2021 Lexus IS Problems: 1 Issues Every Owner Should Know
2021 model year · 1,800+ owner reports · Updated April 2026
According to Au7o's analysis of 1,800+ owner reports, the 2021 Lexus IS has 1 documented known issues. No issues are rated critical, indicating generally reliable ownership. The most commonly reported issue is Carbon Buildup on Intake Valves (2.0T) with 1,800 owner reports. Across all issues, repair costs range from $400 to $800. DIY maintenance guides at au7o.io.
All 1 Known Issues
On the 2016-2022 Lexus IS 2.0L 8AR-FTS Turbo, the direct-injected 2.0L turbo four-cylinder in the IS200t/IS300 accumulates heavy carbon deposits on the intake valves since fuel is not sprayed over the valves to clean them. This leads to rough idle, hesitation under acceleration, and reduced power output typically between 40,000-80,000 miles.
Common Symptoms
- Rough idle or engine vibration
- Hesitation on acceleration from stop
- Reduced power and sluggish throttle response
- Slight misfire feel at low RPM
- Decreased fuel economy
How to Fix
Perform a walnut shell blasting of the intake valves to remove carbon deposits. This requires removing the intake manifold and using specialized media blasting equipment. Plan to repeat every 40,000-60,000 miles. Using a quality catch can helps slow the buildup rate.
What Owners Are Using
Parts and tips from 1,800+ owners who fixed this issue
- UpgradeJLT Performance oil catch can — catches oil vapor before it reaches the intake valves, significantly reducing carbon buildup between walnut blasting services. (JLT Performance #JLT-3012P)