KNOWN FAULTS · BMW

Known faults for the BMW Z3 (E36/7).

2000–2002 · Petrol

Sources are not verified in real time and no entry confirms that your car is affected.

4 known faults with sources

Engines: 1.9 / 2.0 / 2.2 / 2.8 / 3.0 (Petrol)

Applies if: Only six-cylinder 2.0, 2.2, 2.8 and 3.0 (M52TU/M54); not the 1.9.

Plastic cooling-system parts (M52TU / M54)Cooling

Engine / equipment: M52TU and M54 six-cylinder petrol (320i–330i E46, 520i–530i E39, 520i–530i E60 up to 2005, X3 2.5i/3.0i, X5 3.0i, six-cylinder Z3 and Z4)
Period mentioned: 1998–2006
Symptoms: Coolant loss without an obvious puddle, sweet smell, low-level warning, steam in the engine bay, heater stops warming and the temperature needle rises. Expansion tank failure is usually sudden; the water pump can fail with no visible leak.
Possible cause described: Many cooling parts are plastic and become brittle with heat and age: expansion tank, radiator neck, thermostat housing and the water pump impeller, which can crack or come off its shaft and stop pumping. The electric auxiliary pump is also a frequent failure.
Check for the garage: With the engine cold, check the level and look for cracks or dried coolant on the tank, radiator neck and thermostat housing. At a garage: pressure-test the system and inspect the pump. If the temperature rises, stop somewhere safe: a single overheat can warp the aluminium head. Never open the system hot.
Cost cited in the source: No verifiable estimate in the sources; ask for a quote. The sources recommend replacing tank, pump (preferably with a metal impeller), thermostat and hoses together on high-mileage engines.A rough figure from the original database, not an up-to-date quote.

Engines: 1.9 / 2.0 / 2.2 / 2.8 / 3.0 (Petrol)

Applies if: Only six-cylinder 2.0, 2.2, 2.8 and 3.0 (M52TU/M54); not the 1.9.

Crankcase ventilation (CCV) valve on the M52TU / M54Intake / engine management

Engine / equipment: M52TU and M54 six-cylinder petrol (320i–330i E46, 520i–530i E39, 520i–530i E60 up to 2005, X3 2.5i/3.0i, X5 3.0i, six-cylinder Z3 and Z4)
Period mentioned: 1998–2006
Symptoms: High oil consumption, bluish smoke, rough idle, whistling from a vacuum leak, engine light with lean-mixture codes and very strong suction when trying to remove the oil filler cap at idle.
Possible cause described: The system has a regulating valve and four plastic and rubber hoses under the intake manifold. The valve membrane tears and the hoses crack; on short trips in cold weather, condensation mixes with the oil, blocks the return through the dipstick tube and can freeze. Several forum owners cut oil consumption sharply by renewing the system, though others also blame piston ring wear.
Check for the garage: At a garage: smoke-test the intake to find leaks (CCV hoses, intake boots, DISA valve seal, valve cover gasket) and check whether the dipstick tube return is blocked. A cold-climate version of the system exists for cold regions.
Cost cited in the source: No verifiable estimate in the sources; ask for a quote. It is labour-intensive because the intake has to be removed.A rough figure from the original database, not an up-to-date quote.

Engines: 1.9 / 2.0 / 2.2 / 2.8 / 3.0 (Petrol)

Applies if: Only six-cylinder 2.0, 2.2, 2.8 and 3.0 (M52TU/M54); not the 1.9.

Double VANOS seals (M52TU / M54)Timing system

Engine / equipment: M52TU and M54 six-cylinder petrol with double VANOS (320i–330i E46, 520i–530i E39, 520i–530i E60 up to 2005, X3 2.5i/3.0i, X5 3.0i, six-cylinder Z3 and Z4)
Period mentioned: 1998–2006
Symptoms: Loss of torque and pull below about 3,000 rpm, louder or unsteady idle, the engine bogs when the air conditioning is switched on and sometimes VANOS fault codes. On 1998–2000 M52TU engines, jolts or stalling on cold starts.
Possible cause described: VANOS varies intake and exhaust timing with two hydraulic pistons. The O-rings on those pistons lose elasticity and flatten, oil leaks past them and the system cannot reach the requested position. According to the repair-kit maker, remanufactured units use the same original seals.
Check for the garage: Read the engine codes and, at a garage, compare actual and requested camshaft positions in live data. Rule out vacuum leaks and the CCV first, as they cause similar symptoms. On M52TU engines with cold jolts, the kit maker describes a test with the intake VANOS solenoid unplugged.
Cost cited in the source: Seal kit: about $60 in parts according to its maker (US price), plus gasket and washers; labour extra.A rough figure from the original database, not an up-to-date quote.

Engines: Z3 M (S50 / S54, 3.2) (Petrol)

BMW M rod bearings (S54, S65, S85)Engine (rod bearings)

Engine / equipment: S54 (M3 E46, Z4 M), S65 V8 (M3 E90/E92/E93) and S85 V10 (M5 E60, M6 E63)
Period mentioned: 2000–2013
Symptoms: Little prior warning; once wear is advanced, a metallic rod knock that rises with revs. On the S65 and S85, also jerking and limp mode from failing throttle actuators.
Possible cause described: Very tight rod bearing clearances and soft bearing material, made worse by cold oil, revving the engine before it is warm and poor maintenance. Catastrophic failure is rare, but premature wear is common.
Check for the garage: Oil analysis and bearing replacement history. Indicative preventive replacement: S54 around 130,000–160,000 km, S65 around 100,000–130,000 km and S85 around 80,000–110,000 km.
Cost cited in the source: Preventive replacement: approx. €2,800–5,500 (converted from dollars); a spun bearing costs far moreA rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: 80,000–160,000 km. This is not a maintenance interval and does not predict a failure.