Valve Clearance Inspection And Adjustment
note

Inspect and adjust the valve clearance when the engine is cold (Engine coolant temperature : 20°C) and cylinder head is installed on the cylinder block.

1.

Remove the cylinder head cover.

2.

Set the piston of No.1 cylinder to the TDC (top dead center) on compression stroke.

(1)

Turn the crankshaft pulley clockwise and align its groove with the timing mark of the timing chain cover.

note

Do not rotate engine counterclockwise.

(2)

Check that the TDC marks of the intake CVVT sprocket and exhaust camshaft sprocket are in straight line on the cylinder head surface as shown in the illustration.

note

If not, turn the crankshaft one revolution (360°). (Do not rotate engine counterclockwise.)

(3)

Mark on the timing chain links corresponding to the timing marks of the intake CVVT sprocket and exhaust camshaft sprocket.

3.

Inspect the valve clearance.

Valve clearance

Intake :

0.17 ~ 0.23 mm (0.0067 ~ 0.0091 in.)

Exhaust :

0.25 ~ 0.31 mm (0.0098 ~ 0.0122 in.)

(1)

Check only the intake valves of the 1st and 2nd cylinders and exhaust valves of the 1st and 3rd cylinders for their clearance.

A.

Using a thickness gauge, measure the clearance between the tappet and the base circle of camshaft.

B.

Record the out-of-specification valve clearance measurements. They will be used later to determine the required tappet for adjusting.

Valve clearance specification (Engine coolant temperature : 20°C [68°F])

(2)

Turn the crankshaft pulley one revolution (clockwise 360°) and align its groove with timing mark of the timing chain cover.

(3)

Check the intake valves of the 3rd and 4th cylinders and exhaust valves of the 2nd and 4th cylinders for their clearance.

4.

Adjust the intake and exhaust valve clearance.

(1)

Remove the front camshaft bearing cap (A) and the exhaust camshaft bearing caps (B).

(2)

Remove the service hole bolt (A) on the timing chain cover.

(3)

Release the ratchet (A) of the timing chain tensioner by pushing and holding the ratchet upward using a thin rod (B).

(4)

Loosen the timing chain by pushing the tensioner arm using a handy bar (A).

(5)

Remove the exhaust camshaft (A).

(6)

Remove the intake camshaft bearings (A) then remove the intake camshaft (B).

caution

To hold the timing chain, tie it with strap.

(7)

Remove the tappet(s) in out-of-specification valve clearance from the cylinder head.

(8)

Measure the thickness of the removed tappet using a micrometer.

(9)

Calculate the thickness of a new tappet so that the valve clearance comes within the specificified value.

Intake : N = T + [A - 0.20 mm (0.0079 in.)]

Exhaust : N = T + [A - 0.28 mm (0.0110 in.)]

N : Thickness of new tappet

T : Thickness of removed tappet

A : Measured valve clearance

(10)

Select a new tappet with a thickness as close as possible to the calculated value.

caution

Tappets are available in 41 size increments of 0.015 mm (0.0006 in.) from 3.000 mm (0.1181 in.) to 3.600 mm (0.1417in.).

(11)

Place a new tappet on the cylinder head.

(12)

Install the intake and exhaust camshafts.

(Refer to Cylinder Head Assembly - "Camshaft")

(13)

Recheck the valve clearance.

(14)

Place the intake camshaft (B) and install the intake camshaft bearings (A).

Tightening torque :

11.8 ~ 13.7 N.m (1.2 ~ 1.4 kgf.m, 8.7 ~ 10.1 lb-ft)

(15)

Place the exhaust camshaft (A) with aligning the corresponding timing chain (painted link) up on the each sprocket.

note

The timing marks of each sprocket should be matched with the timing marks (painted link) of timing chain when installing the timing chain.

(16)

Release the ratchet (A) of the timing chain tensioner by pushing and holding the ratchet upward using a thin rod (B).

(17)

To place the exhaust camshaft on the cylinder head properly, loosen the timing chain by pushing the tensioner arm using a handy bar (A).

note

Be careful not to damage the camshaft and the cylinder head journal bore when placing the camshaft.

(18)

Install the exhaust camshaft bearing caps (B) and the front camshaft bearing cap (A).

Tightening torque

M6 bolts :

11.8 ~ 13.7 N.m (1.2 ~ 1.4 kgf.m, 8.7 ~ 10.1 lb-ft)

M8 bolts :

18.6 ~ 22.6 N.m (1.9 ~ 2.3 kgf.m, 13.7 ~ 16.6 lb-ft)

(19)

Turn the crankshaft two turns in the operating direction (clockwise), and then check that the TDC marks of the intake CVVT sprocket and the exhaust camshaft sprocket are in straight line on the cylinder head surface.

note

If the TDC marks are not aligned, reinstall the camshafts and the timing chain then recheck alignment of the TDC marks.

(20)

Install the service hole bolt (A) on the timing chain cover.

Tightening torque :

11.8 ~ 14.7 N.m (1.2 ~ 1.5 kgf.m, 8.7 ~ 10.8 lb-ft)

(21)

Install the cylinder head cover.

Яндекс.Метрика