Recalls & faults: BMW E85 Z4 Roadster (2003-09)

Recalls: BMW E85 Z4 Roadster

Overview

Manufacturers, or importers, issue recalls for defects or faults which have the potential to cause injury. Generally, manufacturers will inform the original buyers if their vehicle is subject to a recall and of the steps required to remedy the defect or fault. Please note that the recalls below (if any) are for Australian-delivered vehicles only. Furthermore, the number of recalls should not be taken as an indication of a model’s reliability or its safety more generally.

Recalls: BMW E85 Z4 Roadster

No recall information is available for the BMW E85 Z4 Roadster. To search for recalls of BMW models, please visit Product Safety Recalls Australia: BMW.

Problems and faults: BMW E85 Z4 Roadster

Overview

This section identifies potential problems, causes and fixes based on the experiences of owners and repairers, online sources and technical service bulletins. This information is provided solely for reference purposes and AustralianCar.Reviews recommends that only properly qualified persons carry out repairs or modifications. Furthermore, the number of items below should not be taken as an indicator of a model’s reliability or the frequency with which they may occur.

To report a problem or fault to the AustralianCar.Reviews team, please use the Contact Us form. Note that AustralianCar.Reviews does not offer advice on automotive problems or disputes; such enquiries will not receive a reply. For vehicles purchased from dealers after 1 January 2011, please see our Australian Consumer Law fact sheet.

BMW E85 Z4 Roadster: roof motor and hydraulic pipe failure

For the BMW E85 Z4 Roadster, the drain pockets for the roof can become blocked by leak matter, roof moss and atmospheric dirt which washes off the roof. If this occurs, the drain pockets fill with water, causing:

• The electric roof motor to be submerged in water;
• The hydraulic pipes to corrode and rupture – this may be detected by the presence of clear oil near the roof;
• The overflow from the drain pockets to flow into the chassis members (behind the seat and seatbelt areas). This water can then
  • Enter the cabin and drip onto the carpets behind the seats;
  • Enter the airbag satellite B-pillar modules; and,
  • Accumulate inside the sills.

If water enters the cabin, it may be heard sloshing backwards and forwards until a plastic jacking pad is removed so that the trapped water can drain out.

If the drain pockets for the roof cannot be cleared with compressed air, rods or a borescope, the roof assembly should be removed so that a screwdriver can be used to break through the blockage. Once the blockage is cleared, it is recommended that the drains be tested with a hose to make sure that water drains properly – it should flow out a hole in front of the rear wheels.

BMW Z4 Roadster 2.5i and 3.0i: M54 VANOS failure

For the M54 engine, the VANOS units may fail due to deterioration of the VANOS piston seal O-rings which are made from Buna (a material with limited temperature resistance). Over time, the O-rings harden and shrink, causing them to lose their functional characteristics – this can cause symptoms such as a loss of power below 3000 rpm, surging around 3000 rpm, a louder idle and rough running.

The piston O-rings lies under and provides support to a Teflon piston seal ring. Replacing the O-rings requires the Teflon seals to be removed for access. Since the Teflon seals cannot be removed from the piston seal groove without damaging it, the Teflon and O-ring seals must be replaced simultaneously. For greater longevity, the Buna O-rings can be replaced with O-rings made from Viton.

The VANOS unit had two piston seals with O-rings, while each piston had two O-ring sizes to provide hydraulic sealing in two VANOS cylinders of different sizes and an additional, smaller O-ring that was used to seal off a piston bearing. It is understood that the O-ring for this cap was also made from Buna and deteriorated in the same manner as the piston seal O-rings.

For more information about the M54 engine, please see BMW M54 and S54 engines.

E85 Z4 2.5si and 3.0si (N52): ticking noise from camshaft lifters

In September 2009, BMW issued technical service bulletin SI B11 09 07for E85 Z4 2.5si and 3.0si Roadsters with N52 engines that were produced prior to 31 November 2008. In these vehicles, an occasional ticking or rattling noise from the camshaft hydraulic lifters (HVA) may occur during cold engine starts. It is understood that the ticking was caused by an insufficient quantity of air-free oil for the HVA elements. To fix, however, the twelve (12) exhaust camshaft hydraulic valve lifters needed to be replaced (part no. 11 33 7 605 330).

