Recalls & faults: Mercedes-Benz W204 C-Class sedan (2007-14)

Recalls: Mercedes-Benz W204 C-Class sedan

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 W204 C-Class sedan

2006-07 Mercedes-Benz W204 with V6 diesel engine: crankshaft position sensor

In June 2008, a recall was issued for Mercedes-Benz vehicles fitted with the 3.0-litre OM642 V6 turbo-diesel engine that were manufactured between May 2006 and October 2007. In these vehicles, an open circuit in the chip housing of the crankshaft position sensor could occur due to contamination of the silicone during its manufacture. When the problem occurred, the engine would lose all power and not restart. To fix, the crankshaft position sensor was replaced (PRA 2008/10085).

2009-10 Mercedes-Benz W204 C-Class sedan: loss of steering assistance

In November 2010, a recall was issued for Mercedes-Benz W204 C-Class sedan vehicles manufactured between 1 June 2009 and 28 February 2010 for higher than normally required steering forces, particularly during parking manoeuvres. This could be caused by a loss of fluid at the connection between the high-pressure line and the power steering pump – this gradual loss of fluid was generally followed by a whining noise from the pump (PRA 2010/12141).

2009-10 Mercedes-Benz W204 C-Class sedan with diesel engine: diesel fuel leak

In December 2010, a recall was issued for Mercedes-Benz vehicles fitted with the OM651 2.1-litre turbo-diesel four-cylinder engine that were produced between 1 November 2009 and 1 November 2010 due to possible leaking of diesel fuel from the fuel filter (PRA 2010/12193).

2009-11 Mercedes-Benz W204 C 320 CDI and C 350 CDI: diesel fuel leak

In January 2012, a recall was issued for Mercedes-Benz W204 C 320 CDI and C 350 CDI models fitted with the OM642 3.0-litre turbo-diesel engine and manufactured from November 2009 to July 2011. In these vehicles, the fuel filter may leak diesel fuel and pose a potential hazard to other road users (PRA 2012/13002).

2014 Mercedes-Benz W204 C-Class sedan with diesel engine: oil leak

In January 2015, a recall was issued for Mercedes-Benz vehicles with the OM651 turbo-diesel engine that were available for sale during 2014. In these vehicles, the seal ring between the timing chain tensioner and the engine may leak oil – this could result in a hazard for other road users and, in extreme cases, a fire risk (PRA 2015/14509).

2006-08 Mercedes-Benz W204 C-Class sedan: airbag may not work or malfunction

In March 2016, Mercedes-Benz issued a recall for W204 C-Class vehicles that were available for sale from 1 March 2006 to 31 December 2008. Due to the possible corrosion of components in the restraint system control unit, the unit may fail such that the airbags could be deactivated. If the airbags were deactivated, however, the SRS warning lamp would illuminate to warn the driver. In rare cases, various restraint system components could be triggered without any apparent cause – this posed a risk of accident and/or injury (PRA 2016/15280).

2013 Mercedes-Benz W204 C-Class: loss of steering control

In April 2017, a recall was issued for Mercedes-Benz W204 C-Class Sedan vehicles that were manufactured from 1 May 2013 to 31 May 2013. In these vehicles, the bolt which secured the steering coupling may not have been tightened correctly during manufacture. As a result, the steering coupling could detach from the steering shaft – this could cause a loss of steering control, posing a hazard for vehicle occupants and other road users (PRA 2017/16028).

2012-14 Mercedes-Benz W204 C-Class: deployment of driver’s airbag

In February 2018, recall RC2437/A was issued for Mercedes-Benz W204 C-Class vehicles that were available for sale in Australia from March 2012. If the steering column was not sufficiently grounded and the steering column switch was damaged or faulty, an electrostatic discharge could cause the driver’s airbag to deploy. If these conditions occurred, an airbag warning message in the instrument cluster display and a red airbag indicator lamp (signalling that the steering column module was damaged/faulty) would alert the driver. If the airbag deployed in the absence of a collision, it could injure and distract the driver. For the VINs of the recalled vehicles, please see PRA 2018/16572.

