2021 Subaru Forester Problems: Known Issues by Mileage

✅ The short verdict

Known issues, but few dealbreakers The 2021 Forester is one of the better years in the lineup. The headline complaints are a slow-draining 12V battery and infotainment glitches, both early and cheap to fix. There is no widespread engine or transmission failure pattern on this year. Buy with confidence, but verify the battery, software updates, and oil level before you sign.

Subaru redesigned the Forester for 2019, so by 2021 the platform had three years to mature. The 2.5L FB25 boxer engine was updated for direct injection in 2019, which largely fixed the heavy oil burning that plagued 2011 to 2018 models. Most 2021 owners report few surprises, and many cross 100,000 miles on routine maintenance alone. The problems below are real but manageable, and knowing them gives you leverage at the dealer.

📊 Most-reported problems by mileage

This table ranks the issues 2021 Forester owners actually report, roughly in order of how common they are, with the mileage window they tend to appear and a realistic repair cost.

Problem	Typical Mileage	Repair Cost	Severity
12V battery drain / dead battery	5k–30k	$180–$300	Minor nuisance
Infotainment freeze / Bluetooth dropouts	0–25k	$0 (software update)	Minor
Minor oil consumption (1 qt / 3k–5k mi)	20k–80k	$10 top-off	Watch & document
CVT shudder / hesitation	30k–70k	$0–$400 (warranty)	Covered to 100k
Brake premature wear / squeal	25k–50k	$250–$450/axle	Routine
EyeSight false alerts / windshield cost	any	$900–$1,500 windshield	Costly if cracked
AC compressor / climate noise	40k–90k	$700–$1,200	Uncommon

🔎 The breakdown

1. Dead 12V battery (the #1 complaint)

This is the issue you will hear about most. Owners find the car dead after it sits for three to five days, especially in cold weather. The culprit is parasitic draw from the always-on telematics and infotainment modules paired with a smallish factory battery. Subaru issued software updates to reduce the drain, and a fresh AGM battery usually ends it. If you are buying used, ask whether the battery has been replaced and whether dealer software updates are current. A jump-start that becomes a habit points straight at this. See our guide on a car that clicks but won't start for the quick test.

2. Infotainment and Bluetooth glitches

The Starlink head unit on early 2021 builds can freeze, drop Apple CarPlay, or lose Bluetooth pairing. Almost all of this is fixed by a free dealer software update. If a test-drive car still glitches, it likely missed its updates, which is also a clue about how the battery drain was handled.

3. Oil consumption (much improved, still worth watching)

The 2019 switch to direct injection cut oil burning dramatically versus older Foresters. A quart every 3,000 to 5,000 miles falls inside Subaru's normal range. Check the dipstick between changes. If you see more than a quart per 1,200 miles, document it, because Subaru runs an oil consumption test under powertrain warranty. Compare notes on our Subaru burning oil page.

4. CVT behavior

The Lineartronic CVT is generally reliable on this year. A minority of owners feel shudder or a brief hesitation from a stop, usually cured by a fluid service or a control-module reflash. A prior class-action settlement extended CVT coverage to 10 years or 100,000 miles on many Subarus, so confirm coverage applies to your VIN before paying out of pocket. If you feel slipping or flaring RPM, read CVT transmission slipping first.

5. EyeSight and the windshield gotcha

EyeSight works well, but its cameras sit at the top of the windshield. A cracked windshield means a calibrated replacement that can run $900 to $1,500, far more than a normal pane. False forward-collision or lane-departure alerts usually trace to a dirty camera, glare, or a windshield that was replaced without recalibration.

⚠️ What to watch for before you buy

If you are shopping a used 2021 Forester, this 5-minute checklist separates a clean car from a headache:

Battery test. Ask when it was last replaced and have it load-tested. A weak battery plus stale software is the single most common 2021 gripe.
Software updates. Confirm the infotainment and BCM updates are installed. A free trip to the dealer fixes most freezing and drain complaints.
Oil level and color. Pull the dipstick cold. Low or very dark oil on a low-mileage car hints at skipped maintenance.
Windshield. Any chip near the EyeSight cameras is a future $1,000-plus bill. Walk if it is cracked and unaddressed.
CVT warranty. Verify the extended coverage still applies to the VIN so any future shudder is on Subaru, not you.
Brakes. Listen for squeal and check pad thickness. Early Forester pads can wear faster than expected.

Getting a repair quote that feels high? Run it through our repair quote checker before you agree to anything.

🧮 Is it a dealbreaker? A quick framework

Use this logic to decide whether a specific 2021 Forester is worth it:

Battery or infotainment only? Not a dealbreaker. These are cheap or free fixes. Use them to negotiate a few hundred dollars off.
Mild oil use, level maintained? Normal. Keep checking the dipstick and you are fine.
CVT shudder under warranty? Get it documented now, but coverage protects you. Still buyable.
Cracked EyeSight windshield, ignored? Price in $1,000-plus or walk. This is the most likely surprise bill.
Repeated unexplained stalls, hard shifts, or CEL? Stop and diagnose. Pull codes and check our P0420 and other DTC guides before committing.

Most 2021 Foresters land in the first three buckets, which is why this year earns a generally positive verdict.

❓ Frequently asked questions

Is the 2021 Subaru Forester a reliable car?

Overall yes. The 2021 Forester is one of the better model years in the lineup and earns above-average reliability scores. The most common complaints are a slow-draining 12V battery, occasional infotainment glitches, and minor oil consumption rather than catastrophic engine or transmission failures. Most issues are inexpensive nuisances, not dealbreakers.

Do 2021 Subaru Foresters have battery problems?

Battery drain is the single most reported 2021 Forester issue, usually showing up in the first 10,000 to 30,000 miles. Owners find a dead 12V battery after the car sits a few days. Subaru addressed parasitic drain with software updates, and a fresh AGM battery plus the latest infotainment update typically resolves it. Replacement runs about $180 to $300.

Does the 2021 Forester burn oil?

Some 2021 Foresters consume a quart of oil every 3,000 to 5,000 miles, which is within Subaru's stated normal range. It is far less severe than the older FB25 engines from 2011 to 2018. Check your dipstick between changes and top off as needed. Excessive consumption beyond one quart per 1,200 miles is worth documenting for warranty.

Is the CVT in the 2021 Forester a problem?

The Lineartronic CVT in the 2021 Forester is generally solid and carries a 10-year, 100,000-mile extended warranty from a prior class-action settlement. A small number of owners report shudder or hesitation, often fixed with a fluid service or software reflash. Outright CVT failure is rare on this model year.

At what mileage do 2021 Forester problems start?

Battery and infotainment complaints cluster early, often under 30,000 miles. Minor oil consumption and brake or suspension wear show up between 40,000 and 80,000 miles. Major mechanical issues are uncommon, and many owners pass 100,000 miles with only routine maintenance.

📝 TL;DR

The 2021 Subaru Forester is a reliable, value-holding SUV with a few known but minor problems. Watch the 12V battery drain (the top complaint), keep infotainment software current, and check oil between changes. The CVT is covered to 100,000 miles, and a cracked EyeSight windshield is the only routinely expensive surprise. None of these are dealbreakers on a well-kept example. Verify before you buy and you are getting one of Subaru's stronger model years.