2021 Subaru Ascent engine problems

Filed Nov 5, 2026 · Engine, Transmission · NV

Twin Falls Subaru left me in a dangerous position with my transmission failing catastrophically on the highway 72 hours after major service is a severe safety hazard My 2021 Subaru Ascent with 56,420 miles, still under the 60,000 mile/5 year warranty, went to Twin Falls Subaru with diagnostic codes P0137, and P2096 on 8/15/26 they replaced the following, the engine harness,. transmission harness, transmission pressure sensor and ecm. They said the root problem was the secondary pressure switch, Subaru of America & Twin Falls Subaru said those repairs weren’t covered under warranty and I had to pay $3000 out of pocket, SOA covered the remaining $5100. I picked it up 10/13/26, (on 10/16/26, three days later my check engine light came on along with the AT oil temp and transmission flashing on the dash, the diagnostic codes I received were P0700 P0841 P0890, Subaru Of America paid to have my vehicle towed back to the dealership where they said I needed a new transmission, but they weren’t covering it because my warranty had expired 14 days prior (on 10/2/26), during the time it was getting the first repairs done, they claimed that the two incidents had nothing to do with one another. The DPSM claims a transmission pressure switch failure that flooded the wiring harness with fluid is 'unrelated' to the transmission total collapse 72 hours later. They

Filed Jul 29, 2026 · Engine, Transmission · CA

My 2021 Subaru Ascent (40,000 miles) suffered multiple major mechanical failures that pose ongoing safety concerns: 1. Engine Oil Leak: The vehicle developed an active engine oil leak at 20,000 miles, posing a risk of fluid contacting hot exhaust/engine components under the hood or causing low oil levels during operation. Repair time more than 35 days due to parts not available. 2. Loose Factory Engine Mounts: At 25,000 miles, excessive engine shifting, vibration when braking, the dealer discovered loose engine mounts. 3. Transmission Valve Body Failure: At 40,000 miles The transmission Valve Body Failure and need replacement.

Filed Jul 11, 2026 · Engine · IA

Oil leaking from upper and lower oil pan. Oil seeping from head gasket and CVT chain pump cover. RTV sealant failure. $4800 to repair. Subaru needs to solve these oil leak issues. Leaking oil is bad for the environment and engine failure could cause accidents and injury.

Filed Jun 25, 2026 · Brakes, Engine · TX

On May 14, 2026, while driving a 2021 Subaru Ascent (approx. 94,291 miles) on a Texas expressway at highway speed during rush hour, I experienced a sudden and significant loss of engine power. There were no warning lights, no safety system activation, and no advance indication of the failure. The vehicle decelerated abruptly with traffic behind it. Live OBD-II data was being logged during the drive and was provided to the service advisor at the authorized Subaru retailer. This incident occurred only 3 days and approximately 125 miles after the vehicle was returned following a major engine repair performed at an authorized Subaru retailer in Texas under active powertrain warranty. That repair was supervised by a Subaru of America District Quality Manager and Field Technical Specialist, who conducted a 110-mile validation drive prior to release. Prior to the highway failure, visible fluid leaks were documented across the intake ducting, residue on lower engine components, a sweet and burning odor after driving, and milky sludge returning to the coolant reservoir — all within 125 miles of pickup. These are consistent with ongoing oil and coolant cross-contamination, which was the original diagnosis documented in the dealership's digital service portal. The vehicle has now undergone three major engine teardowns since March 17, 2026 — over 100 days out of service — for the same underlying powertrain issue on the FA24 engine. The current repair involves cylinder heads sent to a third-party machine shop. Vehicle telematics confirm the vehicle has not been started since May 27, 2026. This report is filed to establish a federal safety record of the highway power loss incident and the recurring nature of this powertrain failure. An active Subaru of America customer advocacy case is on file regarding this vehicle.

Filed Jan 20, 2026 · Electrical, Engine · NY · fire

While driving my Subaru Ascent, a check engine warning light appeared on the dashboard. Shortly afterward, I noticed smoke coming from the engine compartment. I immediately pulled over and turned the vehicle off. Within moments, flames began coming from under the hood. The fire spread rapidly, and within 5-10 minutes the entire vehicle was fully engulfed in flames. The fire originated from the engine compartment. The vehicle was a total loss. Subaru of America was notified on 12/23/2025, but no follow-up or update on investigation has been responded. The vehicle was always serviced with Subaru. This sudden, traumatizing and catastrophic failure with no prior warning.

Filed Jan 13, 2026 · Electrical, Engine · CO

The transmission on our 2021 Subaru Ascent is slipping and failing to accelerate, RPMs reving, and every issue indicator notification light is on. We took the car to our mechanic, then to the Subaru dealership service dept for diagnosis. A full transmission replacement is required plus associated repairs for a cost of $14,543.98. Service estimate attached. This repair is more than 2/3 of the value of the vehicle. This make/model and transmission type have documented problems and Subaru has previously issued an extended warranty on other model years for this same transmission issue. We are trying to communicate with the Subaru customer service but have had limited response due to the holidays and have not had a resolution yet in the past month.

Filed Dec 26, 2025 · Engine · WA

Vehicle smells of fuel inside the cabin and when parked in the garage. To date the dealer is unable to diagnose the problem. 60k miles

Filed Sep 24, 2025 · Brakes, Engine · MA

Oil leak from engine constantly from FRONT DIFFERENTIAL, rec cvt pump reseal with new trans seal, pump is leaking causing drips ; drain plug is also leaking. Need to Replace Front and rear Pads & Rotors at 35k miles which is unheard of. Accessed by suberu dealership.

Filed Oct 3, 2024 · Engine · OK

Transmission needed a full replacement

Filed Apr 4, 2023 · Engine, Transmission · CA

The transmission of my 2021 Ascent regularly slips or shutters when trying to accelerate time to time(not always). Loud noises when shifting from low speed. Went to dealership but they said car working perfectly.