2008-11 ‘model year’ Mercedes-Benz W204 C-Class: Takata airbag recall

In May 2018, recall RC2469 S2 was initiated for 2008-11 ‘model year’ Mercedes-Benz W204 C-Class vehicles. In these vehicles, the front airbags contained propellant that could absorb moisture over time. In the event of a collision which triggered the airbag, the airbag could deploy too aggressively and the metal inflator housing could explode/rupture due to excessive internal pressure. If this occurred, metal fragments could be propelled through the airbag cushion and towards vehicle occupants – these fragments posed a risk of serious injury or fatality. For the VINs of the recalled vehicles, please see PRA 2018/16814.

2012 ‘model year’ Mercedes-Benz W204 C-Class Sedan: Takata airbag recall

In October 2018, recall campaign RC2469 S4 was issued for 2012 ‘model year’ Mercedes-Benz W204 C-Class Sedans. These vehicles had Takata passenger airbags and, over time, propellant wafers inside the airbag could absorb moisture. In the event of airbag deployment, excessive pressure inside the metal airbag inflator housing could cause it to explode or rupture, such that metal fragments may be projected through the airbag and into the vehicle’s cabin. These metal fragments had the potential to cause serious injury or fatality. For the VINs of the recalled vehicles, please see PRA 2018/17006.

Problems and faults: Mercedes-Benz W204 C-Class Sedan

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 W204 C 200 Kompressor, C 200 CGI, C 200 and C 250: camshaft adjuster/sprocket failure

Background
For the M271 and M271 EVO engines, each camshaft has a camshaft adjuster/sprocket mounted to the front of it. The camshaft adjuster is mounted on a bearing so that it can rotate separately from the camshaft and is driven by timing chain. Furthermore, a solenoid is bolted onto the camshaft adjuster and attached to the end of the camshaft. As the camshaft adjuster is rotated by the timing chain, the sprocket can control the offset of the camshaft.

While camshaft adjuster failures are a recognised problem for the M271 engine, there have also been reports for the M271 EVO engine. For the post-2009 M271 EVO engine, however, it is understood that Mercedes-Benz changed the design of the camshaft adjuster, the aluminium cover for the camshaft adjuster and solenoid for the 2012 model year. As such, post-2012 M271 EVO engines should not experience this problem.

Camshaft adjuster/sprocket failure
The camshaft adjuster for the M271 engine is made from cast iron and its operation against the single-row steel timing chain causes the teeth to wear prematurely; while the teeth can potentially break off, this is relatively rare. Wear to the camshaft adjuster can cause:

• The engine’s valve timing to be advanced or retarded;
• The timing chain to stretch; and,
• At worst, changes to engine timing can cause the pistons and valves to collide – such engine damage is extremely serious.

Merc271 provides re-manufactured camshaft adjusters in which the original gear face has been removed and a high-tensile, surface hardened steel gear profile has been applied to make it significantly stronger. Some owners, however, recommend replacing the timing chains and camshaft adjusters as a preventative measure every 130,000 kilometres.

Symptoms
Symptoms of camshaft adjuster failure include:

• A rattling noise on start-up caused by play of the timing chain and camshaft adjuster teeth;
• Uneven running and a rough idle;
• Diagnostic trouble codes (DTCs) related to camshaft timing.

Replacement
Replacing the camshaft adjuster requires:

• The solenoid and valve cover to be removed;
• The tension on the timing chain to be released; and,
• The camshaft adjuster to be removed from the camshaft.

Mercedes-Benz W204 C 200 CDI and C 220 CDI: leaking diesel injectors

For the Mercedes-Benz W204 C-Class’ OM646 diesel engines (in the C 200 CDI and C 220 CDI), the injector seal is a copper washer that is susceptible to failure. Failure of the injector seal causes fuel to leak from the cylinder head and symptoms of a leaking injector include:

• A fuel smell (like paraffin oil) inside the passenger compartment;
• A ‘chuffing’ sound from the top of the affected cylinder as combustion gas escapes on the compression stroke;
• A black, shiny ‘coal like’ deposit around the leaking injector or injectors (sometimes referred to as ‘black death’);
• A loss of power; and,
• Increased fuel consumption.

To fix, the engine covers have to be removed to determine which injector(s) are leaking. If carbon deposits are present, they have to be completely cleared and chipped away with a blunt screwdriver/scraper and vacuumed. Furthermore, if an unclamped injector cannot be moved freely by hand, it may have seized. If seized, the injector needs to be removed by a specialist as damage to the injector or head can result in significantly higher repair costs. The injector seat will likely be blackened and carbonised – this needs to be cleaned off; in severe cases, it may need to be re-cut to provide a usable sealing surface.

