2017 Toyota Highlander engine problems

Filed Oct 8, 2026 · Engine, Transmission · OH

Transmission failure after whining noise, taken to Toyota multiple times with no diagnosis. Today was informed the transmission is failing by another mechanic. 193,000 miles.

Filed Aug 27, 2026 · Engine · CO

My 2017 Toyota Highlander, VIN [XXX], has just under 85,000 miles. I was notified at the dealership (Stevinson Toyota in Lakewood Colorado) who inspected the vehicle yesterday that the vehicle has developed a timing cover oil leak on the passenger side. After further research I learned this is caused by premature failure of the factory applied FIPG sealant at the timing cover’s T junction. This is well documented as a known, widespread defect in the V6 engine used across multiple Toyota and Lexus models between 2014 and 2019. This failure is not due to wear, neglect, or misuse. It is the result of a documented manufacturing flaw that requires full engine removal and carries an extremely high repair cost — a burden that should not fall on customers when the underlying cause is a defective sealant application at the time of manufacturing of the vehicle. I was quoted $5400. I am deeply concerned that Toyota has not issued a recall for this problem, despite its prevalence and the clear safety risks it presents. This leak is not merely a “durability issue.” It has legitimate and serious safety implications, including: •The potential for engine fire due to oil contacting hot components •Serpentine belt failure, which can cause sudden loss of power steering, alternator function, and vehicle control •Additional engine damage if the leak worsens •The possibility of the vehicle breaking down in unsafe or remote conditions Any of these outcomes pose a real safety hazard to drivers, passengers, and others on the road. Toyota’s decision not to address this known defect through a recall is extremely disappointing. I have reached out to Brand Engagement and was turned down by a gal named [XXX]. I then escalated the issue and was again turned down by a gal named [XXX]. I firmly believe Toyota should have issued a recall for this known issue costing consumers $5400 to repair a safety issue due to what is documented as a manufacturing defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B

Filed Aug 20, 2026 · Engine, Transmission · NH

I had been shopping, as I attempted to increase speed, my car wouldn't respond. I smelled something burning and I switched lanes because I needed a safe place to stop. I turned onto [XXX] in Pembroke (I think) and still had no forward (or backward) movement. The lower gears (D5 & D4 ) DID NOT show on the dashboard indicator. I called my husband and he came to me. Then we called AAA and had the car towed to Chichester Car Care. They couldn't fix my car. I then had it towed from Chichester Car Care to McGovern Toyota in Bow. NH. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 15, 2026 · Engine · NY · crash

bought the car in 2018 and ever since it makes a rttling noise, Toyota says it is the hybrid system engaigeing, hybrid cars are not supposed to make noise.

Filed Jun 3, 2026 · Engine · 151,000 miles · TX

The contact owns a 2017 Toyota Highlander. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer, who determined that the spark plugs needed replaced. The spark plugs were replaced by an independent mechanic, but the failure recurred. The vehicle was taken back to the independent mechanic, who retrieved diagnostic trouble codes P11F0 (Air-Fuel Ratio Imbalance) and P0305 (Misfire In Cylinder Number 5). The mechanic cleaned the fuel injectors, but the failure persisted. The contact was informed that the fuel injectors needed to be replaced. The vehicle was taken to a second dealer, Toyota of Cedar Park (5600 183A Toll Rd, Leander, TX 78641), who determined that cylinder #5 needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 151,000.

Filed Jan 15, 2026 · Engine · 95,402 miles · OR

The contact owns a 2017 Toyota Highlander. The contact stated that when the vehicle was taken to a dealer for routine maintenance, the dealer informed the contact that the rear main seal was leaking and needed to be resealed. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 95,402.

Filed Dec 23, 2025 · Engine · MN

I drive a 2017 Toyota Highlander and am having issues with the transmission. The issues and poor craftsmanship on the UA80 8-speed transmissions. Toyota offered Technical Service Bulletins T-SB-0160-18, T-SB-0008-21, and a limited Customer Support Program (CSP ZJC). But very few VINs were included and there are tons of Highlander owners with this transmission facing $10,000+ repair bills for what is supposed to be one of the most reliable cars and car brands on the planet. This is very wrong. Toyota has not stood by its customers and have not done right by owners. Toyota needs to recall the transmissions and offer a remedy at no cost to the customer. This needs to be done now. It's completely unacceptable. Thanks for what you do and for reading! Appreciate you guys very much.

Filed Nov 20, 2025 · Engine · 60,000 miles · IL

The contact owns a 2017 Toyota Highlander. The contact stated that upon taking the vehicle to an independent mechanic for service, the contact was informed that the engine was leaking due to a timing chain failure. The contact was advised that the engine needed to be taken apart to repair the vehicle. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was filed. The failure mileage was approximately 60,000.

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 Jul 14, 2025 · Electrical, Engine · MO

After getting gas, the vehicle will not start. It will crank and crank but not turn over, like it is starving for gas. Then after 10-15 minutes it will start barely and to keep it running I have to floor the accelerator. Any other time it starts just fine. There are also no codes causing a check engine light.