2021 Subaru Forester Engine problems

When coming to a stop, the auto start/stop system shuts the engine off and it fails to restart. All dashboard warning lights illuminate. The vehicle must be shifted to Park and restarted manually with the start button. The component that failed is the auto start/stop system; the exact cause is UNKNOWN. The vehicle is available for inspection upon request. This put safety at risk because the vehicle was left immobile in live traffic at stops until it could be restarted. There were no warning lamps or symptoms before...

Component Failed & Inspection Availability: The vehicle suffered a sudden, catastrophic mechanical engine block failure at 74,000 miles. The dealership teardown confirmed a failed/spun lifter bearing and a fractured connecting rod cap, requiring a complete engine replacement. This sudden oil pressure failure/blockage occurred while the engine oil pan was verified completely full. This sudden mechanical failure is directly consistent with severe localized thermal breakdown from a failing Thermo Control Valve (TCV) - a...

I was stopped at a red light. When the light changed to green I put my foot on the gas and the car totally stalled out. There were no lights, fans or radio on just total silence. I tried to restart the car putting it is park and depressing the brake while pushing the start button and nothing. It didn't even try to turn over. silent, dead. I tried several times with no luck. I got out of the car to signal to the bus and row of cars behind me to pass me. I got back into the car and tried to start it again and...

On two separate occasions, less than one year apart after Subaru Service replaced my battery with a "larger" battery without my knowledge my vehicle suffered sudden, catastrophic electrical failure while moving in active highway traffic, causing an immediate loss of propulsion and creating a life-threatening safety hazard. This has happened two times the second time less than a year after the "larger" battery replacement. This car has less than 50,000 miles on it and has a perfect service record all done at...

My 2021 Subaru Forester has a recurring, worsening defect in the Idle Stop/Start (ISS) system that creates a stalling hazard. When ISS shuts the engine off at a stop, the engine intermittently fails to restart when I try to move again. It cranks progressively slower, warning lights illuminate, a continuous alert sounds, and the vehicle cannot proceed until I shift to Park and restart manually. This has left me immobile in live traffic at lights, stop signs, and mid-turn. The system also attempts to shut down in...

While driving this car on April 4, 2026 at around 6PM, I experienced the distinct smell of gasoline. I had driven for about 5 minutes on our way to a local restaurant that is approximately an 8 minute drive from our residence. My wife said that she had just filled the gas tank that afternoon. After arriving at the restaurant, I checked the gas cap to ensure it was tightly sealed. I also checked to ensure no fuel was leaking from the car. After finishing dinner, we I drove the car back to my residence and once...

While driving the car, the engine stops completely. After a few seconds, it can be restarted. It does this several times a week at random intervals. It's very dangerous since it usually happens when we're driving in traffic. The dealer checked it out in July but couldn't find anything wrong. Even though it's a serious safety problem, they said to keep driving it until it does it every time the car is driven or until the car won't run. When this happens, all the dashboard warning lights come on and the word "Eyesight" is displayed with a diagonal line through it. A warning buzzer also sounds. This started last summer with very infrequent occurrences and is now several times a week.

Automatic start/stop fails to turn car on - intermittent. Taken it to Subaru detailer miltiple times and paid for services to correct the issue, but the issue persists. Fist time - replaced the battery in July 2025. 2nd time, went on a ride along for 1 hour, issue did not happen, replaced spark plugs, issue persists. 3rd time, updated TCM software, issue still persists. Subaru of America is aware of the issue and have not gotten a resolution either.

The contact owned a 2021 Subaru Forester. The contact stated that while driving at approximately 4 MPH and slowing to park, the vehicle accelerated on its own. The contact stated that the vehicle drove out of the parking lot and crashed into a wall. The contact stated that the air bags deployed and that the vehicle had then shifted into reverse (R) and driven out away from the wall and crashed into a parked vehicle and stopped. The contact stated she was unaware of any warning lights. The contact stated that she...

Car drains battery. 45,000 miles and has had 3 batteries and have been told it needs another. Dealer says start stop switch, requires a battery of 750 CCA and not the Subaru recommend battery. Car will die in traffic and driver seat adjusts to different positions by itself. Told that these problems will never stop unless I get a higher rated battery than required.

On January16,2026 while driving from Houston,TX to Austin TX the vehicle experienced a complete loss of power on Highway 71 W. We were traveling at approximately 70 MPH when the engine completely failed. We were forced to immediately pull over onto a narrow shoulder Our situation at that point was dire: we could not exit the vehicle as other cars were speeding by. Fortunately an emergency vehicle from the Texas Department of Transportation pulled up behind us with his emergency lights flashing. He told us we were...

