How to Distinguish Between Intake and Exhaust Camshaft Letters?
2 Answers
I stands for intake, E stands for exhaust. Below is a related introduction on how to distinguish between intake and exhaust camshafts: 1. You can differentiate them by looking at the screw position and belt position on the camshaft: The intake camshaft usually has a camshaft position sensor installed at the rear or front, making it longer, or there may be a signal disc at the tail. If you can't tell the difference, it's okay—just make a mark when disassembling, and you can basically identify them. 2. The camshaft is installed at the top of the cylinder head and is responsible for driving the intake and exhaust valves to open and close.
When I first started doing car repairs on my own, I was completely confused about the letter markings on the intake and exhaust camshafts. Later, I discovered that small letters are often engraved at or near the end of the camshaft—usually 'I' for intake (representing intake) and 'E' for exhaust (representing exhaust). The location can also be helpful: the intake camshaft is typically closer to the air filter at the front of the engine, while the exhaust camshaft is oriented toward the exhaust pipe. However, designs vary across different car models, and some compact cars may have less obvious markings, requiring a magnifying glass or phone flashlight for careful inspection. I recommend beginners first check the vehicle manual or search online for the specific model to avoid mistakes. Engine performance heavily depends on this distinction—getting it wrong can lead to power loss, significantly increased fuel consumption, and safety risks. Safety first—don’t rush into repairs if unsure. Consulting a professional shop can save you from unnecessary trouble and make things much easier.
