Cylinder head (Mitsubishi Space Star)

Removal

• Disconnect the cable from the negative battery terminal.
• Reduce the pressure in the fuel system.
• Drain the coolant from the cooling system.
• Remove the plug and drain the engine oil from the engine.
• Remove the thermostat housing.
• Unscrew the bolts and remove the accelerator cable mounting clamp (Fig. 3.30).

Fig. 3.30. Cylinder head: 1 - accelerator cable fastening clamp; 2 - crankcase ventilation hose; 3 - vacuum hose; 4 - Boost pressure sensor and bracket; 5 - brake booster vacuum hose; 6 - knock sensor connector; 7 - injector connector; 8 - connector for the temperature sensor of the air entering the engine; 9 - connector of the electromagnetic valve for cleaning the adsorber; 10 - EGR solenoid valve connector; 11 - ignition distributor connector; 12 - throttle position sensor connector; 13 Throttle control servo connector; 14 - wire connecting the engine cylinder block to ground; 15 - engine cooling system hoses; 16 - heater hose; 17 - High pressure fuel hose; 18 - fuel return hose

Fig. 3.31. Cylinder head: 1 - high voltage wires; 2 - cylinder head cover; 3 - Engine oil level indicator guide tube: 4 - Exhaust inlet pipe; 5 - intake manifold bracket; 6 - bolt, 13 Nm; 7 - cylinder head mounting bolt, 49 Nm + loosen + 20 Nm + 90° + 90°; 8 - cylinder head assembly; 9 - cylinder head gasket

• Loosen the clamp and disconnect the crankcase ventilation hose from the cylinder head cover pipe.
• Disconnect the vacuum hose.
• Remove the bolts and the boost pressure sensor and bracket,
• Loosen the clamp and disconnect the brake booster vacuum hose.
• Disconnect the connectors from the knock sensor, injectors, engine air temperature sensor, adsorber cleaning solenoid valve, exhaust gas recirculation solenoid valve, ignition distributor, throttle position sensor, and throttle control servo.
• Remove the bolt and disconnect the passage connecting the engine cylinder block to the ground.
• Loosen the clamps and disconnect the engine cooling and heater hoses.
• Remove the bolts, disconnect the high pressure fuel hose and remove the O-ring seal.
• Loosen the clamp and disconnect the fuel return hose.
• Remove the high voltage wires.
• Remove the bolts and remove the cylinder head cover.
• Remove the timing belt of the gas distribution mechanism drive.
• Remove the bolt and the engine oil level indicator guide tube together with the sealing ring.
• Loosen the nuts securing the exhaust pipe flange to the exhaust manifold.
• Remove the bolt and disconnect the exhaust inlet pipe from the exhaust manifold.
• Remove the bolts and intake manifold bracket.
• Unscrew the bolt and remove the engine cooling system pipe.
• Using a special tool, loosen and remove the cylinder head mounting bolts in 2 or 3 passes in the sequence shown in Figure 3.32.

Fig. 3.32. Sequence of unscrewing the cylinder head mounting bolts

• When removing the cylinder head bolts, be careful not to damage or deform the spark plug guide tubes, as they are not replaceable.
• Carefully remove the cylinder head.
• Remove the spark plug guide tube sealing rings.
• Remove the cylinder head gasket.
• Cover the engine cylinders with a clean, lint-free cloth.

Installation

• Installation is carried out in the reverse order of removal, taking into account the following.
• Degrease the mating surfaces of the block and cylinder head.
• When installing, check that all holes on the gasket and cylinder head are aligned.
• Install the gasket and cylinder head onto the cylinder block.
• Check the condition of the cylinder head bolts and especially their threads. Measure the length of each bolt (excluding the washer) from the underside of the bolt head to the end of the bolt. If the length of the bolts (A, Fig. 3.33) is less than 103.2 mm, they can be reused. If any bolt exceeds the specified length, replace all bolts in the set.

Fig. 3.33. Location of the cylinder head mounting bolt and washer: A = 103.2 mm

• Install washers on the cylinder head under the head mounting bolts, with the rounded side facing up, as shown in Figure 3.33.
• Before installation, lubricate the top surface of the washer and the bolt threads with engine oil.
• Tighten the cylinder head bolts in several stages in the sequence shown in Figure 3.34.

Fig.3.34 Sequence of tightening the cylinder head bolts

• step 1: Tighten to 49 Nm
• step 2: Loosen all bolts completely in the reverse order shown in Figure 3.34
• step 3: Tighten to 20 Nm
• step 4: Tighten the bolts by 90°. Mark the bolt heads and cylinder head with paint (Fig. 3.35)
• step 5: Tighten the bolts another 90° angle The marks on the bolts and the cylinder head should be in line (Fig. 3.35)

Fig. 3.35. Turning the cylinder head mounting bolts

Warnings.

• (1) Always tighten the bolt at an angle exactly equal to 90°. Otherwise, the cylinder head mounting bolt may become loose (the reliability of the gas connection will not be ensured).
• (2) If the bolt is turned to an angle greater than 90°, it is necessary to completely loosen it and repeat all bolt tightening operations.

• When installing the high pressure fuel hose, lubricate the O-ring with a small amount of clean engine oil (Fig. 3.36).

Fig. 3.36. Installing the high pressure fuel hose: 1 - place of lubrication with engine oil; 2 - fuel hose; 3 - O-ring gasket

Warning: Do not allow oil to enter the fuel line.

• While slightly turning the flange of the fuel hose to the right and left, carefully insert it into the fuel line so as not to damage the O-ring seal. After installation, check that the hose rotates smoothly in the fuel line.
• If the hose flange jams when turning, damage to the O-ring gasket may occur. Disconnect the flange (complete with hose) from the fuel line and check the gasket for any damage, then insert it back and check that it turns smoothly.
• Install the high pressure fuel hose mounting bolts and tighten them to 8.8 N·m.
• Install the thermostat housing.
• Connect and adjust the accelerator cable.
• Install the timing belt to drive the gas distribution mechanism.
• Fill the engine with the required amount of recommended motor oil.
• Fill the cooling system with coolant.
• Connect the cable to the negative terminal of the battery.
• Start the engine and check for leaks.