2003 BMW Z4 Parts & Accessories

The BMW Z4 is a two-seat sports roadster with a soft top and rear-wheel drive. It's built for fun, precise handling, and open-air driving. You can see the current Z4 Roadster on the official BMW site for a good overview of engine options, tech features, and design details at the BMW Z4 Roadster page.

BMW calls it part of the Z Series of roadsters, which goes back to classic models like the Z1, Z3, and Z8. A short history of these cars is on the BMW Z Series overview.

When people talk about BMW Z4 parts and accessories, they usually mean:

• Replacement parts / spares / components to keep the car running (brakes, filters, suspension, etc.).
• Accessories and add-ons to protect, personalize, or upgrade the car (floor mats, spoilers, car covers, electronics).
• Performance upgrades / mods to improve power, sound, handling, or braking (exhausts, intakes, coilovers, big brake kits, etc.).

The Z4 has three main generations, and parts often depend on which one you own:

• E85 / E86 (1st gen, 2003-2008) - roadster and coupe, built in Spartanburg, South Carolina. Uses 4- and 6-cylinder petrol engines and both manual and automatic gearboxes. (Wikipedia)
• E89 (2nd gen, 2009-2016) - retractable hard-top roadster only (no separate coupe). Built in Regensburg, Germany, with turbo and non-turbo 4- and 6-cylinder engines. (Wikipedia)
• G29 (3rd gen, 2019-2026) - soft-top roadster again, sharing its basic platform with the Toyota Supra, and built by Magna Steyr in Graz, Austria. Uses 2.0L B48 turbo four-cylinder and 3.0L B58 turbo six-cylinder engines. (Wikipedia)

A simple way to read more about each generation is on the Wikipedia pages for BMW Z4 (E85), BMW Z4 (E89), and BMW Z4 (G29). (Wikipedia)

Knowing your exact model code, year, and engine is key when choosing Z4 spares, replacement parts, and upgrades, because fitment can change even within the same generation.

BMW Z4 engine parts include:

• Spark plugs and ignition coils
• Air, oil, and cabin filters
• Belts, tensioners, and pulleys
• Sensors (oxygen sensors, MAF/MAP, cam/crank sensors)
• Turbocharger hardware (on turbo engines)

BMW in general recommends oil changes about every 10,000 miles or 12 months, whichever comes first, on modern models using synthetic oil. (BMW of Ridgefield) Many owners of performance cars like the Z4 prefer shorter intervals (for example 5,000-7,500 miles) to help engine life.

On early Z4s (E85/E86), owners sometimes report:

• MISFIRE and limp mode related to intake DISA valves or timing issues. (BreakerLink)
• Coolant leaks and overheating from hoses or the expansion tank, especially on older cars with high mileage.

A helpful summary of engine-related issues and what to watch for is in this article on .

Cooling parts for the Z4 include:

• Radiator and radiator fan
• Water pump and thermostat
• Coolant hoses and pipes
• Expansion tank (coolant reservoir)

On some E85 Z4s, owners on the Z4 common problems forum thread mention cracks developing in the coolant expansion tank around 100,000 miles, which can cause slow leaks and overheating if not caught early.

Key tips for cooling system components:

• Replace coolant on schedule (often every 3-4 years; check your manual).
• Inspect plastic tanks and fittings for hairline cracks or staining.
• Replace the thermostat and water pump as preventive maintenance on high-mileage cars.

Transmission and driveline components for a Z4 can include:

• Manual gearbox parts (clutches, pressure plates, release bearings, seals)
• Automatic transmission service kits (filters, pans, gaskets)
• Driveshaft, flex disc (guibo), and center support bearing
• Differential seals and fluid

BMW often lists "lifetime" fluids, but many Z4 owners and independent specialists prefer changing automatic transmission and differential fluids roughly every 30,000-60,000 miles for smoother shifting and long life. This type of interval is discussed in community-collected BMW maintenance schedules, such as those shared on Z4 forums. (Z4-forum)

For manual cars, clutch kits and flywheels are common wear items, especially on performance-driven Z4s, and driveline "clunks" when shifting or reversing are widely discussed but often considered more of a comfort issue than a failure when components are still in spec. (Z4-forum)

Suspension and steering components that Z4 owners often replace or upgrade include:

• Front control arms and bushings (including "lollipop" bushings on E85)
• Rear trailing arm bushings (RTABs)
• Shocks/struts and top mounts
• Sway bars and sway bar links
• Tie rods and steering rack components

Owners report sticky steering and clunking on some early E85 cars; community fixes include adjusting the electric power steering (EPS) column and replacing worn bushings.

