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Mercedes-Benz R-Class R 350 CDI BlueTec 4Matic common faults.

2006–2010, MPV, diesel, 210 HP.

The fault list covers: OM642DE30LA engine, MB7229 transmission.

What you save stays on this device only. My saves

6 fault write-ups. All are important. 6 recalls.

If you know the year, pick it. Faults for other years drop out of the list.

Before you buy

Known faults

6 important faults

critical1

OM642 V6 diesel: the swirl flap and its plastic linkage break

critical

The swirl flaps sit in the intake of both cylinder banks, and a central electric actuator moves them through a linkage. Soot builds up on the linkage and on the flaps, the flap starts to bind, and in the end the plastic breaks. This is the most frequent single failure on this engine, and the broken pieces can get into the engine, which can lead to engine damage. The symptoms are the engine warning light, rough running and a lack of power, with the code P2004 or P2005 in the fault memory. The condition of the flaps can be seen with an endoscope through the intake, without dismantling. It is worth looking above 150,000 km, especially on the W164 ML320 and ML350 CDI. An aluminium repair kit is available for it, which lasts longer than the factory part.

above 100,000 km

What to check

  • Read the fault memory and look for the P2004 and P2005 codes
  • Ask whether the flaps have been inspected with an endoscope, because they are visible without dismantling
  • At low revs watch for a lack of power and rough running
2 more steps in the write-up

expensive5

7G-Tronic (722.9): mechatronics and conductor plate

expensive

In the Mercedes 7 speed 722.9 automatic (7G-Tronic / 7G-Tronic Plus) the mechatronics unit and the conductor plate (Leiterplatte) age over time: jerking on shifts, delayed engagement, a "Getriebe schützen" message, and fault codes on the gearbox electronics.

Show the rest

The repair is typically replacing the mechatronics unit or the conductor plate together with an oil change: not the whole gearbox. The complaint is most common on the longitudinal platforms from around 2005 to 2015 (C/E/ML and the early GLC).

The 9G-Tronic (725.0) is a different design; this applies only to the 7G.

between 100,000 and 220,000 km

What to check

  • Try it cold and warm: a delayed 1 to 2 or 2 to 3 shift is suspect
  • Watch for the gearbox warning or the "Getriebe schützen" message on the dash
  • Ask for a fault code read on the gearbox controller (not just the engine codes)
1 more steps in the write-up

Airmatic air suspension: leaking air spring, overworked compressor

expensive

The Mercedes Airmatic system holds the ride height with air springs and electronically controlled dampers. The most common faults over time are the relay, the compressor and a leaking air spring or air line.

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The rear air springs of the 2003 to 2009 E-Class (W211) are particularly prone to leaking along the clamps. If the system leaks, the compressor runs continuously, overheats and fails, so an unrepaired leak takes the compressor with it.

Symptoms: one corner of the car sinks by morning, an "Air Suspension" or level control fault message, and compressor noise while standing. It was an option (or standard) across several generations from the W220 S-Class onwards; the estate E-Class often has air springs with level control on the rear axle as standard.

between 100,000 and 220,000 km

What to check

  • In the morning, before setting off, look at all four corners: an uneven stance means a suspected leak
  • With the car standing, listen to the compressor: continuous running indicates it is overworked
  • Ask for a fault code read on the suspension controller (level and pressure sensor codes of the C1132 / C1144 kind)
3 more steps in the write-up

OM642 V6 diesel: leaking oil cooler seals in the engine valley

expensive

The oil cooler sits in the V between the cylinder banks, and its seal becomes porous over the years. The leak is characteristic: there is no visible trace on the outer sides of the engine, because the oil collects in the V under the intake and drips down from there. A smaller oil puddle can therefore appear under the car, while the place of the leak cannot be found from outside. As the fault gets worse, oil can also get into the coolant, and that shows up as oily streaks in the expansion tank. It gives no fault code. The repair is expensive because the cooler can only be reached after removing the intake and the swirl flap actuator. In a specialist workshop it can run up to 2,000 euro. The fault comes up above 120,000 km. One thing is worth asking even after the repair. If the V is not cleaned out thoroughly, the remains of the old seal and the soot get into the oil circuit, and there they can ruin the bearings and the oil passages as well.

