Align the crankshaft drivebelt pulley notch (arrowed) with the 0 (zero) on the timing cover

Top Dead Centre

(TDC) for number one piston

- locating

1 Top Dead Centre (TDC) is the highest point in the cylinder that each piston reaches as it travels up the cylinder bore. Each piston reaches TDC on the compression stroke and again on the exhaust stroke, but TDC generally refers to piston position on the compression stroke.

2 Positioning the piston(s) at TDC is an essential part of many procedures such as camshaft and timing belt/chain/pulley removal, and distributor (where applicable) removal.

Engine in-car repair procedures 2A•5

3 Before beginning this procedure, be sure to place the transmission in Neutral and apply the handbrake or block the rear wheels. Remove the spark plugs (see Chapter 1).

4 In order to bring any piston to TDC, the crankshaft must be turned using the method outlined below. When looking at the timing belt/chain end of the engine, normal crankshaft rotation is clockwise. Turn the crankshaft with a socket and ratchet attached to the bolt threaded into the front of the crankshaft. Apply pressure on the bolt in a clockwise direction only. Never turn the bolt anti-clockwise.

5 Remove the cylinder head cover as described in Section 4.

6 Turn the crankshaft until the notch in the crankshaft pulley is aligned with the 0 on the timing cover (see illustration).

7 Look at the camshaft lobes for No 1 cylinder. Both the intake and exhaust camshaft lobes should be pointing away from the camshaft followers. If they are not, use the socket/spanner to rotate the crankshaft one complete revolution

(360°) - now the lobes should be pointing away from the followers. Additionally, on 1.3 litre 4E-FE and 1.6 litre 4A-FE engines, the mark on the No 1 camshaft bearing cap should be visible through the hole in the camshaft sprocket (see illustration). On 1.4 litre 4ZZ-FE and 1.6 litre3ZZ-FE VVT-i engines, the reference marks on the intake and exhaust camshaft sprockets should be aligned with the top of the cylinder head (see illustration).

8 After the number one piston has been positioned at TDC on the compression stroke, TDC for any of the remaining pistons can be

Дата добавления: 2014-12-23