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Mercedes-Benz ML: M272/M273 Balance Shaft Sprocket Premature Wear

M272/M273 Balance Shaft Sprocket Premature Wear is a very common engine fault on the Mercedes-Benz ML on the 2005–2007 cars, and we rate it critical. Putting it right costs $6,500 to $13,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 10 documented faults on the Mercedes-Benz ML.

Vehicle
Mercedes-Benz ML
Engine
2.5L / 3.0L / 3.5L / 4.7L / 5.5L
Years
2005–2007
Fuel
petrol
Gearbox
auto
System
Engine

This page covers the Mercedes-Benz ML as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mercedes-Benz ML faults10 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Timing chain yet. We would rather show none than show a picture of a different part.

What goes wrong

The M272 V6 and M273 V8 engines used a composite plastic balance shaft idler gear sprocket that wears prematurely. As teeth degrade, the timing chain slackens and the right-bank camshafts fall out of time. A class action lawsuit was settled by Mercedes-Benz in 2011 for approximately USD $4,000 per affected vehicle. Engines with serial numbers below 30468993 on M272 are most commonly affected, though failures outside this range are also documented.

What you would notice

  • Cold-start timing chain rattle lasting more than 2–3 seconds
  • Check engine light with P0016 or P0017 camshaft correlation codes
  • Rough idle or misfire at low RPM
  • Metallic debris or swarf in engine oil

How to check it

Where to look. Timing cover, front of engine

  1. Check engine serial number against the Mercedes published threshold (below 30468993 on M272).

  2. Scan for P0016 and P0017 fault codes.

  3. Listen at cold start for chain rattle lasting more than 2 seconds.

  4. Confirm whether balance shaft sprocket, idler gear, and timing chain have been replaced as a set.

  5. If a workshop inspection is possible: Drain a small oil sample and inspect for metallic swarf.

Parts involved: Timing chain.

What it costs to put right

$6,500 to $13,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

  • “Has the balance shaft sprocket and timing chain been replaced, and can you show a workshop invoice?”
  • “What is the engine serial number?”
  • “Have there ever been check engine lights or stored cam correlation codes?”

Now check the Mercedes-Benz ML you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Mercedes-Benz ML buyer questions

Is m272/m273 balance shaft sprocket premature wear serious on a Mercedes-Benz ML?

We rate it critical and very common on the Mercedes-Benz ML. The M272 V6 and M273 V8 engines used a composite plastic balance shaft idler gear sprocket that wears prematurely. As teeth degrade, the timing chain slackens and the right-bank camshafts fall out of time. A class action lawsuit was settled by Mercedes-Benz in 2011 for approximately USD $4,000 per affected vehicle. Engines with serial numbers below 30468993 on M272 are most commonly affected, though failures outside this range are also documented.

How much does it cost to fix on a Mercedes-Benz ML?

$6,500 to $13,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Mercedes-Benz ML years are affected?

Our research records this fault on the 2005–2007 Mercedes-Benz ML. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Check engine serial number against the Mercedes published threshold (below 30468993 on M272). Scan for P0016 and P0017 fault codes. Listen at cold start for chain rattle lasting more than 2 seconds. Confirm whether balance shaft sprocket, idler gear, and timing chain have been replaced as a set. If a workshop inspection is possible: Drain a small oil sample and inspect for metallic swarf. Look here: Timing cover, front of engine