TT: Engine Oil Leak between the Lower Oil Pan and Crank Case
full bulletin at NHTSA ↗2021 Toyota Highlander engine problems
moderate Owners of the 2021 Toyota Highlander have filed 15 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
15
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2017 Highlander | 22 |
| 2018 Highlander | 16 |
| 2019 Highlander | 26 |
| 2020 Highlander | 3 |
| 2021 Highlander (this page) | 15 |
| 2023 Highlander | 10 |
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This Service Bulletin provides updated non-electric water pump leak inspection and diagnostic tips for some 2008 – 2025 model year Toyota vehicles.
full bulletin at NHTSA ↗This Service Bulletin provides updated non-electric water pump leak inspection and diagnostic tips for some 2008 – 2025 model year Toyota vehicles.
full bulletin at NHTSA ↗This is to advise of various price adjustments that will affect Toyota Genuine Motor Oil and Long Life Coolant, effective March 1, 2024. These products are ordered through the Toyota Complete Maintenance Care (TCMC) website.
full bulletin at NHTSA ↗TSB: Some 2018 ? 2024 model year Toyota vehicles equipped with an A25A-FKS, A25A-FXS, M20A-FKS, or M20A-FXS engine may exhibit one or more of the following conditions: ?Milky/discolored engine oil. ?An ?Oil Pressure Low? warning message on the Multi-information Display (MID). ?A MIL ON condition with Diagnostic Trouble Codes (DTCs) P05202A (Engine Oil Pressure Sensor/Switch ?A? Signal Stuck in Range) and/or P052477 (Engine Oil Pressure Too Low [Severe]) present. Moisture from blow-by gases condenses and accumulates in the engine oil during short trips in extreme cold weather. When the moisture in the oil freezes, the oil pressure may drop, and the aforementioned warning indicators may displa
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2021 Highlander has a documented transmission problem that Toyota acknowledged via TSB-000821, yet owners consistently report being refused repairs. Whining noise on acceleration is the calling card—it shows up for months before the transmission quits, almost always around 60,000 miles, which conveniently matches warranty expiration. Owners then face $8,000–$11,000 replacement bills because the warranty doesn't cover it. Toyota has declined coverage on some VINs, telling owners the TSB doesn't apply to their serial number.
Engine stalling without warning is another serious complaint. One owner's engine died at 230 miles and required replacement; another had extended cranking followed by stalling at 3,400 miles, requiring fuel sensor and pump work. Both incidents created dangerous situations with the engine cutting out in traffic.
One hybrid owner discovered a punctured inverter radiator at 18,000 miles with no warning light—$1,640 to fix—and the dealership couldn't offer any factory protection from road debris.
Sealed transmission fluid design means owners cannot check levels themselves; only dealerships can inspect, raising questions about whether topped-off fluid is actually being replaced. One owner heard transmission whining for months while multiple dealers recommended Toyota, citing severity, only for Toyota to deny the repair exists.
Same Toyota Highlander engine reports on nearby years: 2018 · 2019 · 2023
Failure modes owners describe
Transmission whining and failure
Whining noise on acceleration, transmission slipping, hesitation, jolting, and eventual transmission failure requiring replacement. Multiple owners report the sound increases with throttle input and persists throughout vehicle operation. Toyota has issued TSB-000821 acknowledging the issue, but coverage varies by VIN and warranty status. Owners report transmission failure occurring as early as 60,000 miles, often right at or shortly after the 60,000-mile warranty expiration.
When: 60,000–80,000 miles; some owners report symptoms for months before failure
Symptoms owners cite: Whining noise on acceleration; Transmission hesitation in traffic; Transmission slip and unreliable acceleration; Vehicle jolts when backing up; Audible whining increases with throttle input; No warning lights or messages
Repairs/costs cited: $8,000–$11,000 for complete transmission replacement
Recalls/TSBs owners mention: TSB-000821 issued by Toyota; however, Toyota has declined repairs on some vehicles, citing VIN-specific application or warranty expiration. Owners report Toyota stating 'no recall on the issue' and refusing coverage once warranty expires at 60,000 miles.
Engine stalling without warning
Engine stalls while driving at highway speeds or during acceleration into traffic. Vehicle does not restart without assistance (towing required). Check engine light illuminates after stalling. One owner reported stalling at 230 miles; another at 3,400 miles with extended cranking beforehand. Both incidents put occupants at serious risk.
When: 230 miles; 3,400 miles
Symptoms owners cite: Engine stalls without warning while driving or accelerating into traffic; Extended cranking time before stalling (at 3,400 miles); Vehicle will not restart; Check engine light illuminated
Codes mentioned: Check engine light (code not specified)
Repairs/costs cited: At 230 miles: new engine required, owner charged $2,799.03. At 3,400 miles: fuel sensors replaced, then fuel pump replaced after second stall incident.
Recalls/TSBs owners mention: Dealer at 230 miles falsely attributed failure to bad fuel; however, Geico investigation confirmed warranty should be issued. No TSB or recall identified in narratives for stalling issue.
Stop-start system malfunction causing unintended shutdown
Automatic stop-start feature shut off engine while vehicle was in motion on the road with children aboard. No warning before shutdown. After the incident, 'High Power Consumption Partial Limit on AC/Heater Operation' message appeared.
When: Not specified
Symptoms owners cite: Engine shut off unintentionally by stop-start system while driving; No prior warning before shutdown; High Power Consumption message displayed afterward; Safety risk due to loss of propulsion in traffic
Repairs/costs cited: No repair information provided
Recalls/TSBs owners mention: No manufacturer response documented in narrative
Inverter radiator puncture and coolant leak
Inverter radiator punctured and leaking coolant, likely from road debris. Occurs on hybrid models. Owner reported no warning light or notification of the leak despite significant coolant loss. Dealership stated rock damage is a known occurrence in certain regions and suggested aftermarket protective part, but noted no factory solution available.
When: ~18,000 miles
Symptoms owners cite: Inverter radiator coolant leak; No warning light or notification despite significant coolant loss; Visible damage and coolant spraying onto inverter radiator
Repairs/costs cited: $1,640 to repair inverter radiator
Recalls/TSBs owners mention: No recall or TSB. Dealership service representative noted rock strikes are common in Arizona; no Toyota protective parts available. Suggested owner pursue aftermarket solution.
Fuel system issues (fuel pump and fuel sensors)
At 3,400 miles, vehicle exhibited extended cranking followed by stalling. Dealership replaced fuel sensors, but vehicle stalled again two days later. Fuel pump replacement then performed. Both stall incidents occurred during acceleration into traffic, creating serious safety risk.
When: 3,400 miles
Symptoms owners cite: Extended cranking time at startup; Stalling while pulling into traffic (twice); Issue recurred after fuel sensor replacement
Repairs/costs cited: Fuel sensors replaced, then fuel pump replaced
Recalls/TSBs owners mention: No TSB or recall mentioned; owner suggested vehicle should be added to recall list
Synthesized from 15 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had engine trouble with your 2021 Toyota Highlander?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2021 Toyota Highlander?
It's a documented issue but not catastrophic. 15 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 15 complaints filed, engine issues most often appear around 3,400 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/Toyota/Highlander.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.