There 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.
The worst 2021 BMW Z4 problems
Ranked by number of owner complaints. Mileage and cost come from what owners wrote.
Problems by type
Tap a problem to see which part fails, at what mileage and in which other years.
Recalls 5
Electrical system: starter assembly
- What is wrong
- 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.
- Risk
- 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 beginning March 24, 2026.
Recall number 26V056000 · Recall details
Electrical system: starter assembly: relay
- What is wrong
- 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.
- Risk
- 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 November 14, 2025.
Recall number 25V636000 · Recall details
Engine
- What is wrong
- 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.
- Risk
- 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.
Recall number 21V598000 · Recall details
Seat belts
- What is wrong
- 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."
- Risk
- 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).
Recall number 21V554000 · Recall details
Fuel system, gasoline: storage: tank assembly
- What is wrong
- 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.
- Risk
- 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.
Recall number 20V700000 · Recall details
Technical service bulletins for the 2021 BMW Z4 115
Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.
- The EVAP systems purge (vent) valve limited warranty for defects in materials or workmanship has been...
- While driving on an uneven road, a “clicking”sound is heard from the front bow/cowl panelarea of the...
- The convertible top does not open or close.
- An interference noise (groaning noise) can be heard from within the heating and air-conditioning unit in...
- The basic conditions for initializing the power windows are not met.
- The electrical system of BMW vehicles has been subject to an ongoing development process over the last few...
- At low outside temperatures (below 40 degrees F) and slow driving speeds (i.e. when parking,...
- A vehicle arrives at your center to be diagnosed for a micro-leak in the fuel evaporative (EVAP)...
- The Central Information Display goes black intermittently due to resets of the Head Unit (HU-H3)....
- ?The outer A-pillar trim panel (arrow) protrudes outward (circled) towards the cowl seal.
2021 BMW Z4 fuel economy
Official EPA estimates in miles per gallon (MPGe for electric). Ranges cover trims that share the same engine.
| Engine | Drive | City | Highway | Combined |
|---|---|---|---|---|
| 2.0L 4‑cyl | RWD | 25 | 32 | 28 |
| 3.0L 6‑cyl | RWD | 22 | 30 | 25 |
What 2021 BMW Z4 owners say
Most recent owner complaints, unedited.
Compare the 2021 BMW Z4
Other model years
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Questions about the 2021 BMW Z4
Is the 2021 BMW Z4 reliable?
Owners have filed 1 complaint about the 2021 BMW Z4, fewer than a typical Z4 model year.
What is the most common problem with the 2021 BMW Z4?
There are not enough complaints to tell.
How many recalls does the 2021 BMW Z4 have?
5 recalls, covering electrical system, engine and seat belts.
What gas mileage does the 2021 BMW Z4 get?
Official estimates for the 2021 BMW Z4 range from 25 to 28 mpg combined. The most efficient version (2.0L 4-cyl, RWD) gets 25 city and 32 highway.
VIN decoder
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