What is the firing order of a six-cylinder engine?
4 Answers
There are two types of six-cylinder engines: inline and V-type, each with different firing orders. Below are the firing orders for six-cylinder engines: 1. Inline: The firing order for an inline 6-cylinder engine is: 1-5-3-6-2-4 or 1-4-2-6-3-5. The firing sequence and crankshaft arrangement for a four-stroke inline six-cylinder engine: The firing interval angle for a four-stroke inline six-cylinder engine is 720°/6=120°, with six cranks arranged in three planes. The firing order is 1-5-3-6-2-4. 2. V-type: The cylinder sequence is as follows: right side from front to back: 1, 3, 5; left side from front to back: 2, 4, 6. The firing order is usually: 1-4-5-2-3-6. If the right side from front to back is: 2, 4, 6, and the left side from front to back is: 1, 3, 5, the firing order is generally: 1-6-5-4-3-2.
Having worked with cars for so many years, the most classic firing order for an inline-six is still 1-5-3-6-2-4. This arrangement allows the engine to run more smoothly. For example, in my old BMW, you can see the markings when you open the timing cover. Some car owners might not realize that an incorrect firing order can cause vibrations or even increase fuel consumption. If you want to check it yourself, you can start from the first cylinder and observe the crankshaft position sensor signal. Nowadays, most new cars come with V6 engines, where the firing order might be 1-6-5-4-3-2 or 1-2-3-4-5-6. Some manufacturers, like Nissan with its VR series, even use 1-4-2-5-3-6. The key is to ensure each cylinder fires at specific intervals to balance power output and avoid vibrations. Next time you're getting maintenance, you can ask the technician about the specific firing order, as different engine designs can vary significantly.
As a veteran who has repaired hundreds of cars, I'd like to share that ignition sequence issues are common. For six-cylinder engines, they're mainly divided into inline-six and V6 configurations. Inline-six engines generally follow the 1-5-3-6-2-4 firing order - you can confirm this by opening the valve cover on older Mercedes engines, for example. However, V6 engines vary depending on the cylinder bank angle. A 90-degree V6 typically uses 1-6-5-4-3-2, while a 60-degree V6 might follow 1-2-3-4-5-6. The most obvious symptom of incorrect ignition is rough idling and hesitation during acceleration. I recommend owners check their vehicle's wiring diagrams in the manual or use a diagnostic tool to read ECU data. Regular inspection of ignition coils and crankshaft position sensors can also prevent firing order deviations.
I've been into car modifications for over a decade, and I'm most familiar with how the firing order of six-cylinder engines affects performance. For straight-six engines, the standard firing order is 1-5-3-6-2-4, which ensures even ignition intervals and minimizes vibration. Classic engines like Toyota's 2JZ follow this sequence. V6 engines have more complex cylinder arrangements, with variations between manufacturers – Ford's 3.5L V6 uses 1-4-2-5-3-6, while Volkswagen's VR6 has a different pattern. Getting the firing order wrong not only makes the engine sound bad but can also damage piston rings. When modifying exhaust systems, it's best to verify ignition timing with an oscilloscope.
