MajorCommonEngine

Mercedes-Benz E-Class: OM651 diesel timing chain stretch (W212)

OM651 diesel timing chain stretch (W212) is a common engine fault on the Mercedes-Benz E-Class on the 2009–2016 cars, and we rate it major. Putting it right costs ≈A$2,300 to ≈A$4,600 at independent workshop rates, shown as an approximate guide in Australian dollars. 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 26 documented faults on the Mercedes-Benz E-Class.

Vehicle: Mercedes-Benz E-Class
Engine: 2.1L
Years: 2009–2016
Fuel: diesel
System: Engine

This page covers the Mercedes-Benz E-Class 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 E-Class faults26 documented faults on this model

What you are looking at

What goes wrong

The 2.1 OM651 diesel (E200/E220/E250 CDI) can stretch its timing chain and wear the guides from around 120,000 km. The chain also drives the high-pressure fuel pump, so a stretched chain throws camshaft/crankshaft correlation codes and, in the worst case, can jump a tooth and cause major damage. Early engines had tensioner issues acknowledged by Mercedes. Listen for a rattle on cold start and after an oil change.

What you would notice

Rattle on cold start or briefly after an oil change
Rough running or misfire
Camshaft/crankshaft correlation fault codes
Loss of power / limp mode

How to check it

Where to look. Timing chain at the rear (transmission) side of the engine

Insist on a genuine cold start and listen at the front of the engine for a chain rattle. Ask whether the chain has been replaced and at what kilometres. Have any correlation codes scanned before purchase on a high-km car.

Parts involved: Timing chain.

What it costs to put right

≈A$2,300 to ≈A$4,600 at independent workshop rates, shown as an approximate guide in Australian dollars. That is for this job on its own, not for the car.

An estimate, converted to Australian dollars, 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 timing chain been replaced, and at what kilometres?”
“Any rattle on the first cold start of the day?”

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 still has money owing on it, has been written off or reported stolen, what kms it showed in past sale ads, whether it has had accident repair claims and what it is worth today. That comes from the official records for that plate. Enter the plate and its state for the A$17.90 Vehicle Check, or the full history from A$24.99.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

en.mercedesassistance.com OM651 engine workshop guide
speedme.ru Mercedes OM651 diesel common problems

Mercedes-Benz E-Class buyer questions

Is om651 diesel timing chain stretch (w212) serious on a Mercedes-Benz E-Class?

We rate it major and common on the Mercedes-Benz E-Class. The 2.1 OM651 diesel (E200/E220/E250 CDI) can stretch its timing chain and wear the guides from around 120,000 km. The chain also drives the high-pressure fuel pump, so a stretched chain throws camshaft/crankshaft correlation codes and, in the worst case, can jump a tooth and cause major damage. Early engines had tensioner issues acknowledged by Mercedes. Listen for a rattle on cold start and after an oil change.

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

≈A$2,300 to ≈A$4,600 at independent workshop rates, shown as an approximate guide in Australian dollars. 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 2009–2016 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.