Performance suspension upgrades (coilovers, sport springs, upgraded dampers) can:

• Reduce body roll
• Improve turn-in
• Allow adjustable ride height and damping

When choosing suspension spares or mods, always match parts to your model code, engine weight, and intended use (street, track, or mixed).

Brake system parts for the Z4 include:

• Brake pads and rotors
• Calipers and hardware
• Brake hoses and hard lines
• ABS sensors and pump
• Parking brake shoes and cables

Reports on Z4 reliability note that brake line rust can show up on some Z4s, even at moderate mileage, especially in wet or salty climates. Regular inspection of the metal lines is recommended so you can replace them before leaks appear. (BreakerLink)

On the common problems thread, owners also mention:

• Rusted rear brake lines
• Weak handbrake feel if not adjusted correctly (Z4-forum)

For safety and performance:

• Use quality brake pads matched to your driving style (street, spirited, or track).
• Replace brake fluid about every 2 years to keep pedal feel firm and help protect ABS components.

Wheel and tire-related components and accessories:

• Factory or aftermarket alloy wheels
• TPMS (tire pressure monitoring) sensors
• Wheel bolts or studs
• Hubcentric rings (for some aftermarket wheels)
• Tire and wheel care kits

Many Z4s came with run-flat tires from the factory, but some owners switch to standard performance tires for comfort and grip. If you change tire type or size, keep overall diameter close to stock to avoid rubbing and speedometer errors.

The U.S. National Highway Traffic Safety Administration (NHTSA) has a helpful page explaining how to check tread depth, inflation, and alignment in plain language at its tire safety section.

From NHTSA guidance:

• Replace tires when tread is worn to about 2/32 of an inch.
• Check tire pressure at least once a month and before long trips.

Exhaust and intake parts and add-ons include:

• Mufflers and mid-pipes
• Catalytic converters and exhaust hangers
• Airboxes, intake pipes, and performance panel filters
• Oxygen sensors

On some E85 Z4 2.0i models, owners report occasional cracked exhaust manifolds, plus broken exhaust hangers that let the muffler droop or rattle. (Z4-forum)

Common performance upgrades here are:

• Cat-back exhaust systems to change sound and reduce weight.
• High-flow air intakes or performance filters to improve throttle response.

These parts are popular for drivers who want a bit more power and a better engine note from their BMW roadster.

Exterior parts and accessories for the Z4 include:

• Front bumpers, rear bumpers, and side skirts
• Grilles, emblems, and trim pieces
• Headlights, taillights, fog lights, and side markers
• Convertible / soft-top components and seals
• Mirror housings and glass
• Spoilers and diffusers

In the E85/E86 common problems thread, owners share issues like:

• Convertible top motors failing after water drains clog, letting water reach the motor.
• Headlight lenses fading or getting cloudy, which can often be restored by polishing.
• Rust or corrosion on some coupe tailgates and split-rim style wheels.

For G29 owners, BMW's official model pages show modern exterior details like the wide kidney grille, slim LED lights, and sport styling packages. You can see examples on the BMW Z4 Roadster overview.

Inside the Z4, popular parts and accessories include:

• Floor mats and trunk liners
• Seat covers and seat repair parts
• Shift knobs, pedals, and steering wheels
• Interior trim kits (aluminum, carbon-look, gloss black)
• Storage organizers and phone mounts

Factory Z4s often came with features like heated seats, parking sensors, and premium audio. (BreakerLink) Many owners add accessories to:

• Protect surfaces (rubber mats, seat covers)
• Upgrade comfort (armrest cushions, sunshades, wind deflectors)
• Personalize styling (colored start buttons, interior LED lighting kits)

Electrical parts and add-ons for a Z4 can include:

• Batteries and alternators
• Starter motors
• Control modules and relays
• Window regulators and door lock actuators
• Sensors (ABS, wheel speed, parking sensors)
• Infotainment, Bluetooth, and navigation add-ons
• Upgraded headlights, fog lights, and interior LED bulbs

Commonly reported electrical issues on older Z4s include:

• Convertible top electrical faults from water getting into trunk-area components.
• Door lock and handle problems, sometimes causing difficulty opening doors.
• Wiper motor and window regulator issues on early cars. (Z4-forum)

If you add electrical accessories (dash camera, radar detector, extra lights), use proper fuses and wiring and avoid overloading factory circuits.

