Note: The position of the piston of the 1st cylinder in the compression stroke can be determined by feeling the compression in the spark plug hole, and then aligning the marks on the crankshaft/camshaft pulley.
Top dead center (TDC) is the highest position in the cylinder that each piston reaches as it moves up and down as the crankshaft rotates. Every piston reaches TDC on the compression stroke and then again on the exhaust stroke, but TDC usually refers to the piston's position on the compression stroke.
Setting the piston to TDC is an important part of many processes such as removing camshafts and timing chains.
- Before starting the process, make sure that the transmission (CVT) is in neutral position. Apply the parking brake or block the rear wheels. Turn off the ignition system.
- Remove the spark plugs.
- Raise the front of the vehicle and support it on stands.
- Remove the screws and the protective cover under the engine to gain access to the crankshaft pulley bolt. On some models, the bolt can be accessed through a small window in the casing.
- There are alignment marks on the pulley crown that align with the pointer.
Note: The TDC mark is a recess in the form of an unpainted line.
- Turn the crankshaft clockwise using a socket or open-end wrench on the pulley bolt head (if you look from the front) until the mark on the crankshaft pulley crown (B) is aligned with the TDC indicator (A).
With this position of the crankshaft, the piston of the 1st cylinder is at TDC.
Note: To determine the compression stroke, place your finger over the spark plug hole in the first cylinder while turning the crankshaft. Compression pressure should be felt (in this position all valves of the 1st cylinder are closed).