Toyota Highlander knocking problems

Filed Nov 5, 2026 · Brakes · WA

Subject: Sudden Unintended Braking and Loss of Vehicle Control – 2008 Toyota Highlander V6 AWD I am reporting a serious and potentially life-threatening incident involving my 2008 Toyota Highlander V6 AWD. Shortly before this incident, I had all four tires replaced at Les Schwab. While driving approximately at highway speeds, with my foot on the accelerator and absolutely no pressure on the brake pedal, I suddenly heard a knocking sound and felt the vehicle jerking violently. It felt similar to ABS activation, although I do not know what system was responsible. I stopped and inspected everything finding nothing wrong so proceeded to drive the car back home. The vehicle then suddenly and forcefully applied the brakes without any input from me. The rear wheels appeared to lock, causing the tires to skid. The back end of the vehicle fishtailed and began attempting to spin around. I struggled to maintain control. There were three children riding in the vehicle with me. All four occupants were placed in immediate danger. After stopping, I shifted into Park and then back into Drive. The brakes released, and the vehicle began moving normally again. However, I subsequently noticed a continuous metallic grinding noise. No ABS, traction control, or other warning lights illuminated. I am requesting an investigation into the cause of this sudden unintended braking, rear-wheel lockup, and loss of vehicle control. This incident could easily have resulted in a fatal collision. Three children were passengers in the vehicle when it unexpectedly applied its own brakes at approximately 45 mph.

Filed Apr 16, 2026 · Transmission · IL

I am an owner of a 2021 Highlander XLE AWD (bought new). In October of 2024 around 34000 miles the transmission started to make a whining noise and seemed to be surging/bucking , hesitation and hunting for gears. Toyota determined it fit the criteria of a TSB to have the transmission replaced. The dealership had my car for two months and then eventually replaced the transmission with a remanufactured unit. This “new” unit still has the issues of surging/bucking , hesitation and hunting for gears. I fear that this “new” transmission is in the process of failing again with less than 10k on it. Of course I will be out of warranty when it does and I’ll be on the hook for a $10000 repair. I’m appalled that Toyota has not done a true fix for this issue and has not even put an extended warranty on it either. I purchased this vehicle from Toyota on good faith that it would last and be reliable. 34k one transmission died and I’m sure this one will follow suite. Ultimately UA80 transmission is ticking time bomb and Toyota needs to be held accountable for this.

Filed Sep 24, 2025 · Transmission · NC

Noticed 2021 Toyota highlander start whining around 85000 miles. Did some research on the sound and found that Toyota UA80F transmissions have all had the same issue and issued a tsb to their dealerships but not people who purchased the car. Warranty runs out and now you are on the hook for an 10k transmission replacement or risk your car breaking down at any point on the road. Car was inspected today by Toyota to receive the quote to fix at 10400 with no discussion of possible remedies for their defective transmissions. The exact quote would be "that's not our problem, you have to take it up with Toyota office, bud". So now we have a ticking time bomb on the road with the only remedy to pay 10400 to replace a defected transmission that was covered in other recalls by the same company.

Filed Sep 11, 2025 · Electrical, Engine · IN

Formal Complaint to the federal safety agency – Summary I am submitting this formal complaint regarding repeated mechanical and electrical failures involving my 2017 Toyota Highlander, purchased as a Toyota Gold-Certified vehicle with an extended Platinum Warranty. Despite strictly following Toyota’s maintenance guidelines and using only certified dealerships for all services, the vehicle has become inoperable multiple times, requiring five separate tows and resulting in repair costs exceeding $10,000. In June 2025, a Toyota dealership replaced the engine after diagnosing a warped head due to water pump failure. Following this, the vehicle began experiencing repeated charging system failures and electrical malfunctions. Multiple components—including the alternator, battery, and sensors—were replaced at another Toyota dealership based on ongoing issues, but the problems persisted. On September 2, 2025, a Toyota technician identified a missing ground wire nut as the likely root cause of these electrical failures. He confirmed the issue originated during the engine installation and that the unsecured ground caused system malfunctions. After repairs, the vehicle was again returned with a loud engine knocking noise, later traced to an improperly secured component from a prior repair. These events have raised significant concerns for the safety of myself and my family. Improper installation of major components and misdiagnosis by certified service providers have led to hazardous driving conditions, unexpected vehicle shutdowns, and unnecessary costs. I am requesting that the federal safety agency investigate this matter for potential safety defects related to improper engine installation, grounding failures, and faulty electrical diagnosis by certified Toyota service centers. Documentation, invoices, and repair records are available upon request. Thank you for your attention to this critical safety issue.

