Top dead center (TDC) of the piston of the first cylinder

Top dead center (TDC) piston, this is the point through which each piston passes when cranking the crankshaft. Each piston reaches TDC at the end of the compression stroke, and then again at the end of the exhaust stroke. In order to set the engine timing mechanism, the TDC of the piston of the first cylinder in the compression stroke is used. Cylinder #1 is on the timing belt side. Remove the negative cable from the battery. Raise the front of the car and secure it on stands. Remove the right front wheel. Unscrew the spark plugs. Remove the drive belt accessory cover to align the timing marks on the crankshaft pulley and cover. Turn the engine with a wrench on the crankshaft pulley clockwise.

There are two marks on the crankshaft pulley. When the crankshaft rotates clockwise, the alignment of the second mark on the pulley with the fixed mark indicates the position of the piston of cylinder No. 1 at TDC. For an approximate installation of the piston of cylinder No. 1 at TDC, you can combine the second mark on the pulley with the straight edge of the oil pan (see fig. 2C.1, 2C.2)





When the marks are aligned, the pistons of cylinders No. 1 and 4 are in the TDC position, and only one of them is in the compression stroke. Remove the head cover and if the cam of cylinder #4 is pointing towards the rear of the car and slightly down, then the piston of cylinder #1 is at TDC on the compression stroke.

After setting the piston of the first cylinder to TDC on the compression stroke, you can set any other piston in series to TDC on the compression stroke by turning the crankshaft 180°clockwise and taking into account the order of operation of the cylinders Install the head covers and toothed belt wheel, lower the car and screw in the spark plugs ignition.