A revised cylinder head was phased into production from 1 October 2008 and fully implemented on 31 November 2008, as per the following casting numbers –

• N51 (B30): 7588277.01;
• N52 (B30): 7588273.01; and,
• N52K (B30): 7588271.01.

E85 Z4: M54, N52, N52K and S54 engine deposits

In February 2008, BMW issued technical service bulletin SI B 13 01 07 for E85 Z4 Roadsters with M54, N52 or N52K engines, and E85 Z4 M Roadsters with S54 engines. In these vehicles, deposits in the injection and induction system may cause driveability complaints and the ‘Service Engine Soon’ light to be illuminated. This condition could be caused by:

• Deposits at the fuel injector’s tip which affected fuel flow and the air/fuel mixture ratio. Symptoms included hesitation or stumble during acceleration or loss of power; poor fuel efficiency; increased HC and CO emissions; and, the ‘Service Engine Soon’ lamp to illuminate due to misfire faults;
• Carbon deposits at the valves and on the intake manifold ports absorbing fuel during the warm-up phase, causing a leaner air/fuel mixture. Carbon deposits (or build-up) could also disturb the mixture flow at low throttle conditions and/or idle speeds. Symptoms of carbon deposits included a loss of power; unstable and/or rough idle; increased HC, CO and NOx emissions; and, the ‘Service Engine Soon’ lamp to illuminate due to intermittent misfire faults; and,
• Combustion Chamber Deposit Interference (CCDI) when there was contact between carbon deposits on the piston crown and the cylinder head. The noise created by this contact may be misdiagnosed as a ping, knock or other mechanical failure. CCDI occurs first as a cold start noise that can fade as the engine reaches operating temperature. As deposits build, there is an increase in compression temperature that may cause pre-ignition detonations. Symptoms include knocking, pining, poor acceleration, increased NOx emissions and engine idle speed surges.

Z4 Roadster 2.5i and 3.0i: M54 oil leaks

For models with the 2.5- and 3.0-litre inline six cylinder M54 engines, oil may leak from the cylinder head or valve cover gasket and into the No. 2 spark plug due to porosity of the engine head casting. As such, the head casting needs to be replaced.

Z4 Roadster 2.5i and 3.0i: M54 engine and cold climates

In February 2009, BMW issued technical service bulletin SI B11 08 03 for BMW E85 Z4 Roadsters with the M54 engine. In these vehicles, extremely cold climate conditions could cause moisture to accumulate and freeze in the:

• Engine oil separator;
• Hose to oil dipstick guide tube; or,
• Orifice in the dipstick guide tube.

Depending on the position of the crankcase ventilation valve when this occurred, the following may occur:

• High crankcase pressures (stuck closed) resulting in valve cover leakage and/or breakage; or,
• An oil hydro-lock condition (stuck open) which could result in engine damage.

To fix, the crankcase ventilation valve, hoses and dipstick guide hoses were to be replaced; a new insulated style of oil separator and hoses were also introduced.

E85 Z4: N51/N52/N54 VANOS faults

In October 2010, BMW issued technical service bulletin SI B11 02 08 for E85 Z4 Roadsters with N52 engines produced from January 2006.In these vehicles, the ‘Service Engine Soon’ (MIL) lamp may illuminate and be accompanied by a reduction in engine performance/performance; this may occur after driving with the engine at normal operating temperature. If the ignition is cycled, the engine then usually performs normally. Furthermore, the following fault codes are stored in the DME:

• 2A82 VANOS intake – stiff; jammed mechanically;
• 2A87 VANOS exhaust – stiff; jammed mechanically; or,
• 3100 Boost-pressure control, deactivation – boost pressure build up prohibited (N54 engine only).

