2021 Toyota 4Runner Problems: 9 Known Issues
2021 model year · 1,986+ owner reports · Updated October 2026
According to Au7o's analysis of 1,986+ owner reports, the 2021 Toyota 4Runner has 9 documented known issues. None of the listed issues is rated critical; this is not a complete reliability assessment. The most commonly reported issue is KDSS (Kinetic Dynamic Suspension System) Leaks/Corrosion with 876 owner reports. Across all issues with published estimates, repair costs range from $50 to $4,000. DIY maintenance guides at au7o.io.
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All 9 Known Issues
NHTSA Recalls5 recalls
EQUIPMENT:OTHER:LABELS
Southeast Toyota Distributors, LLC (SET) is recalling certain 2023 Toyota 4Runner vehicles. The load carrying capacity modification label states the incorrect load carrying capacity, which can result in an overloaded vehicle. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 110, "Tire Selection and Rims."
EQUIPMENT:OTHER:LABELS
Gulf States Toyota, Inc. (GST) is recalling certain Toyota 2023 GR Supra, 2024 4 Runner, Corolla, Grand Highlander, Grand Highlander Hybrid, Land Cruiser Hybrid, Tacoma, Tacoma Hybrid, 2023-2024 BZ4X, Corolla Cross Hybrid, GR Corolla, GR86, Highlander, Highlander Hybrid, Prius, Prius Prime, Sequoia Hybrid, Tundra, Tundra Hybrid, Venza Hybrid, 2023-2025 Crown, and 2025 Camry Hybrid vehicles equipped with GST accessories. The load carrying capacity modification label may display inaccurate added weight values. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 110, "Tire Selection and Rims."
EXTERIOR LIGHTING:HEADLIGHTS
Southeast Toyota Distributors, LLC (SET) is recalling certain 2022 Toyota 4Runner vehicles. The driver's side high beam may be inoperable after the installation of accessory fog lights. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."
EQUIPMENT:OTHER:LABELS
Southeast Toyota Distributors, LLC (SET) is recalling certain 2020-2022 4Runner vehicles equipped with 20-inch Black Gunner Wheels. The load carrying capacity modification labels are incorrect. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 110, "Tire Selection and Rims."
EQUIPMENT:OTHER:LABELS
Gulf States Toyota, Inc. (GST) is recalling certain 2022 4Runner, Tacoma, Highlander, and Highlander Hybrid vehicles. The load carrying capacity modification labels may not be permanent and can fade, becoming illegible. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 110, "Tire Selection and Rims."
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Frequently Asked Questions
What are the most common Toyota 4Runner problems?
According to Au7o's analysis of 1,986+ owner reports, the 2021 Toyota 4Runner has 9 documented issues. The most frequently reported are: KDSS (Kinetic Dynamic Suspension System) Leaks/Corrosion, A/C Compressor Failure, Starter Corrosion / Contact Wear Causing Intermittent No-Crank and Stalling. None are rated critical, but regular maintenance is recommended.
Is the Toyota 4Runner reliable?
The 2021 Toyota 4Runner has 9 known issues documented across 1,986+ owner reports. None of the matching records is rated critical; this is not a complete reliability assessment. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Toyota 4Runner problems?
Repair costs for known Toyota 4Runner issues range from $50 to $4,000, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2010-2023 Toyota 4Runner KDSS (Kinetic Dynamic Suspension System) Leaks/Corrosion?
The KDSS hydraulic suspension system can develop leaks at the hydraulic lines and accumulators, especially in areas with road salt. The system helps reduce body roll on-road while allowing articulation off-road. Corrosion of the KDSS lines is common in northern states. Repairs typically run $300-$4,000. Severity: medium.
What is the 2010-2022 Toyota 4Runner A/C Compressor Failure?
The A/C compressor can fail prematurely, often sending metal debris throughout the system. When the compressor fails, the entire A/C system typically needs to be flushed and the condenser, drier, and expansion valve replaced along with the compressor to prevent repeat failure. Repairs typically run $1,200-$2,500. Severity: medium.
What is the 2010-2022 Toyota 4Runner Starter Corrosion / Contact Wear Causing Intermittent No-Crank and Stalling?
The starter on 2010-2022 4Runners is prone to corrosion, and if corrosion migrates into the starter relay/solenoid contacts it can cause intermittent no-crank (a single click or nothing on key turn) and, in some cases, additional driveability gremlins. Because the starter sits lo… Repairs typically run $150-$500. Severity: medium.
What is the 2010-2024 Toyota 4Runner Front door lock actuator stops locking or unlocking (owner reports)?
Owners of fifth-generation 4Runners report a front door lock actuator failing so the door no longer locks or unlocks with the key fob or switch, sometimes on low-mileage trucks and sometimes on more than one door. Applies to: 2010-2024 Toyota 4Runner. The owner reports linked her… Severity: medium.
What is the 2003-2024 Toyota 4Runner Power rear hatch window sticks or won't go up or down (owner reports)?
Owners of fourth- and fifth-generation 4Runners report the roll-down rear hatch window moving only an inch at a time, sticking partway, or not going up at all. When the glass is not fully closed, owners also lose the rear wiper and defroster. Applies to: 2003-2024 Toyota 4Runner… Severity: medium.
What is the 2003-2024 Toyota 4Runner Harsh or abrupt automatic transmission shifts (owner reports)?
Owners report harsh shifts from the automatic transmission. On fourth-generation trucks they describe intermittent hard engagement into drive or reverse and clunking downshifts when stopping; on fifth-generation trucks, harsh 1-2 upshifts and hard downshifts when coming to a stop… Severity: medium.
What is the 2010-2023 Toyota 4Runner Steering Rack Clunk / Intermediate Shaft Noise?
A clunk or pop may be heard from the steering column area when turning the wheel, especially at low speeds or when going from left to right. The issue is typically the intermediate steering shaft or worn rack bushings. Common on vehicles driven off-road. Repairs typically run $50-$1,500. Severity: low.
What is the 2003-2024 Toyota 4Runner Clogged sunroof drains letting water into the cabin (owner reports)?
Owners of fourth- and fifth-generation 4Runners report water leaking into the cabin and onto the floor when debris clogs the sunroof drain tubes at the corners of the sunroof tray. Applies to: 2003-2024 Toyota 4Runner with a sunroof (moonroof). The owner reports linked here are f… Severity: low.
What is the 2003-2024 Toyota 4Runner 4.0L V6 oil leak at the front timing cover (owner reports)?
Owners of fourth- and fifth-generation 4Runners with the 4.0L V6 report oil leaking from the front timing cover, including low-mileage trucks repaired by the dealer under warranty. Toyota bulletin text reposted on an owner forum describes a small oil leak where the bank 1 cylinde… Severity: low.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.