above 120,000 kmup to 2,000 EUR

What to check

  • Look at the expansion tank: an oily streak means oil in the coolant
  • Look for an oil puddle under the car, but do not look for the leak on the side of the engine
  • Shine a light under the intake, between the cylinder banks, where the oil collects
2 more steps in the write-up

OM642 V6 diesel: the injector shaft soots up and it starts hard when cold

expensive

Combustion gases escape past the shaft of the Bosch piezo injector, and soot builds up around the shaft. The symptoms are a hard, rough cold start and a rough idle. The engine has six injectors, so finding the faulty one is more work as well. The quantity correction values of the control unit have to be read per injector, and this is worth doing before anyone replaces all of them. A cleaning additive and better quality fuel help to prevent the sooting. The fault comes up above 120,000 km. The high-pressure system of the same engine (Bosch CP3) can also give starting trouble and a lack of power at high mileage, so the diagnosis separates the two.

above 120,000 km

What to check

  • Start the engine cold and watch whether it starts hard or roughly
  • At idle watch for rough running
  • Ask for the quantity correction to be read per injector, not for a general fault code list
2 more steps in the write-up

OM642 V6 diesel: defeat devices, KBA 009147, threat of an operating ban

expensive

The maker issued recalls and voluntary service actions for the six cylinder OM642 diesel, aimed at defeat devices (Abschalteinrichtungen) in the engine control software.

Show the rest

According to the German technical press the KBA 009147 recall is dated 12 August 2019; at the maker it carries the codes 5496121 and 5496142. The ADAC names two affected groups: E 350 BlueTEC / E 350 d (only the C 207 coupe), 02.2013 to 12.2016, and G 350 d (possibly G 350 BlueTEC), 09.2015 to 12.2015.

Felix Domke uncovered eight defeat devices affecting the SCR catalyst or the exhaust gas recirculation.

In summer 2023 it was reported that the KBA in Flensburg and the federal transport ministry were threatening part of the OM642 diesel fleet with a ban on further operation.

When buying outside Germany this mainly concerns the 2011 to 2016 V6 diesels exported out of the German market (ML/GLE 350, E 350, S 350, GL, Viano). Only the franchised dealer can tell you by VIN whether the update was done.

What to check

  • Ask by VIN whether KBA 009147 (maker codes 5496121 / 5496142) applies to the car, and whether it was carried out
  • On an imported car ask for the German service history and the recall confirmation
  • Check whether it is a C 207 coupe (E 350 BlueTEC / E 350 d): the ADAC list names only the coupe in the 02.2013 to 12.2016 window
2 more steps in the write-up

Checklist

Mercedes-Benz R-Class R 350 CDI BlueTec 4Matic

First what you would check on any car. Then the faults of this model.

Before you buy

Checklist

The printed sheet starts with what you would check on any car. What you tick stays on this device only.

On every car

Ask the owner

Faults of this model

vinkodex.com · Before you buy it, see what can go wrong.

Official recall6 recallsShow

The manufacturer fixes these for free at a franchised dealer. Ask with the VIN whether it was done.

Most recent: 26 April 2024

24V298000SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUMSERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM26 April 2024 · NHTSA (USA)

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2006-2012 ML, GL, and R-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. Moisture may accumulate and cause corrosion in the brake booster housing unit, which can result in reduced brake performance or brake failure.

Risk: Reduced brake performance or brake failure can increase the risk of a crash.

Remedy: Owners are advised not to drive their vehicles until the remedy has been performed. Dealers will remove the rubber sleeve, inspect the brake booster, and as necessary, replace the brake booster. All repairs will be performed free of charge. Owner notification letters were mailed on May 24, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MMUSA's number for this recall is 2024050001/2. This recall is an expansion of previous recall number 22V-315.