These VANOS faults may be caused by insufficient oil pressure supply to the inlet VANOS adjustment unit. To effectively move the camshafts to the target positions in the specified time and under all engine conditions, sufficient oil pressure supply to the VANOS control pistons was required. When engine operation required that the VANOS quickly advance or retard the intake or exhaust camshaft, fault 2A82 or 2A87 may occur if the camshaft is ‘late’ or does not reach the target position. In this situation, engine power may be reduced and a check control message be displayed.

According to the service bulletin, a mechanical restriction or electrical failure of the VANOS solenoid and/or the electrical circuit could cause insufficient oil supply to the VANOS assemblies.

Depending on the diagnosis, both VANOS solenoids may need to be replaced (as well as the engine oil and filter). If there was excessive wear to the camshaft bearing ledge, the camshaft hook ring seals and the affected camshaft bearing ledge would require replacement.

E85 Z4: ZF transmission sealing sleeve seepage

In March 2010, BMW issued technical service bulletin SI B 24 08 06 for BMW E85 Z4 vehicles with ZF six-speed 6HP19/21 or 6HP26/28 transmissions that were manufactured up to April 2008. In these vehicles, transmission fluid seepage may be visible in the area of the transmission oil pan; the service bulletin attributed this condition to the tightness of the Mechatronic sealing sleeve’s O-ring. Only if a visible leakage trace indicated a substantial loss of transmission fluid was the Mechatronic sealing sleeve (part no. 24 34 7 588 725) to be replaced.

Z4 M Roadster: S54 engine

• Connecting rod bearing wear: the connecting rod bearings can wear prematurely and, ultimately, fail – this occurs because of insufficient rod bearing clearance which, in turn, results in inadequate oil lubrication between the crank journal and the road bearing;
• VANOS failure: the VANOS unit has an oil pump disc with two holes and the exhaust hub has two driver tabs that insert into the oil pump disc holes. Due to excessive rotational pressure force or rattling/hitting force, one or both of the driver tabs can break – if this occurs, VANOS malfunction and engine fault codes will be issued. A broken tab can stay lodged in the VANOS oil pump disc hole or it can drop to the oil pan. In rare cases, the tab can engage the chain and sprockets, causing engine damage;
• VANOS solenoid failure: the VANOS solenoid coil pack may fail due to cracked solder joints which are the connector pins on the PCB (printed circuit board); and,
• VANOS rattle.

For more information on the S54 engine, please see BMW M54 and S54 Engines.

E85 Z4 M Roadster: rear differential grinding noise

In January 2009, BMW issued technical service bulletin SI B33 01 02 for E85 Z4 M Roadsters. In these vehicles, a grinding noise may be heard from the rear differential during slow cornering; the noise was most prevalent during turning manoeuvres with a high degree of lock such as parallel parking or tight circles.

When cornering, a ‘slip stick’ effect was created on the lining and steel discs incorporated in the differential locking clutch, thereby causing the grinding noise. The noise typically dissipated as the locking clutch discs in the differential were ‘broken in’. The break-in time, however, varied according to driving habits.

For the E46 M3, E90/E92/E93 M3, E60 M5 and E63/E64 M6, a specially formulated differential oil (part number 83 22 2 282 583) was recommended.

Problems and faults: BMW E85 Z4 Roadster

• If a battery charger is connected directly to the battery, it can trigger an error on vehicles fitted with the intelligent battery sensor; battery chargers should be connected to the terminal under the bonnet, not the battery itself.
• The ‘check engine’ light may illuminate and the engine may run rough due to defective ignition coils, although only BRMEI coils – not Bosch – were affected.
• Erroneous ‘low oil’ warnings may appear when the engine is shut down due to a faulty sensor.
• If the key is left in the ignition overnight, the battery may be drained and the vehicle may fail to start.
• The key may not remotely unlock the doors – this is usually due to a lack of use of the key, particularly the spare key, as the vehicle recharges the battery.
• In cold conditions, the telematics system may stop working and the battery may discharge due to the telematics control unit (TCU) entering the wrong mode.