IllustrationThere is a strong chemical smell when the AC is turned on and the system is loosing refrigerant. There is a common issue on these cars of premature evaporative core corrosion.
2021 BMW Z4
Owner reports · Recalls · Investigations
Limited comparison data
There is not enough comparable history to draw a useful model-year comparison.
About this comparison →How this year compares
Owner complaints by model year
Compare all Z4 years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 0 of 1 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
NHTSA owner reports · September 18, 2026 snapshot.
0 crash reports0 fire reports0 injury reports
Unknown Or Other complaints
1 reportsOfficial recalls
526V056000 · Electrical System:starter Assembly
Jan 30, 2026
BMW of North America, LLC (BMW) is recalling certain 2021-2023 Toyota Supra, 2022-2023 2 Series Coupe, 2021-2024 5 Series (xDrive), 2021-2022 Z4, 2022-2024 4 Series (Gran Coupe), 2021-2024 4 Series (Convertible and xDrive Convertible), 2021-2023 4 Series (Coupe), 2021-2024 3 Series, 2021-2023 X4, 2021-2024 X3 vehicles. Please see the recall report for a complete list of all models. The engine starter may overheat and catch fire due to wear on an internal component.
Consequence & remedy
Consequence: Fire increases the risk of injury.
Remedy: Dealers will replace the engine starter, free of charge. Owner notification letters were mailed July 21, 2026. Owners may contact BMW customer service at 1-800-525-7417 or Toyota's customer service at 1-800-331-4331. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning March 24, 2026.
25V636000 · Electrical System:starter Assembly:relay
Sep 23, 2025
BMW of North America, LLC (BMW) is recalling certain 2019-2021 BMW 330i, 2019-2022 BMW Z4, 2020-2022 BMW 530i, X3, X4, Toyota Supra, 2021-2022 BMW 430i, 430i Convertible, and 2022 BMW 230i vehicles. The engine starter relay may corrode, causing the relay to overheat and short circuit.
Consequence & remedy
Consequence: A short circuit in the starter relay may increase the risk of a fire.
Remedy: Owners are advised to park their vehicles outside and away from structures until the remedy is complete. Dealers will replace the engine starter, free of charge. Owner notification letters were mailed February 6, 2026. Owners may contact BMW customer service at 1-800-525-7417. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov November 14, 2025.
21V598000 · Engine
Aug 2, 2021
BMW of North America, LLC (BMW) is recalling certain 2020 M340i, M340i xDrive, 540i, 540i xDrive, X3 M40i, 2020-2021 X4 M40i, 745Le xDrive, 2019-2021 Z4 M40i, and 2020-2021 Toyota Supra vehicles. During engine start, the engine management software may cause loss of braking assist. Full mechanical braking (without assist) remains available.
Consequence & remedy
Consequence: Loss of braking assist can increase the risk of a crash.
Remedy: Dealers will update the engine management software, free of charge. Owner notification letters were mailed on September 17, 2021. Owners may contact BMW customer service at 1-800-525-7417.
21V554000 · Seat Belts
Jul 21, 2021
BMW of North America, LLC (BMW) is recalling certain 2021 2 Series (230i, 230i xDrive, M240i, M240i xDrive), 330e, 330e Xdrive, 4 Series Coupe (430i, 430i xDrive, M440i xDrive) M4 Coupe, M4 Competition Coupe, BMW 4 Series Convertible (430i, M440i), BMW X1 sDrive28i, xDrive28i, 2 Series Gran Coupe (228i, 228i xDrive, M235i xDrive), M2 Competition Coupe, 330i, 330i xDrive, M340i, M340i xDrive, M3, M3 Competition, 530i, 530i xDrive, 540i, 540i xDrive, MINI Hardtop 2 Door (Cooper, CooperS, JCW), X2 sDrive28i, X2 xDrive28i, X2 M35i, Z4 sDrive30i, Z4 M40i, MINI Hardtop 2 Door (Cooper SE), MINI Convertible (Cooper, Cooper S, JCW), MINI Clubman (Cooper S, Cooper S All4, JCW), MINI Countryman (Cooper, Cooper All4, Cooper S, Cooper S All4, JCW All4), Rolls Royce Ghost, MINI Countryman (Cooper S E All4), Rolls Royce Phantom, Rolls Royce Cullinan, and Toyota Supra vehicles. The passenger seat belt Automatic Locking Retractor (ALR) may deactivate early, before the webbing fully retracts. As such, these assemblies fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."
Consequence & remedy
Consequence: During a crash, a seat belt retractor that does not function as intended increases the risk of injury.
Remedy: Dealers will inspect the seat belt retractors (including the seat belts) and, if necessary, replace the retractors, free of charge. Owner notification letters were mailed on September 3, 2021. Owners may contact BMW customer service at 1-800-525-7417; 1-866-825-1525 (MINI); 1-877-877-3735 (Rolls Royce); and 1-888-270-9371 (Toyota).
20V700000 · Fuel System, Gasoline:storage:tank Assembly
Nov 12, 2020
BMW of North America, LLC (BMW) is recalling certain 2020-2021 Z4 and 2020-2021 Toyota Supra vehicles. The weld between the fuel tank halves may have been insufficiently welded, causing the weld to fail.
Consequence & remedy
Consequence: The failed weld may allow fuel to leak, increasing the risk of a fire in the presence of an ignition source.
Remedy: BMW will notify owners, and dealers will replace the fuel tank, free of charge. The recall began December 18, 2020. Owners may contact BMW customer service at 1-800-525-7417 or Toyota customer service at 1-888-270-9371.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0No exact-year investigations in this snapshot.