The 2020 Z4 M40i shares the Toyota Supra platform and B58 engine—generally solid, but early G29 chassis examples saw transmission cooling issues and some catastrophic B58 bearing failures tied to low-speed pre-ignition (LSPI) on tune-happy cars or neglected oil changes.
Transmission Oil Cooler Failure / Leaking
Occasional · medium severity
Typical onset: 30,000-60,000 mi
Symptoms: Transmission fluid puddle under car, often pink/red staining, Harsh shifting or delayed engagement when fluid is low, Check engine light with transmission overtemp codes
Fix: Replace cooler and lines, flush system. 3-4 hours labor. Common on early ZF 8HP models; revised part available.
Estimated cost: $800-1,400
B58 Connecting Rod Bearing Wear / Spun Bearing
Rare · high severity
Typical onset: 40,000-80,000 mi
Symptoms: Knocking or ticking noise on cold start that doesn't go away, Sudden loss of oil pressure, engine warning light, Metallic debris in oil during change
Fix: Full engine rebuild or short-block replacement. 20-30 hours labor depending on extent. Worst-case scenario if LSPI event occurs or extended oil change intervals. Not widespread but catastrophic when it happens.
Estimated cost: $8,000-15,000
Transmission Mount Failure
Common · low severity
Typical onset: 50,000-90,000 mi
Symptoms: Clunking when shifting into drive or reverse, Excessive drivetrain movement felt through chassis, Vibration at idle in gear
Fix: Replace trans mount. 1.5-2 hours labor. Hydraulic mount design degrades faster with spirited driving.
Estimated cost: $400-700
High-Pressure Fuel Pump (HPFP) Failure
Occasional · high severity
Symptoms: Long crank / no-start condition, Rough idle, misfires under load, Fuel pressure fault codes, limp mode
Fix: Replace HPFP on intake side of engine. 2-3 hours labor. Some B58s got updated pump design; failure often tied to bad fuel or contamination.
Estimated cost: $1,200-2,000
Coolant Thermostat / Housing Leaks
Occasional · medium severity
Typical onset: 60,000-100,000 mi
Symptoms: Coolant weeping from front of engine, Overheating or slow warm-up, Sweet smell after driving
Fix: Replace thermostat and housing assembly. 2-3 hours labor. Plastic housing fatigues; do water pump at same time if high mileage.
Estimated cost: $600-1,100
Soft-Top Mechanism Binding / Motor Failure
Occasional · low severity
Symptoms: Roof stops mid-cycle, error message on dash, Grinding or clicking noise during operation, Manual release required to close/open
Fix: Lubricate rails and pivots; replace motor or microswitch if mechanical failure. 1-3 hours labor depending on component. Keep drains clear to avoid water intrusion.
Estimated cost: $300-1,500
Owner tips
Change oil every 5,000 mi or less, especially if tuned—LSPI kills bearings on the B58 when oil degrades
Inspect transmission cooler lines annually; early failures leave you stranded
Use Top Tier fuel exclusively and consider occasional Italian tune-up to prevent carbon buildup on direct-injection valves
Keep convertible top drains clear with compressed air twice a year—clogs cause interior flooding and electrical gremlins
Buy a 2020+ with full service records and confirm no tuning history—solid platform if maintained, but bearing failures and trans cooler issues make a pre-purchase inspection with oil analysis mandatory.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
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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: 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 will be searchable on NHTSA.gov beginning November 14, 2025.
ENGINE · 21V598000
2021-08-02
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: 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.
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: 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.
EXTERIOR LIGHTING:HEADLIGHTS · 20V516000
2020-08-27
BMW of North America, LLC (BMW) is recalling certain 2019-2020 Z4 sDrive30i, Z4 M40i and 2020 Toyota Supra vehicles. The headlamps are able to be adjusted horizontally. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices and Associated Equipment."
Consequence: Should the headlamps be adjusted horizontally, there could be increased glare and reduced visibility for oncoming drivers, or reduced visibility for the vehicle operator, thereby increasing the risk of a crash.
Remedy: BMW will notify owners, and dealers will inspect the headlamp vertical and horizontal adjustment plugs, correcting them as necessary, free of charge. The recall began December 23, 2020. BMW owners may contact BMW customer service at 1-800-525-7417 or Toyota owners may contact Toyota customer service at 1-888-270-9371.
EXTERIOR LIGHTING:HEADLIGHTS · 19V850000
2019-11-27
BMW of North America, LLC (BMW) is recalling certain 2020 Z4 M40i, Z4 sDrive30i, 330i and 330i xDrive vehicles as well as 2020 Toyota Supra vehicles. The headlight control units may fail causing a loss of one or both of the headlights.
Consequence: Headlight failure can reduce the driver's visibility, increasing the risk of a crash.
Remedy: BMW will notify owners, and dealers will replace the headlight control units, free of charge. The recall is expected to begin January 17, 2020. Owners may contact BMW customer service at 1-800-525-7417 or Toyota customer service at 1-888-270-9371.
BACK OVER PREVENTION: SENSING SYSTEM: CAMERA · 19V684000
2019-09-27
BMW of North America, LLC (BMW) is recalling certain 2018 540d, 2018-2020 530i, 530i xDrive, 540i, 540i xDrive, M550i xDrive, M5, 530e, 530e xDrive, X3 sDrive, X3 xDrive, X3 M40i, X3 M, and 2019-2020 X4 xDrive, X4 M40i, X4 M, X7 xDrive, X7 M50i, 740Li, 740Li xDrive, 750Li, 750Li xDrive, 8 Series Convertible and Coupe 840i, 840i xDrive, M850i xDrive, X5 sDrive, X5 xDrive, X5 M50i, X6 xDrive, X6 M50i, 330i, 330i xDrive, M340i, M340i xDrive, Z4 sDrive, Z4 M40i, 740Le xDrive and 745Le xDrive, 2018-2019 640i xDrive Gran Turismo and Rolls-Royce Phantom, 2019 M850i xDrive Gran Coupe and Rolls-Royce Cullinan and 2020 Toyota Supra vehicles.
The back-up camera and display settings can be adjusted such that the rear view image is no longer visible and the system will retain that setting the next time the vehicle is placed in reverse. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 111, "Rearview Mirrors."
Consequence: The lack of an image in the back-up camera display increases the risk of a crash.
Remedy: BMW will notify owners, and dealers will update the back-up camera software, free of charge. The recall began November 8, 2019. Owners may contact BMW customer service at 1-800-525-7417 or Rolls-Royce at 1-877-877-3735. Toyota owners may contact Toyota customer service at 1-888-270-9371.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.