For further information, please see Mercedes Diesel Injector Advice.

Mercedes-Benz W204 C 200 CDI and C 250 CDI: OM651 injector failure and timing chain/tensioner wear

For the OM651 turbo-diesel engine, the Delphi piezo injectors that were fitted for the 125kW to 150kW variants (i.e. the W204 C 220 CDI BlueEfficiency and C 250 CDI BlueEfficiency) experienced a high failure rate, generally occurring beyond 50,000 kilometres. If the injectors failed, the engine warning light would illuminate, the vehicle would enter ‘limp home’ mode and the engine run unevenly. Initially, revised piezo injectors were introduced. Subsequently, however, Mercedes-Benz initiated a customer service action whereby the original Delphi piezo injectors were replaced with magnetic solenoid injectors, a new ECU was installed, a fuel return line was retrofitted and the engine cover was changed. From around mid-2012, Mercedes-Benz ceased using piezo injectors for these engines and used magnetically-actuated solenoid injectors instead.

There have been reports of wear of the simplex timing chain and/or chain tensioner at higher mileages. Since the chain is installed on the transmission side of the engine, access is restricted and replacement is expensive.

Mercedes-Benz W204 C 320 CDI and C 350 CDI: OM642 engine

• Pre-2010 OM642 engines were susceptible to oil cooler leaks due to heat-related seal degradation. In 2010, Mercedes-Benz introduced more durable Viton seals which could be identified by their purple colour (the previously used seals were orange).
• The TWC temperature sensor (part no. A005 153 40 28) was susceptible to failure and was subsequently replaced with part no. A007 153 74 28. When the temperature sensor fails, the check engine light may illuminate and issue the OBD-2 diagnostic code P2031.
• The positive crankcase ventilation system vents to the inlet of the turbocharger. However, the vented air may contain too much oil to easily pass through the swirl motor valves which are downstream of the turbocharger. Once this oil and sludge begins to accumulate, the swirl motor valves may become inoperative and blow a fuse that controls other sensors which are required for the engine and emissions systems to operate properly. As a result, the vehicle will enter ‘limp home’ mode and limit engine speed to 3000 rpm.

Mercedes-Benz W204 C 280 and C 300: actuator cam for VIM

For 2007-09 Mercedes-Benz W204 C 280 and 2010-14 Mercedes-Benz W204 C 300 vehicles, the actuator cam for the variable intake manifold (VIM) in the M272 V6 engine 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 W204 C 320 CDI and C 350 CDI: knocking or ticking noise at idle

In February 2013, Mercedes-Benz issued Service Bulletin LI03.20-P-048278 for Mercedes-Benz W204 C-Class vehicles that that had 3.0-litre OM642 diesel engines – this included the C 320 CDI, C 350 CDI and C 350 CDI BlueEfficiency.

According to LI03.20-P-048278, these vehicles may exhibit an intermittent knocking or ticking noise at idle and at engine speeds up to 1500 rpm. Specifically,

• The noise would occur after a mileage of approximately 32,000 kilometres or after an oil change;
• The noise could be clearly heard in the area of the first crankshaft main bearing;
• The noise would not be present when the poly-V belt was removed;
• The noise was a pulse-like crackling that occurred at irregular intervals; and,
• 20 pulses (ticking) represented a ‘justifiable complaint’.

These symptoms were attributed to a ‘run-in effect’ or defect of the first crankshaft main bearing shells. To verify the complaint, the poly-V belt was to be removed to see if that eliminated the noise. To fix, the bearing shells of the first crankshaft main bearing were to be replaced.

Problems and faults: Mercedes-Benz W204 C-Class sedan

• The engine may not restart after it has been running (i.e. heat soak), but restart once cooled; this may be due to a faulty control unit for the fuel pump.
• Knocking noises from the engine bay during low speed manoeuvres such as parking may be due to problems with the hydro bushings; improved bushings were subsequently released.
• A low oil warning when the oil level is sufficient may be due to a faulty oil level switch or software error.
• The sunroof may not close automatically due to a faulty control module (located in the overhead console); if so, the control needs to be re-flashed.
• The climate control air conditioning may not function properly if snow enters through the cowl; a revised cowl was subsequently released and could be retro-fitted.