was locked in the drive position, would not go into neutral, and the car engine would not start rev above an idle. When I attempted to start it the engine acted like it was misfiring very badly and rattled very badly. It sounded like the engine was not getting any oil circulation so I didn't attempt any more cold starts. I could not get the engine into neutral or any other gear so I had it towed to the dealership. When the car was at the dealership I went through my records and found a letter titled 'warranty enhancement program notification - zf3' that I had received several years previous. The document extended my primary coverage until 31 march 2017 due to a potential faulty exhaust gas recirculation (egr) valve. 'a faulty egr valve would cause the engine to rough idle/rattle from the transaxle at a cold start due to a sticking egr valve. If this occurs, the vehicle may illuminate the check engine light and set diagnostic trouble code dtc p0401. If the condition is verified the vehicle will be repaired in accordance with the applicable technical service bulletin under the terms of this warranty enhancement program.' the symptoms my car experience during cold starts begin around 92,000 miles but no 'check engine light' or 'diagnostic trouble code' ever illuminated on the instrument panel. After 92,000 miles it only happened occasionally, and always during cold starts. Normally after a few seconds of idling the rattling would go away and the engine and drivetrain would perform as it should. I took my car in for a service and told the dealership what was happening, but they could not diagnose any problem.