Recalls & faults: Mercedes-Benz R230 SL-Class (2002-12)

Recalls: Mercedes-Benz R230 SL-Class

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: Mercedes-Benz R230 SL-Class

• In June 2005, a recall was issued for Mercedes-Benz R230 SL-Class vehicles due to potential faults with certain functions of the Sensotronic Brake Control (SBC) system (PRA 2005/7815).
• In September 2008, a recall was issued for Mercedes-Benz R230 SL-Class models with the Active Body Control (ABC) suspension due to a fault with the front axle body acceleration sensors. Due to an incomplete soldering process during manufacture, certain electrical connection on the circuit boards of the ABC sensors could trigger random sprung mass vibrations at the front axle of the vehicle. This could influence driving stability, operational safety and, in some cases, display a warning message in the instrument cluster (PRA 2008/10321).

Problems and faults: Mercedes-Benz R230 SL-Class

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.

Mercedes-Benz R230 SL 350: M112 V6 crankshaft position sensor

For Mercedes-Benz R230 SL 350 models with M112 V6 engines, the engine may run rough or hesitate due to water entering the crankshaft position sensor; if so, the sensor and wiring assembly require replacement.

2006 Mercedes-Benz R230 SL 350: M272 balancer shaft sprocket gear failure

In May 2011, Mercedes-Benz issued service bulletin LI03.30-P-050027 for Mercedes-Benz R230 SL 350 vehicles that had M272 V6 engines which:

• Had serial numbers prior to 2729..30 468993; and,
• Were manufactured prior to October 2006.

In these vehicles, premature wear of a gear on the balancer shaft sprocket could cause the positioning of the camshafts in the right cylinder bank to be impaired (relative to the crankshaft). According to the service bulletin, this wear of the balancer shaft sprocket could cause the following symptoms:

• Illumination of the check engine light; and,
• Diagnostic trouble codes (DTCs) 1200 or 1208 stored in the ME-SFI control unit.

Owners have experienced failure of the balancer shaft sprocket gear after 95,000 kilometres, accompanied by rough running and illumination of the check engine light. From October 2006 production, a hardened material was used for the sprocket and the timing chain guide wheel (idler) was modified.

For the M272 V6 engine, the repair procedure is as follows:

1. Remove the right front camshaft adjuster cover;
2. Check the balance shaft sprocket for wear using a flexible borescope. In rare cases, a stretched timing chain may be the reason for the DTCs if the sprocket does not exhibit any signs of wear;
3. If worn, replace the balance shaft. Note: since the balancer shaft is located inside the engine block, repairs are expensive;
4. Replace the chain tensioner (part number A272 050 01 11);
5. Change engine oil and filter;
6. Drive with engine at high load and rpm for at least 20 km;
7. Change engine oil and filter once more; and,
8. Replace the camshaft adjustment solenoids.

2006 Mercedes-Benz R230 SL 500: M273 worn timing chain guide gear

In May 2011, Mercedes-Benz issued service bulletin LI03.30-P-050027 for Mercedes-Benz R230 SL 500 vehicles that had M273 V8 engines which:

• Had serial numbers prior to 2739..30 088611; and,
• Were manufactured prior to September 2006.

In these vehicles, a worn guide gear for the timing chain could cause the positioning of the camshafts in the right cylinder bank to be impaired (relative to the crankshaft). According to the service bulletin, this wear of the balancer shaft sprocket could cause the following symptoms:

• Illumination of the check engine light; and,
• Diagnostic trouble codes (DTCs) 1200 or 1208 stored in the ME-SFI control unit.

From September 2006 production, a different material was used for the timing chain guide wheel.

For the M273 V8 engine, the repair procedure is as follows:

1. Remove the right front camshaft adjuster cover;
2. Check the timing chain guide wheel for wear using a flexible borescope;
3. If worn, replace the guide gear (part number A273 050 06 05) of the chain drive;
4. Replace the chain tensioner;
5. Change engine oil and filter;
6. Drive with engine at high load and rpm for at least 20 km;
7. Change engine oil and filter once more; and,
8. Replace the camshaft adjustment solenoids.

2006-08 Mercedes-Benz R230 SL 350 and SL 500: M272 and M273 cam plug oil leaks

Mercedes-Benz M272 V6 and M273 V8 engines that were produced prior to June 2008 may experience oil leaks (or ‘seepage’) from the round plastic expansion plugs (‘cam plugs’) on the back of the cylinder heads. There were two different size cam plugs:

• Part number A000 998 55 90: two small expansion plugs (approximately 2.5 cm diameter); and,
• Part number A000 998 56 90: one large small expansion plug (for engines without vacuum pump).

To fix, the existing plugs were to be removed, the opening cleaned and new plugs fitted; no sealer was to be used in the installation of the new plugs. New cam plugs that were not susceptible to oil leaks were phased into production in June 2008.

Mercedes-Benz R230 SL 350 and SL 500: actuator cam for VIM

For Mercedes-Benz R230 SL 350 (2006-12) and SL 500 (2006-11) vehicles, the plastic actuator cam in the variable intake manifold (VIM) for the M272 V6 and M273 V8 engines is susceptible to failure. Symptoms of a broken actuator cam include:

• Rough idle;
• A loss of power (particularly at low and mid-range engine speeds);
• Illumination of the check engine lights; and,
• Diagnostic Trouble Codes (DTCs) such as P2004, P2005, P2006, P2187 and P2189.

Due to the venting of oil from the PCV (positive crankcase ventilation) system, carbon deposits can accumulate on the swirl flaps inside the variable intake manifold. These carbon deposits increase the resistance on the plastic actuator cam and this can cause it to break. Other parts can also fail as a result, including the swirl flaps, the actuator mounting arms and the vacuum diaphragms.

AustralianCar.Reviews understands that the original equipment supplier for the intake manifold is Pierberg and that Mercedes-Benz’s repair involves replacing the entire intake manifold since they do not supply replacement actuator cams. However, eEuroparts.com sell intake manifold repair kits that replace the plastic actuator cam with a metal component and can be used for DIY repairs. However, the intake manifold also needs to be cleaned as part of any repair. For further information about this problem, please see:

• eEuroparts.com: Fixing Mercedes-Benz Intake Manifold Woes; and,
• eEuroparts.com: Mercedes-Benz Intake Manifold Repair DIY.

Mercedes-Benz R230 SL-Class: other problems and faults

• Under hard acceleration, tapping or knocking noises – like piston slap – may be heard from the engine bay, though it may be that the engine mounts require replacement.
• Banging or thumping noises from the front suspension may be caused by failure of the spring control arm rubber bushing.
• The alternator may not adequately recharge the battery due to a faulty internal voltage regulator.
• The air conditioning (blower) motor may stop working or only work intermittently due to an internal circuit breaker in the air conditioning (blower) motor regulator that requires replacement.
• For early models, the rotors may warp after repeated hard braking; heavier and more heat-resistant rotors were subsequently released.
• The automatic leveling system may allow the vehicle to lower after extended sitting (approx. a week) due to leaking check valve blocks. However, sagging can also be caused by dirty hydraulic fluid, requiring the fluid and filter to be replaced.
• Transmission fluid may leak from the electrical connector on the automatic transmission.
• The battery may be drained by the pneumatic systems continuously running – this may be caused by the ‘keyless go’ or remote boot opening switches sticking.
• The air conditioning compressor may continuously cycle on and off due to a problem in the sensor for the emission control charcoal canister (which sends an incorrect signal to the multiplex bus)
• .Noises from the front suspension may be due to problems with the upper control arms due to torn rubber covers enabling damage to the ball joints.