The vehicle has experienced four separate engine shutdowns while stopped in traffic. Each time, the engine turned off unexpectedly, requiring a manual restart. One incident occurred near a railroad crossing with my child in the car. The vehicle also lurches forward at low speeds and hesitates when accelerating after being stopped. These issues persist despite service visits. I believe they may relate to Technical Service Bulletins regarding the Auto Start/Stop and battery systems (TSBs #16-147-24, #10232217, #07-218-23R, #10251098). Subaru service staff have acknowledged awareness of these problems. I'm submitting this complaint to ensure the safety risk is documented and investigated.

The contact owns a 2021 Subaru Forester. The contact stated that while stopped at a traffic signal, the vehicle stalled. No warning light was illuminated. The contact was able to restart the vehicle. The contact stated that on a separate occasion, while driving over railroad tracks, the vehicle stalled. No warning light was illuminated. The contact was able to restart the vehicle. The contact continued to drive, and two blocks later, the vehicle stalled. No warning light was illuminated. The contact was able to...

driving on [[redacted]] in NJ on [[redacted]] at approximately [[redacted]] my car just stopped in traffic and steering locked up and all lights came on dashboard along with a constant beeping sound-I was in the middle of a four lane highway traveling south-I could not get out of my car and feared someone would hit me as I was a "sitting duck" while cars were swerving around me-my only saving grace was that my flashers worked after I turned them on-I called roadside assistance as I was starting to panic and was...

Vehicle began surging during acceleration. Dealer stated that the Engine Intake Valves had carbon deposits that were causing performance issues including poor fuel economy, increased emissions and running concerns. The valves required a cleaning to correct the issue. This is a 4 year old vehicle with only 38,000 miles, this is unacceptable for issues like this so soon. Estimated cleaning cost is $300 and is mentioned no where in the scheduled maintenance information.

At signal/stop sign or in stop and go traffic, Engine shuts down. Car is in park. Engine (or Car) makes beeping noise when this happens. Eyesight disabled shows on the screen (however this has nothing to do with that) There's existing lawsuit for cars until 2020. This problem exists for some 2021 model as well. Similar problem: [[redacted]] This is a recurring intermittent issue. Can't reproduce consistently INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The Auto-Stop/Start feature frequently fails to properly restart the car, often causing the car to stall during the restarting process, leaving me effectively disabled on a busy road. The battery has already been replaced once.

The automatic shutoff that occurs when the vehicle stops to prevent idling, disengaged two separate times in the span of 4 days. Both incidents occurred at very busy intersections and failed to restart both times. When attempting to restart the car, lights came up on the dash, along with beeping, and failed to restart the car after the light had turned green. To restart, the car had to be completely turned off for about 60 seconds and then could be restarted. To avoid having to experience this issue again, or worse - get into an accident - I took it to the shop where they could not recreate the issue.

2021 Subaru forester limited- Stop Start when stopping at a red light. Sometimes the engine does not restart when releasing the brake pedal. Message on dash put car in park and press start. Occurred. April 24 2025 and May 5 2025

Was stopped at traffic light. Start Stop system was engaged. Engine turned off as normal. When I took my foot off the brake the engine did not engage and the Eyesight warning light came on that the Eyesight system was not functioning. Put the car in park and engaged the ignition button and the engine started. Turned off the Start Stop system and the car functioned normally after that. Have read postings on Subaru forum that this has happened to others.

12/14/24-I was stopped at a red light at a VERY busy intersection. The engine was in stop mode by the start/stop feature. When the light turned green, the car failed to start. The entire car shut down, with alarms sounding and dash lights flashing. The entire system had to reboot before I could restart the car. It was a freighting experience. Fortunately, I wasn't killed by traffic zooming by or by some person with road rage. 12/16/24-Issue evaluated by local Subaru dealer. Their evaluation was that when the...

At 40936 the valve body needed to be replaced. With such low milage vehicle is having problems.

Thermo control valve defective. Not informed one week ago when I purchased car at end of lease. Problem known to Subaru since 2019 or sooner. Would not have purchased if I had been notified about this major problem

Vehicle was parked and idling unoccupied for under 5 minutes when an extremely noxious, hot blast of fumes came from underneath the back. Black smoke immediately entered the passenger cabin through the vents and flames were visible in the engine compartment and running onto the ground. Entire vehicle was burned beyond recognition in a matter of minutes. Ten days earlier the TCV, a known problem, had been replaced at a dealership per TSB 09-80-21. The vehicle had been driven under 300 miles since the replacement. ...

The 2021 Subaru Forester had been functioning normally with no warning lights. About 25 minutes into the drive I had come to a stop light on an upward incline. When the light turned green I moved from the brake to the gas as usual. However the auto-start function on the car failed, causing the engine to stall. A loud clunking sound was heard and the dashboard lit up with multiple lights, although I do no recall which ones were illumined. I attempted to press the gas again and the car did not respond. During this...