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Mercedes-Benz C-Class C 300 de AMG Line common faults.

2021–, saloon, diesel, 197 HP.

The fault list covers: M139E20DEHLA, OM654M engine, MB7250 transmission.

What you save stays on this device only. My saves

2 fault write-ups. Both are important. 17 recalls.

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

Before you buy

Known faults

2 important faults

critical1

On the OM654 and OM656 diesels the maker started a recall over the vacuum controlled coolant pump (maker action code: 2090008). The fault: a leak can develop between the coolant and the vacuum circuit; if coolant reaches the electric switching valves, an electrochemical reaction can raise the temperature of the part, and a fire risk cannot be ruled out.

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The fix: replacing the electric switching valve and a software update. The campaign started at the end of 2021; the affected group is the C-Class, E-Class and other OM654/OM656 models.

A recall on the model does not mean it was carried out on this car. Only the franchised dealer can tell you, by VIN.

What to check

  • Ask the franchised dealer by VIN: is action 2090008 OPEN or CLOSED
  • Check the coolant level and look around the vacuum system for leaks
  • Ask for the service sheet: a switching valve replacement plus a software update is part of the campaign
1 more steps in the write-up

expensive1

The modern OM654 four cylinder diesel (and the modular OM656 six cylinder) carries two weaknesses on the used market that reinforce each other.

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1) Roller finger followers (Rollenschlepphebel). According to the German technical press, on some cars the followers wear early at around 100,000 to 120,000 km. On 10 July 2018 the maker introduced a strengthened follower from engine number 80278367 (new part number A6540505701 in place of the old A6540501100). On early built cars the risk is higher. A faulty follower develops so much heat that the removed metal shows blue discolouration (Anlaufspur).

2) Oil dilution. The post injection needed to regenerate the particulate filter puts diesel fuel into the engine oil. With short urban use the engine does not get warm enough, the fuel does not evaporate, the oil thins out, and the follower and valvetrain are exactly what suffers most from poor lubrication.

The timing chain sits on the gearbox side: if it stretches, the replacement is labour intensive. There are few complaints of a broken chain, but on the early series about 5,000 cars were recalled for a weak chain, and the Tritan 15 coating was changed to Tritan 18.

between 80,000 and 160,000 km

What to check

  • Listen to the engine on a cold start: metallic ticking or rattling from the follower or the chain is suspect
  • Ask for the engine number: cars below 80278367 (before July 2018) are the old follower group
  • Check the service book: how often and with what oil (MB 229.52 is recommended) it was changed. Long intervals plus urban use is the worst pairing
2 more steps in the write-up

Checklist

Mercedes-Benz C-Class C 300 de AMG Line

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

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

Official recall17 recallsShow

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

A12/00045/22Safety recallFireno date · EU Safety Gate

The vacuum-controlled coolant pump may not be tightly sealed between the coolant and vacuum circuits. This may result in the coolant leaking into the vacuum circuit leading to an electrochemical reaction, increasing the risk of fire. 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

The authority's notice

A12/00055/22Safety recallElectric shock, Fireno date · EU Safety Gate

Due to an incorrect material composition of the Mode 2 charging cable for charging at a household power socket, the insulation resistance of the rubber buffer could be impaired, overriding the protective function of the charging cable. Furthermore, in combination with an error in the household infrastructure, the activation of the protective device in the household electrical circuit might be prevented. This could cause the user to have an electrical shock and could lead to a fire. 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

The authority's notice

A12/00147/22Safety recallInjuriesno date · EU Safety Gate

The cupholder in the centre armrest of the second seat row may become detached from the armrest in the event of an accident. This could increased the risk of injury to occupants of the vehicle. 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

The authority's notice

A12/00440/23Safety recallInjuriesno date · EU Safety Gate

Improper foam used in the front bumper may cause the active hood release to fail to deploy in the event of a collision with a pedestrian, increasing the risk of injury. The product does not comply with 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

The authority's notice

A12/00732/22Safety recallInjuriesno date · EU Safety Gate

An erroneous notch in the impact absorber may lead to failure of the tube sensor for the actuation of the active hood. In case of an accident, the active hood for pedestrian protection might be lifted too late or not at all, increasing the risk of injury to the pedestrian involved. The product does not comply with 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

The authority's notice

A12/00791/23Safety recallInjuriesno date · EU Safety Gate

The airbag control unit may be faulty, resulting in that the PRE-SAFE function and/or the active bonnet are not activated as intended, increasing the risk of injury in case of an accident. The product does not comply with 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

The authority's notice

A12/00888/21Safety recallInjuriesno date · EU Safety Gate

The rear head rests might not have been attached correctly. As a result, they could become displaced or detached from the seat in the event of an accident, increasing the risk of injury.