Simple maintenance parts for any BMW Z4 include:

• Engine oil and filter
• Air filter and cabin (pollen) filter
• Spark plugs and ignition coils
• Wiper blades
• Brake pads and rotors
• Coolant, brake fluid, and power steering / differential fluid

Enthusiast discussions of BMW maintenance schedules for the Z4 suggest: (Z4-forum)

• Oil and filter: about every 7,000-10,000 miles or yearly, even if the car is driven little.
• Brake fluid: about every 2 years.
• Coolant: roughly every 3-4 years.
• Spark plugs: commonly every 40,000-60,000 miles on modern turbo engines.

Always compare these general intervals with the schedule in your specific owner's manual, which BMW offers digitally through its official support pages linked from the BMW Z Series overview site.

A few commonly reported issues, based on owner forums and reliability write-ups: (BreakerLink)

• Coolant expansion tank leaks and general cooling system wear.
• Convertible roof motor failure due to blocked drains and water ingress.
• Sticky steering, especially at warm temperatures.
• Door lock and handle problems.
• Various suspension and bushing wear (control arms, RTABs, strut mounts).

E89 (2009-2016)

• As these cars age, common BMW items like high-pressure fuel pumps, ignition coils, and turbo-related parts can need attention (similar patterns to other BMWs with N20/N54/N55-family engines).
• Convertible hard-top mechanisms and seals can require care and adjustment on high-mileage cars. (Wikipedia)

G29 (2019-2026)

• Still relatively new, so fewer high-mileage reports, but they share engines with other BMWs that have known service patterns (for example, B48 four-cylinder and B58 six-cylinder turbo engines). (Wikipedia)
• Some 2019-2022 B48-powered Z4s are part of a starter-relay fire-risk recall (see recall section below). (Car and Driver)

Overall, independent reviews and reliability writeups suggest the Z4 is generally reliable if maintained, but early models (2003, 2005, 2007) tend to show more complaints than other years. (BreakerLink)

Popular BMW Z4 performance parts and modifications:

• Suspension upgrades - sport springs, shocks, or coilovers to lower the car and tighten handling.
• Performance brake kits - larger rotors, multi-piston calipers, and high-friction pads.
• Engine tuning - software tunes (ECU remaps) for turbo engines to increase power and torque.
• Intake and exhaust - high-flow intakes and cat-back exhaust systems for better sound and response.
• Chassis braces - front and rear strut braces to stiffen the body and improve steering feel.

When adding performance parts and mods:

• Make sure upgrades match your engine (for example, B48 vs B58) and chassis (E85, E89, G29).
• Check local laws regarding noise, emissions, and lighting.
• Use alignment settings that keep the car stable in daily driving, not only on track.

Car-focused sites like CarBuzz offer a good high-level view of how the various Z4 generations drive and respond to upgrades, for example in this Z4 generations overview. (CarBuzz)

Recalls change over time, so it's smart to check your exact car by VIN. Two useful NHTSA tools:

• General recall search: NHTSA recalls search
• Direct VIN recall lookup: VIN recall lookup tool

In 2025, BMW recalled almost 200,000 vehicles with the B48 four-cylinder engine, including some 2019-2022 BMW Z4 models, due to a risk that the starter relay can corrode, short, and possibly cause an engine-bay fire. Owners of affected cars are told to park outside until the repair (starter replacement) is completed. This is covered in detail in Car and Driver's recall report.

Broader safety topics, including recalls, tire safety, and crash-test information, are also available from the main NHTSA website.

There are also 2025 news reports that BMW plans to end global production of the Z4 around 2026, after more than 20 years of the model line. You can read about that in recent coverage of the Z4's planned discontinuation.

When working with BMW Z4 parts and accessories at home:

• Use jack stands and proper jacking points; the Z4 has reinforced spots under the car for lifting.
• Disconnect the battery when working on major electrical systems or airbags.
• Follow torque specs from a repair manual so you don't strip aluminum threads or over-tighten suspension parts.
• Keep drains clear around the convertible top and trunk area to protect roof motors and electronics. (Z4-forum)
• Check for water leaks in doors, headlights, and trunk; they are talked about often in enthusiast threads.

