Used BMW X3/X4 (G01/G02) review

Exterior:

• If you’re not absolutely set on having a sunroof, it’s best to avoid one. Owners have reported a range of issues, from rattles and malfunctioning open/close mechanisms to outright leaks. While clogged drainage channels are often blamed, some sunroofs still leak even when completely clear—particularly in heavy rain. Given BMW’s engineering standards, this is something they really should have accounted for.
• However, those aren’t even the worst sunroof-related problems. Certain models were subject to legal action over allegedly defective sunroofs that were prone to shattering. In some cases, normal body flex appears to cause stress on the glass, leading to spontaneous breakage. While not all vehicles will experience this, it’s a concern worth being aware of.
• Water ingress isn’t limited to the sunroof either. The fin antenna seal tends to wear prematurely, particularly in hot climates, allowing water to seep into the interior. More on the headaches this causes in the interior section below.
• Early models also suffered from powered tailgate failures. Some refused to open, others stopped midway, and a few owners even reported cases where the tailgate unexpectedly dropped.
• For the Australian market, the LCI update brought LED headlights as standard, which is great—unless they fail outside of warranty. Pre-LCI models with LED headlights sometimes experience condensation buildup inside the housing. Fixing this typically requires a complete headlight assembly replacement, which owners report costs over $4000 per unit—before labour. Since replacing the headlight involves removing the entire front bumper, expect a hefty bill if a BMW dealership is involved.
• Speaking of which, many owners strongly advise against BMW dealerships for non-warranty repairs. Independent mechanics are often better, cheaper, and more transparent with their work.
• Another common issue reported by owners is central locking failures. Sometimes the doors won’t lock or unlock using the key fob, which can be caused by faulty actuators, degraded wiring, or a malfunctioning central locking control unit. In some cases, it’s a simple fix; in others, it’s far more complex and expensive.
• Grille shutters, designed for aerodynamic efficiency, are another weak point. Failures are often caused by sensor malfunctions, wiring corrosion, or debris buildup. While the concept is clever, fragile plastic components and intricate electronics in a front-facing position don’t exactly lend themselves to longevity.
• As is typical of European cars, BMW’s brake pads produce excessive brake dust, coating the wheels almost instantly. While regular cleaning helps, many owners opt for aftermarket brake kits, which not only reduce dust but also offer improved performance and longevity at a lower cost than BMW’s OEM replacements.

Interior:

• Some owners report squeaky front seat bases and rattling dashboards—annoying but usually straightforward to fix.
• Early iDrive systems had frequent Bluetooth and CarPlay connectivity dropouts, though most were resolved via software updates.
• The wireless charging pad can often be slow to charge and often overheats, causing phones to shut off mid-charge.
• Climate control systems have their own set of problems. The blower motor is known to fail prematurely, though replacing it is relatively simple. Some vehicles suffer from fluctuating temperatures or vents that only blow cold air. Some issues can be resolved through software updates, but others require expensive HVAC system repairs that can run into the thousands.
• Now for a truly ridiculous design flaw: the TCB module (responsible for emergency calls and GPS) has a rechargeable battery that depletes over time. BMW, in their infinite wisdom, placed this module under the roof lining. To replace the battery—an inexpensive $50 part—you must remove the side pillar trims and roof lining. Owners who have had this done report labour costs exceeding $2000, and in some cases, more than $3000.
• To make matters worse, a failing fin antenna seal (mentioned earlier) can allow water into the roof cavity, frying the TCB module. This means some owners have paid thousands to replace the battery, only to have the entire module fail shortly after due to water damage—forcing them to go through the whole process again.
• Some vehicles also suffer from TCB module malfunctions, causing them to randomly place emergency calls to BMW’s call centre. When this happens, the call must be manually terminated, rendering the infotainment system unusable for several minutes—an infuriating issue if it happens repeatedly.
• Instrument cluster problems have been reported as well. Some owners have experienced malfunctioning gauges, persistent warning lights for non-existent issues, and even complete cluster failures. In some cases, reprogramming fixes the issue; in others, the entire cluster must be replaced.
• The indicator stalks? It seems they sometimes just stop working altogether.
• Additionally, early models sometimes “forget” keys that haven’t been used in a while, requiring them to be re-coded. BMW dealerships have been known to overcharge for this service, so push back if they try to gouge you.

Mechanically:

BMW has moved towards modular engine designs, meaning the 4 and 6-cylinder engines share numerous components—including their common problems.

Petrol Engines:

• The PCV valve is a known weak point. Unlike many cars where you can replace just the valve or diaphragm, in the X3/X4, you must replace the entire valve cover. This involves removing the high-pressure fuel pump and fuel injectors, and reinstalling the injectors requires a special tool to fit the Teflon seals. Failures tend to occur around the 100,000 km mark.
• The oil filter housing is another notorious issue. It can leak both coolant and oil—externally or internally. Internal leaks can lead to oil/coolant cross-contamination, which can cause catastrophic engine damage. Failures typically begin around 80,000 km.
• The heat management module (BMW’s high-tech alternative to a traditional thermostat) is another trouble spot. With multiple rotary valves, servo-style actuators, and numerous seals, it’s a complex unit with a high likelihood of failure from around 150,000 km.
• Much of the cooling system, including bypass pipes and expansion tanks, is plastic—prone to cracking and leaks. Expect to replace these components at around 100,000 km.
• Other common failures include purge valves and VANOS sprockets. The latter can break internally, triggering camshaft angular offset or correlation fault codes. Some owners have mistakenly replaced the timing chain when the real issue was the sprockets. Given that timing chains are located at the rear of the engine (requiring engine or transmission removal for replacement), this is an expensive mistake to make.

Diesel Engines:

• These use a single-turbo setup and, so far, have been relatively reliable.
• They lack Valvetronic, which simplifies things slightly.
• Harmonic balancer failures can occur, though they aren’t overly common.
• The intake manifold is prone to carbon buildup, which can cause actuator and linkage failures—something increasingly common in modern diesel engines.
• Routine maintenance includes cleaning the MAP sensor at every service and keeping an eye on the EGR system and DPF, as failures are not uncommon.
• Boost pipe leaks often lead to DPF issues as well.

Maintenance and Servicing:

• BMW’s condition-based and extended service intervals should be completely ignored. These intervals are a major contributor to premature failures and long-term reliability issues. Instead, service the car every 10,000 km or every 12 months—whichever comes first.
• Extended service intervals are, in our opinion, a deliberate strategy to keep cars running just long enough to reach the end of the warranty period. This keeps initial ownership costs lower, making new models more appealing, while pushing expensive long-term problems onto second-hand owners.
• Automakers love to promote fuel efficiency and emissions compliance, but if they truly cared about sustainability, they’d build cars designed to last—not ones that are crippled by poor maintenance policies within five years. Extended service intervals ruin engines and turn otherwise solid cars into money pits.