The M272 V6 fires in the sequence 1-4-2-5-3-6. This arrangement alternates between the left and right cylinder banks to maintain smooth operation and even firing.
Engine layout and cylinder numbering
The M272 is a 3.0-liter V6 used in a range of Mercedes-Benz models from the mid-2000s onward. Cylinder numbering follows the common Mercedes convention: left bank (driver side) is cylinders 1–3, right bank (passenger side) is cylinders 4–6. The front-most cylinder on the left bank is typically 1, with numbers increasing toward the rear; the right bank starts at 4 near the front and runs to 6 at the rear.
Firing order and arrangement
To illustrate the ignition sequence, the following order is used by the M272 across the six cylinders. The pattern alternates between the two banks to maintain balance and smoothness.
- 1
- 4
- 2
- 5
- 3
- 6
The sequence ensures even spacing between ignition events (every 120 crank degrees) and proper balance between the two banks of cylinders.
Why the firing order matters
Correct firing order is crucial for engine smoothness, power delivery, and preventing misfires. A mismatched ignition sequence can lead to rough running, reduced performance, or potential damage over time if not addressed.
How to verify the firing order on your M272-powered vehicle
Before attempting verification or maintenance, consult the official service manual for your model year, as small variations can exist between engines in different markets.
- Identify the cylinder numbering on your engine: left bank 1–3, right bank 4–6.
- Locate the ignition coil/plug wiring order or consult the factory wiring diagram to confirm the sequence 1-4-2-5-3-6.
- With the engine at top dead center on cylinder 1 (TDC 1), verify that the coil-on-plug arrangement aligns with the corresponding cylinders in the firing order.
- Use a timing tool or a strobe timing light if your model has timing marks, following the vehicle’s service manual instructions.
- Double-check with the vehicle’s documentation to confirm the exact order for your chassis and year.
Ensuring the correct order in the coil-to-cylinder mapping is essential, especially if you are replacing spark plugs or ignition coils yourself.
Summary
The M272 V6 uses a firing order of 1-4-2-5-3-6, alternating between the left (1–3) and right (4–6) banks for even firing and smooth operation. Always verify against the specific model year documentation when performing maintenance or part replacements.
What firing order is 1 8 4 3 6 5 7 2?
The LS engines number the same but changed the firing order. Because of the popularity and longevity of Chevrolet V8 engines, the 1-8-4-3-6-5-7-2 firing order is the one almost every gearhead learns first. These engines came with distributors that spin clockwise, so that's also a useful reference.
What is the firing order of a 1956 Ford 272?
1956 Ford 100 272 V8 Firing Order Explained
The firing order for the 1956 Ford 100 with a 272 V8 2bbl engine is 1-5-4-2-6-3-7-8. To troubleshoot misfires, inspect spark plugs, ignition wires, and distributor cap for wear or damage.
What is the firing order of the Mercedes M272 engine?
Figure 4 illustrates the firing orders for a 6-cylinder engine with firing order 1-4-3-6-2-5. This is the firing order on the Mercedes Benz M272-E35 engine which has powered ML350 vehicles since 2006. It also powers the R350 vehicle and other Mercedes Benz vehicles.
Is cylinder 1 at the front or back?
In a straight engine the cylinders are numbered from front (#1 cylinder) to rear.