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Before you buy a used Mercedes-Benz SLC (R172).

2016–2020 · Petrol / Diesel · 3 engines

Taken only from Testigo's sourced sheets. Use it to question the seller and on the test drive: it does not confirm that any particular car is affected.

Mercedes-Benz SLC (R172), real photo of this generation
Mateusmatsuda · CC BY 4.0 · Wikimedia Commons · Photo source

The essentials.

Typical faults by engine

The period and mileage are those mentioned by each sheet's sources. They are not a maintenance interval and do not predict that any particular car will fail.

All versions

Sheets the catalogue links to all 3 of its engines.

  • 9G-Tronic harsh shiftingAutomatic gearbox
    Period mentioned
    2013–2026
    Mileage mentioned
    The sheet does not mention a mileage.

    Applies if: Only if fitted with the automatic gearbox described in the record.

SLC 180 / 200 / 300 (M274)

Petrol

SLC 250 d (OM651)

Diesel

SLC 43 AMG (3.0 V6)

Petrol

We have no faults specific to this engine, only those common to every version.

Which engine has the fewest documented faults?

Documented faults and recalls by engine for the Mercedes-Benz SLC (R172)
EngineDocumented faults
SLC 180 / 200 / 300 (M274)Petrol21 with conditions
SLC 250 d (OM651)Diesel21 with conditions
SLC 43 AMG (3.0 V6)PetrolFewest documented11 with conditions

According to the data we have, the engine with the fewest documented faults is the SLC 43 AMG (3.0 V6) (Petrol).

By fuel, all versions have the same number of documented faults.

We only count the sourced sheets we have. An engine with fewer is not guaranteed to be more reliable: it may have been studied less or sold in smaller numbers.

Official recalls: ask before you pay

We have no official recalls on record for this model. Our list is not complete: ask anyway, with the chassis number.

  1. Ask the seller for the chassis number (VIN): it has 17 characters, appears in the car's documents and can usually also be seen at the base of the windscreen.
  2. Ask an official Mercedes-Benz dealer, or the brand's official website if it lets you check by chassis number, whether each recall has been done or is still outstanding for that VIN.
  3. Manufacturer recalls are normally carried out free of charge by the official service network. If one is outstanding, ask for it to be done before you close the sale.

On the test drive: what to look and listen for

Taken from each sheet's symptoms and checks. You can tick off what you have already looked at: it is saved only in this browser.

0 of 3 checked

Timing / leaks

  • Look out for: Chain rattle on cold starts; engine light with camshaft timing codes (for example P0016 or P001685); oil leaks at the camshaft adjusters; slow coolant loss.

    Ask them to check: Listen to a cold start, read camshaft codes, look for oil on the adjuster magnets and coolant residue at the thermostat. Use Mercedes 229.5 oil.

Timing / injection

  • Look out for: Chain rattle on a cold start; on early units, loud injector knocking; coolant loss from the plastic coolant manifold or the EGR cooler.

    Ask them to check: Listen to a cold start, check the dealer's injector campaign history and check the coolant level.

Automatic gearbox

  • Look out for: Harsh or jerky shifts (especially 1st to 2nd and when cold), vibration, delayed shifts or limp mode; sometimes the gear will not engage from N to D. Codes P073E00 and P07B700.

    Ask them to check: Follow the Mercedes bulletin: reproduce the complaint, save the EEPROM, check the oil level, run the Xentry valve flush, update engine, gearbox and shift unit software and perform the standstill adaptation. If it persists, check the control unit.

OBD codes worth looking for

If they let you read the fault memory with an OBD reader, these are the codes mentioned in this model's sheets:

P0016P073E00P07B700

Sources

Every fact on this page comes from these Testigo sheets and their original sources. Sources are not checked in real time.

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