Mercedes-Benz E-Class: W211 M272/M273 V6/V8 Balance Shaft Sprocket Plastic Tooth Failure
W211 M272/M273 V6/V8 Balance Shaft Sprocket Plastic Tooth Failure is a very common engine fault on the Mercedes-Benz E-Class on the 2004–2007 cars, and we rate it critical. Putting it right costs $3,500 to $9,000 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 23 documented faults on the Mercedes-Benz E-Class.
- Vehicle
- Mercedes-Benz E-Class
- Engine
- 2.5L / 3.0L / 3.5L / 4.7L / 5.5L
- Years
- 2004–2007
- Fuel
- petrol
- System
- Engine
What you are looking at
No photograph available
What goes wrong
The M272 (3.0/3.5 V6) and M273 (5.0 V8) engines in the W211 E-Class suffer from a widely documented failure of the balance shaft module sprocket. The sprocket uses plastic composite teeth that wear and strip progressively, causing balance shaft desynchronisation from the crankshaft. This results in rough running, timing chain wear, and in advanced cases complete engine destruction. Mercedes faced class action proceedings in Australia over this issue and issued extended warranty coverage. All W211 E-Class petrol models should be considered at risk unless documented repair is verified.
What you would notice
- Rough idle that progressively worsens
- Check engine light with camshaft position or balance shaft correlation codes
- Rattling from engine at idle or low RPM
- Loss of power and increased fuel consumption
How to check it
Where to look. Front of engine block, balance shaft module and drive sprocket within timing chain circuit
This is the highest priority check on any W211 petrol. Scan ECU for camshaft correlation codes and balance shaft faults. Cold-start and listen for timing chain rattle. Check service records for documented balance shaft sprocket replacement — it is a specific, significant repair. Vehicles with absent or unverified history should be treated as unrepaired.
What it costs to put right
$3,500 to $9,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.
Ask the seller
- “Has the balance shaft sprocket been replaced?”
- “Was the Mercedes warranty or service campaign completed for this engine?”
- “Has the engine had any rebuild or timing chain work?”
Now check the Mercedes-Benz E-Class 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.
Where this comes from
Mercedes-Benz E-Class buyer questions
Is w211 m272/m273 v6/v8 balance shaft sprocket plastic tooth failure serious on a Mercedes-Benz E-Class?
We rate it critical and very common on the Mercedes-Benz E-Class. The M272 (3.0/3.5 V6) and M273 (5.0 V8) engines in the W211 E-Class suffer from a widely documented failure of the balance shaft module sprocket. The sprocket uses plastic composite teeth that wear and strip progressively, causing balance shaft desynchronisation from the crankshaft. This results in rough running, timing chain wear, and in advanced cases complete engine destruction. Mercedes faced class action proceedings in Australia over this issue and issued extended warranty coverage. All W211 E-Class petrol models should be considered at risk unless documented repair is verified.
How much does it cost to fix on a Mercedes-Benz E-Class?
$3,500 to $9,000 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 E-Class years are affected?
Our research records this fault on the 2004–2007 Mercedes-Benz E-Class. 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?
This is the highest priority check on any W211 petrol. Scan ECU for camshaft correlation codes and balance shaft faults. Cold-start and listen for timing chain rattle. Check service records for documented balance shaft sprocket replacement — it is a specific, significant repair. Vehicles with absent or unverified history should be treated as unrepaired. Look here: Front of engine block, balance shaft module and drive sprocket within timing chain circuit