BMW 2.5i
Balanced six-cylinder with 192 hp and silky-smooth running. Cooling system components (water pump, thermostat, expansion tank) are the most common wear items.
Balanced six-cylinder roadster
The 192 hp of the M54B25 combines six-cylinder silkiness with real shove. In the light Z3 a perfect balance between refined cruiser and sports car — open cockpit, rear-wheel drive, R6 sound. The balance is just right.
Engine Weaknesses 6
The DISA variable intake valve breaks at the shaft base or the membrane tears. Fragments can be sucked into the engine and cause catastrophic damage.
Symptoms: Power loss in the lower rev range, rattling or clattering from the intake area, in the worst case engine damage from ingested fragments.
The Behr/Mahle electric coolant thermostat fails prematurely. Failure causes overheating or permanent cold running with increased fuel consumption.
Symptoms: Engine does not reach operating temperature or overheats quickly, poor heater output.
The plastic membrane in the crankcase ventilation system typically tears at 120,000–150,000 km. Result: air leaks, oil enters the intake tract, increased oil consumption and rough running.
Symptoms: Rough idle; slight exhaust smoke; increased oil consumption; "puff" when opening the oil filler cap; air-leak fault codes
The expansion tank, thermostat housing, and water pump impeller — all plastic — become brittle from around 100,000 km. Sudden coolant loss leading to overheating is possible.
Symptoms: Coolant loss with no visible source; fluctuating temperature gauge; steam from the engine bay; expansion tank can burst without warning
The rectangular gasket between the oil filter housing and the engine block fails regularly. BMW part number 11421719855 — aftermarket gaskets tend to have a shorter service life.
Symptoms: Oil seeping below the oil filter, oil smell when engine is hot.
The rubber seals in the double-VANOS unit wear from around 100,000 km. Reduced torque in the lower rev range and a slight increase in fuel consumption are typical results.
Symptoms: Noticeable torque loss below 3,000 rpm; hesitation when pulling away; occasional VANOS fault codes (P1519, P1520); engine noise on cold start
Vehicle Weaknesses 6
The fabric hood tears from years of folding and UV exposure and becomes leaky. Door seals also fail with age. The plastic rear window turns cloudy or develops folds.
Control arms, tie rod ends and ball joints on the front axle wear with higher mileage and are flagged at inspection. Typical issue on all E36-based vehicles.
The barrel bearings at the Z3 rear axle wear at higher mileage and must be replaced. An inexpensive repair that causes no consequential damage if done in time.
The VANOS unit on the six-cylinder engines (M52, M54) is prone to leaks and malfunctions. Worn seals and seized pistons in the VANOS system cause power loss and rough running.
The body-coloured mirror base rusts early on the Z3 and develops blisters. In severe cases the mirror can break off. Inexpensive fibreglass replacement bases are available.
Electric window regulators fail more frequently on the Z3. Cables or guide rails break, motors wear out. Typical age-related issue for late 1990s vehicles.