Dedicated owner communities like are very helpful for DIY guidance and real-world fixes.

Q: How do I know which BMW Z4 parts fit my car?
A: Start with your VIN and model code (E85, E86, E89, or G29) plus the engine and build year. The VIN can be decoded and checked through tools linked from NHTSA's VIN decoder guidance. Matching those details helps you choose the correct replacement components, spares, and accessories.

Q: What Z4 parts wear out the fastest?
A: Common wear items include brake pads and rotors, tires, suspension bushings, shocks/struts, spark plugs, and cooling system parts like hoses and expansion tanks on older cars. (BreakerLink)

Q: How often should I change the oil in my BMW Z4?
A: BMW's general recommendation is about 10,000 miles or 12 months for synthetic oil, whichever comes first. (BMW of Ridgefield) Many owners of performance models choose shorter intervals (for example 5,000-7,500 miles) for added peace of mind.

Q: What are the signs of cooling system trouble on a Z4?
A: Watch for temperature spikes, coolant smell, wet spots under the front of the car, or a low coolant warning. E85 owners in particular report leaks from the coolant expansion tank and hoses at higher mileage, so checking these parts regularly is wise. (BreakerLink)

Q: Are BMW Z4 brake lines a known problem?
A: Rusted brake lines come up often in owner discussions and reliability articles. Regular inspections, especially in areas with road salt, help catch corrosion early so you can replace lines before they leak.

Q: My Z4 steering feels sticky. What parts could be involved?
A: On early E85 models, "sticky steering" can involve the electric power steering column, bushings, and alignment. Enthusiast guides explain a free fix involving an adjustment of the EPS column ring plus suspension checks. (Z4-forum)

Q: What are common convertible top issues on Z4s?
A: E85 owners often mention roof motor failure when drains clog and water reaches the motor, and E89/E85 owners report slower top operation or electrical faults. Regularly clearing drains and checking seals helps protect the top system. (BreakerLink)

Q: Is the BMW Z4 generally reliable?
A: Independent reliability summaries say the Z4 is fairly reliable when maintained, but certain years (especially some early 2000s models) have more recorded issues than others. The most expensive issues tend to be brake and cooling system repairs, not engine failures.

Q: What performance upgrades give the best "bang for the buck" on a Z4?
A: Many owners start with high-quality tires, performance brake pads, and suspension upgrades (springs or coilovers). Turbo models can also benefit from a conservative ECU tune and a freer-flowing exhaust. These mods usually offer clear gains in handling and responsiveness. (CarBuzz)

Q: Where can I learn more about my specific Z4 model and history?
A: Good resources include:

• The generation pages for E85, E89, and G29. (Wikipedia)
• BMW's own Z Series overview and history.
• Enthusiast communities like Z4-forum.com. (Z4-forum)

Q: How do I check if my BMW Z4 has any open recalls?
A: Use your 17-digit VIN and search it on the official NHTSA recall lookup page or the dedicated VIN recall tool. (NHTSA) This will show any open recalls, including the B48 starter-relay fire-risk recall that affects some 2019-2022 Z4 models. (Car and Driver)

Q: Are there any big safety issues I should know about for newer Z4s?
A: The main widely reported recent issue is the B48 starter-relay fire-risk recall for certain 2019-2022 models. Owners are told to park outside until a new starter is installed. Always check your own VIN for the most accurate, up-to-date information.

Q: Which Z4 accessories are most useful for daily driving?
A: Popular everyday accessories include all-weather floor mats, trunk liners, a car cover, a wind deflector, and smartphone mounts/chargers. These protect the car's interior, keep the cargo area clean, and make top-down driving more enjoyable. (Wikipedia)

Q: How does the current G29 Z4 differ from earlier generations in terms of parts?
A: The G29 uses a soft-top roof again, new B-series turbo engines, and a shared platform with the Toyota Supra, so many mechanical parts are different from the E85/E86 and E89. (Wikipedia) Suspension, electronics, and body components are also redesigned, so parts are not usually interchangeable between generations.

• Car and Driver
• The Sun
• The Sun