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

The authority's notice

A12/01347/22Safety recallInjuriesno date · EU Safety Gate

Improper tyre pressure label in the tank cap may result in the tyre pressure not being identified based on the vehicle load and thus the vehicle operating with insufficient tyre pressure. As a result, the tyre may be damaged, increasing the risk of an accident. The product does not comply with 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

The authority's notice

A12/01511/22Safety recallInjuriesno date · EU Safety Gate

Improperly connected layers of the windscreen could lead to its delamination in the event of an accident. Moreover, glass splinters could break free and impair the support of the passenger airbag. The product does not comply with 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

The authority's notice

A12/01532/21Safety recallInjuriesno date · EU Safety Gate

The belt tensioner arm may have been manufactured with a borderline tolerance, which could cause one side of the V-ribbed belt to rub against the belt tensioner, causing it to fail. As a result, the coolant pump may stop working, causing the engine to overheat, thus compromising the impermeability of the oil sump. Consequently, oil may leak onto the road, posing a risk to the following traffic. 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

The authority's notice

A12/01707/22Safety recallInjuriesno date · EU Safety Gate

The gearbox may be faulty. Forces and vibrations may occur when driving, which could damage the gear-shift linkage and the gearbox could disconnect from the drive shaft, causing the vehicle to lose propulsion. Moreover, components could detach from the vehicle, posing a risk to other road users. The product does not comply with 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

The authority's notice

A12/01767/23Safety recallFireno date · EU Safety Gate

The tightening torque on the screw connections on certain 12V and 48V ground points may be insufficient. This may lead to improper wiring fixation, which may cause rise of temperature in this area, increasing the risk of fire. The product does not comply with 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

The authority's notice

A12/01786/21Safety recallInjuriesno date · EU Safety Gate

In some cases the end mount of the seat belt on the driver’s seat may not have been fitted in accordance with the specifications, for this case the end mount of the seat belt would be held in position only by the external seat trim. In the event of adverse conditions or an accident this could seriously impair the restraining function of the seat belt and increase the risk of injury to the driver. 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

The authority's notice

A12/01841/24Safety recallFire, Injuriesno date · EU Safety Gate

The incorrect connection of a wiring harness to the pre-fuse box can cause a failure and increased electrical resistance. This can lead to a sudden loss of propulsion, which increases the risk of accidents and injuries. Moreover, this can increase the risk of fire in the vehicle. The product does not comply with 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

The authority's notice

A12/02217/23Safety recallFireno date · EU Safety Gate

Faulty welding between the fuel tank and the filler pipe can cause a fuel leak, creating a risk of fire. The product does not comply with 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

The authority's notice

SR/00633/25Safety recallFireno date · EU Safety Gate

Ground-cable bolts may not have been tightened with sufficient torque. This can lead the wiring harness not to be properly secured and result in an increase of the connection's electrical resistance. The temperature can rise in this area, increasing the risk of fire. The product does not comply with 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

The authority's notice

SR/01846/25Safety recallInjuriesno date · EU Safety Gate

The safety cap on the end mount of the seat belt of the passenger seat may not be correctly installed. The safety cap could become detached over the life of the vehicle, and the belt would no longer be fixed in its anchorage. In the event of abrupt deceleration or in the event of an accident, the belt may no longer have a restraining effect, thereby increasing the risk of accident/injury. The product does not comply with 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

The authority's notice

Engine and transmission

2 engines · 1 transmissions

M139E20DEHLA

10–350 kW (14–476 HP) · petrol

MB7250 · 9G-Tronic, longitudinal (Mercedes 725.0 / NAG3)

automatic · 9 speed

Torque limit700 Nm
MakerMercedes-Benz

We built the code from the model and the gear count. The factory sheet does not state it. More than one engine code is possible. The fault list shows the faults of each.

Variant data

What is in this version

Factory data

Trim
C 300 de AMG Line
Body
saloon
Fuel
diesel
Transmission
automatic
Engine size
1993 cc
Power
145 kW (197 HP)
Drive
RWD
Production
2021–

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)
  • Spark plugs, petrol

    • 60,000 km or 6 years

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