2021 BMW Z4
Vehicle Specs & Maintenance Data
The 2021 BMW Z4 maintenance specs on this page cover the key fluids, torque values, and wear items you need for routine service. Use these numbers as a quick reference when performing oil changes, tire rotations, brake jobs, and other scheduled maintenance on your BMW Z4.
For oil changes, the 2021 BMW Z4 takes 0W-30 Full Synthetic motor oil with a capacity of 6.9 quarts. Brake fluid type is DOT 4, the recommended coolant is BMW Coolant (Blue, phosphate-free), and transmission fluid is ZF Lifeguard 8 (ATF). Always use the manufacturer-recommended fluids to maintain warranty coverage and engine longevity.
When mounting wheels on the BMW Z4, torque the lug nuts to 103 ft-lbs using a calibrated torque wrench. Over- or under-torquing can lead to warped brake rotors or loose wheels. Re-torque after 50 to 100 miles on newly installed wheels.
Owners of the 2021 BMW Z4 have reported 5 common issues including "B48 Engine Oil Filter Housing Gasket Leak", "Convertible Soft Top Hydraulic Leaks" and "Infotainment System Software Glitches". Scroll down to the Diagnostics tab for detailed descriptions, solutions, and estimated repair costs.
There are 5 NHTSA safety recalls on file for the 2021 BMW Z4. Check the Recalls tab below for full details.
Specifications on this page are compiled from multiple publicly available sources including manufacturer documentation, NHTSA data, and automotive databases. Always cross-reference with your owner's manual or official factory documentation before purchasing parts or performing any service.
The 2021 BMW Z4 uses 0W-30 Full Synthetic motor oil (6.9 qt capacity), requires lug nuts torqued to 103 ft-lbs, takes DOT 4 brake fluid.
Manufacturer-recommended maintenance schedule for the 2021 BMW Z4. Always verify intervals against your owner's manual.
Enter a diagnostic trouble code to see causes, symptoms, and fixes for the 2021 BMW Z4.
Common problems reported by 2021 BMW Z4 owners, with recommended fixes and estimated repair costs.
B48 Engine Oil Filter Housing Gasket Leak
The B48 2.0L turbo engine oil filter housing gasket deteriorates and leaks oil onto the exhaust manifold, creating a burning oil smell and smoke. This is one of the most common B48 engine issues across all BMW models.
Replace the oil filter housing gasket and clean the affected area. The repair involves removing the intake manifold for access. Use the updated gasket part number to prevent recurrence.
Est. Cost: $500 - $1,200Convertible Soft Top Hydraulic Leaks
The power soft top hydraulic system develops leaks at the cylinder seals and hydraulic lines, causing the top to operate slowly or stop midway through its cycle. Fluid drips into the trunk area and can damage electronics.
Repair or replace the leaking hydraulic cylinders and lines. Flush and refill the hydraulic system with fresh fluid. Check the hydraulic pump motor for damage from running dry. Protect trunk-area electronics from fluid contamination.
Est. Cost: $800 - $2,500Infotainment System Software Glitches
The iDrive 7.0 system experiences crashes, wireless CarPlay disconnections, and navigation blackouts. The system may reboot while driving, temporarily disabling backup camera and climate displays.
Dealer performs iDrive software updates via USB or over-the-air. Hard reset of the head unit may resolve persistent issues. In severe cases, the head unit requires replacement.
Est. Cost: $0 (software update) - $2,000 (head unit)Coolant Loss and Expansion Tank Cracking
The plastic coolant expansion tank develops micro-cracks, causing slow coolant leaks and low coolant warnings. The tank is pressurized and degrades over time from heat cycling.
Replace the coolant expansion tank with an updated part. Inspect radiator hoses and connections while the system is depressurized. This is a known maintenance item on BMW turbo engines.
Est. Cost: $300 - $700Timing Chain Rattle on B58 Engine
The B58 3.0L inline-6 (M40i) can develop a timing chain rattle on cold starts. While less common than the N20/N26 timing chain issues, the B58 chain tensioner can lose oil pressure after extended sitting periods.
Dealer inspects the timing chain tension and replaces the tensioner and chain if excessive wear is found. The B58 timing chain is on the rear of the engine, making it a labor-intensive repair.
Est. Cost: $2,000 - $4,0005 NHTSA safety recalls for the 2021 BMW Z4. Check your VIN at NHTSA.gov
ELECTRICAL SYSTEM:STARTER ASSEMBLY
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.
Fire increases the risk of injury.
Dealers will replace the engine starter, free of charge. Owner notification letters are expected to be mailed March 24, 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.
ELECTRICAL SYSTEM:STARTER ASSEMBLY:RELAY
Park OutsideBMW 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.
A short circuit in the starter relay may increase the risk of a fire.
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 will be searchable on NHTSA.gov beginning November 14, 2025.
ENGINE
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.
Loss of braking assist can increase the risk of a crash.
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.
SEAT BELTS
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."
During a crash, a seat belt retractor that does not function as intended increases the risk of injury.
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).
FUEL SYSTEM, GASOLINE:STORAGE:TANK ASSEMBLY
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.
The failed weld may allow fuel to leak, increasing the risk of a fire in the presence of an ignition source.
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.