Filed Aug 27, 2025 · Fuel system · UT

Today (8/26/2025) my wife experienced the engine light kicked on and that the AWD system needed to be checked. After fueling up it made knocking noises and difficulty starting, and took two times to start up. Ran an OBD scan and this is what it says, which is related to fuel pump low pressure. P117B - Fuel Pressure Sensor Circuit Range/Performance Severity - High Description - Indicates a problem with the fuel pressure sensor circuit, where the sensor's output signal is outside the expected range or performance criteria, leading to potential issues with fuel delivery or engine performance. P0174 - System Too Lean (Bank 2) Severity - High Description - Your engine is getting too much air and/or not enough fuel, this is known as a "Lean" condition. Excess oxygen is getting into your engine, which makes the combustion process less efficient. This could be caused by many different factors. Consequences of Continued Driving - Reduced power, Engine knocking, Rough idle

Filed Jul 4, 2025 · Brakes, Electrical · VA

2007 hybrid ABS brake actuator problem. The primer motor continues to run to prime the pump even when car if off. The humming noise changes when you press on the brakes to load knocking groaning noises. No dash warning signs. I bought this car used and it has always made the humming noise since I bought it. I thought this was normal for a hybrid. Sometimes brake pedal would push easily to floor, but then get tighter. I would hear the knocking grinding noise. No warning lights, had brakes checked and they are good. Thought maybe air in line. This noise and loose pedal started about 1 year ago. 6/2024 it did not happen all the time. I also have a company car, so I do not drive the toyota highlander that often. Now I cannot drive it at all. For fear that the brakes would go out. I started looking further online on information regarding this. It seems toyota and lexus rx 300 hybrids (same part model number) 44510-48060 are all doing this. I looked up recall's and nothing for ABS hybrid problems. Just last week all warning lights came on in my car brake vsc. Reading all the problems with this ABS actuator pump, this should be recalled. 6/2025 per online, it is a known problem with toyota in the hybrid models. All of these units will need to be replaced, only a matter of time. Usually toyota's run up to and overr 300k miles. I planned on keeping mine around. But it is a 2007 with 189k miles on it. I am not sure I want to invest $2000.00 on just a part for a car this old! Junk yards sell used ones for $800+. Same model number and only in time that will fail. Apparently toyota has issued a new model number 44510-48061. There is also another new model 44050-48191. The replacement part (no labor) varies in price 44510-48060 new $1200.00, 44510-48061 $1350.00, 44050-48191 $2000.00

Filed Jun 14, 2025 · Brakes, Engine · CA · crash

Yesterday, as I do a couple times a month, I went to switch parking places, putting my 2021 Toyota Highlander where my 2007 Mazda was parked, in order to drive it and keep the battery from dying. After starting both cars I first moved the Mazda to make room for the Toyota. As I was slowly steering the Toyota at (idle speed) into the now vacant parking spot, the car accelerated on it's own, prompting me to hit the brakes, but to no avail. The car jumped the curb hitting, knocking over and and damaging a large ceramic planter and small tree in my neighbor's yard. My split second reaction upon having no brakes and a run away car was to push it out of drive, which ended up putting the car into reverse, causing a harsh jolt, followed by the car accelerating again on it's own, in reverse towards another neighbor's garage. I live in a condo complex, so all of this took place within about 30 feet of forward/backward/forward motion. My second split second decision (with no brakes) to avoid smashing into the garage was throwing it back into drive, which sent it accelerating back towards the parking place again. This time I had the presence of mind to push the power button on the dash, allowing me to barely come to stop before jumping the curb again. Whole thing lasted about 15 seconds. I had an appointment to attend, so after a brief conversation explaining to my (now outside) neighbor what happened, I left in the older car. Returning later in the day I found damage to the front of my Toyota and wonder if my transmission is damaged as well. I'm reimbursing my neighbor today. I've not attempted to drive the Toyota since, and am seeking your advice on how best to proceed, whether I should initiate contact with Toyota regarding this incident, or is that something you should initiate? Please advise. Thank you.

Filed May 19, 2025 · Electrical, Engine · CA

We live on a farm so the fact there is rodents is no surprise. However strangest thing is the knock sensor harness has been chewed completely off two times in last two months.. when this happens it causes power loss. With the extra shielding the wire has tells me it gives off a low frequency that would irritate most animals and me at this point since the part is never available. If it actually gives off a frequency, it is absolutely unnecessary and a complete nuisance.

Filed Aug 19, 2024 · Transmission · 70,000 miles · CT · 2 injuries

The contact owns a 2017 Toyota Highlander. The contact stated that the vehicle was parked but still running in a driveway on an incline. After exiting the vehicle, there were abnormal beeping and ticking noises detected, and the vehicle began to roll down the street. The contact and daughter were pinned between the door and the vehicle. The contact's daughter sustained injuries to her chin and teeth. The driver has lumps and bruises on her leg and back pain, but medical attention was not provided. The rear wheels were on the curb and hit a trash can, and the vehicle stopped rolling. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 70,000.

Filed Jul 12, 2024 · Transmission · PA

Transmission Failed at 65,000. Yes, inspection available upon request. Safety is when my family with little children are in the car, and erratic shifting takes place while traveling at high rates of speed. Car has not broken down, but was told by dealer that it could "run for ever or break down tomorrow" Issue for me is that it is VERY apparent through multiple resources that Toyota clearly is aware of this issue. Recalled in 2017, and 2018.....but looks like most is happening with the 2019 with no accountability on their part. Power train warranty expires at 60,000 miles....yet 75% of reported issues are in between $60,000-$70,000 with Toyota offering ZERO assistance or taking any responsibility or action. No warnings on the dash, no lights. Either loud noise, high rev RPM, or sudden erratic shifting. Just Toyota....saying "yeah we know about it, but still not helping with it, not extending the warranty, and just leaving you with a $8,000-$10,000 bill or continue with a ticking time bomb. Negligence is a safety issue. A big one.