We could not check this: model year. The authority's notice

22V315000SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUMSERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM9 May 2022 · NHTSA (USA)

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2006-2012 ML-Class, GL-Class, and R-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. Moisture may accumulate and cause corrosion in the brake booster housing unit, which can result in reduced brake performance or brake failure.

Risk: Reduced brake performance or brake failure can increase the risk of a crash.

Remedy: Owners are advised not to drive their vehicles until the remedy has been performed. Dealers will remove the rubber sleeve, inspect the brake booster, and as necessary, replace the brake booster. All repairs will be performed free of charge. Owner notification letters were mailed June 30, 2022. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's numbers for this recall are 2022050014, 2022050015 2022090006, & 2022090007.

We could not check this: model year. The authority's notice

A12/0083/17Safety recallInjuriesno date · EU Safety Gate

The axle screws on the front/rear axle may not have been correctly secured which could lead to an overload on the remaining screw connections on the axle concerned. This overload may result in the rupture of the screws and under certain conditions, in loss of control over the vehicle.

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: Unknown

We could not check this: model year. The authority's notice

A12/00830/22Safety recallInjuriesno date · EU Safety Gate

Severe corrosion may lead to a leakage of the brake booster, thus reducing the braking force, leading to an increase in brake pedal force required to decelerate the vehicle, resulting in a possible increase in stopping distance. Moreover, due to severe corrosion, a particularly strong or severe braking manoeuvre may cause mechanical damage to the brake booster, preventing the vehicle from decelerating through the service brake and thus increasing the risk of an accident. The product does not comply with the requirements laid down in the Regulation on the approval and market surveillance of motor vehicles and their trailers, and of systems, components and separate technical units intended for such vehicles.

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: Unknown

We could not check this: model year. The authority's notice

A12/0121/18Safety recallInjuriesno date · EU Safety Gate

The sport seats and the roll bar are not compatible. There may be contact between the headrest and the roll bar in the event of an accident.

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: Unknown

We could not check this: model year. The authority's notice

A12/01236/20Safety recallInjuriesno date · EU Safety Gate

The driver and passenger airbags of the company Takata in vehicles with ammonium nitrate gas generators without drying agents could, under certain climate conditions, lead over time to a chemical change in the fuel. In the event of an accident triggering the release of the driver or passenger airbag, this change could cause the gas generators to burst. If a gas generator ruptures, the airbag would then have no restraining function and loose parts from the gas generator could reach the vehicle interior. This would increase the risk of injury for passengers.

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: Unknown

We could not check this: model year. The authority's notice

Engine and transmission

OM642DE30LA · Viano 3.0 CDI

140–173 kW (190–235 HP) · diesel

MB7229 · 7G-Tronic / 7G-Tronic Plus, longitudinal (Mercedes 722.9 / NAG2)

automatic · 7 speed

Torque limit700 Nm
MakerMercedes-Benz

We built the code from the model and the gear count. The factory sheet does not state it.

Variant data

What is in this version

Factory data

Trim
R 350 CDI BlueTec 4Matic
Body
MPV
Fuel
diesel
Transmission
automatic
Engine size
2987 cc
Power
155 kW (211 HP)
Drive
AWD
Production
2006–2010

Factory service interval

The manufacturer specifies this for this version. Of the mileage and the time, the one that comes first is the one that counts.

  • Air filter

    • 60,000 km or 4 years

  • Cabin (pollen) filter

    • 30,000 km or 2 years

  • Brake fluid change

    • first: 3 years, then 2 years(first change at 3 years, then every two years)

  • Fuel filter, diesel

    • 60,000 km or 2 years
All W251 versions

Information, not an expert opinion

We write the descriptions, and we put the source next to them. A person reviews them before they go out. They are still information, not a technical expert opinion.

  • A fault on the list does not mean the car you are looking at has it.
  • A fault missing from the list does not mean the model is fault-free. Write-ups are made model by model. Not all of them are done.
  • You decide whether to buy. This is no substitute for an inspection. That needs a workshop and a history check.
Details in the terms