Cylinder Head Assembly: Service and Repair
CYLINDER HEAD GASKETREMOVAL AND INSTALLATION
Pre-removal & Post-installation Operation:
Removal Steps 1-8:
Removal Steps 9-18:
Required Special Tools:
* MB990767: Front Hub and Flange Yoke Holder
* MB991654: Cylinder Head Bolt Wrench (12)
* MD998719: Pin
* MD998738: Adjusting Bolt
REMOVAL SERVICE POINTS
[[A]] CAMSHAFT SPROCKET REMOVAL
CAUTION: Never turn the crankshaft counterclockwise.
1. Turn the crankshaft clockwise, align the timing marks on the camshaft sprocket to set number 1 cylinder to TDC of its compression stroke.
2. Remove the timing belt under cover rubber plug and then set special tool MD998738.
3. Screw in special tool MD998738 until it contacts the timing belt tensioner arm.
4. Secure the camshaft sprocket and valve timing belt with wire to prevent slippage between the camshaft sprocket and valve timing belt.
5. Hold the camshaft sprocket with special tools MB990767 and MD998719.
CAUTION: Do not rotate the crankshaft after camshaft sprocket removal.
6. Remove the camshaft sprocket with the valve timing belt and place it on the timing belt lower cover.
[[B]] RADIATOR UPPER HOSE DISCONNECTION
Make mating marks on the radiator upper hose and the hose clamp. Disconnect the radiator upper hose.
[[C]] FUEL HIGH-PRESSURE HOSE DISCONNECTION
1. Remove the fuel high-pressure hose stopper.
2. Pull up the retainer and remove the fuel high-pressure hose in the direction shown.
NOTE: If the retainer is released, install it after removing the fuel high-pressure hose.
[[D]] CYLINDER HEAD BOLTS REMOVAL
Use special tool MB991654 to loosen the cylinder head bolts in two or three steps in the order shown in the illustration. If the cylinder head bolts cannot be pulled out due to the washer being trapped in the valve spring, raise the bolt slightly, then remove it while holding it with a magnet.
INSTALLATION SERVICE POINTS
]]A[[ CYLINDER HEAD GASKET INSTALLATION
CAUTION: Do not allow any foreign materials get into the coolant passages, oil passages and cylinder.
1. Degrease the cylinder head gasket mounting surface.
2. Assemble to the cylinder block so the cylinder head gasket identification mark of "381 " is at the top surface and on the exhaust side.
]]B[[ CYLINDER HEAD BOLTS INSTALLATION
1. Check that the nominal length of each cylinder head bolt meets the limit. If it exceeds the limit, replace the bolt with a new one.
Limit (A): 99.4 mm (3.91 inches)
2. Apply a small amount of engine oil to the thread of the bolts and to the washers.
3. Use special tool MB991654 to tighten the cylinder head bolts in the following procedures.
(1) Tighten the bolts to 78 ±2 Nm (58 ±1 ft-lb) in the order shown.
(2) Loosen the bolts fully in the reverse sequence of that shown.
(3) Tighten the bolts to 20 ±2 Nm (15 ±1 ft-lb) in the order shown.
(4) Reconfirm all bolts tightened firmly.
(5) Apply a paint mark to the heads of the cylinder head bolts and cylinder head, then tighten 90 degrees as shown.
CAUTION:
^ The bolt is not tightening sufficiently if the tightening angle is less than 90 degrees.
^ If the tightening angle exceeds the standard specification, remove the bolt and start over from step 1.
(6) Tighten 90 degrees as shown, then check to see that the paint mark on the head of the cylinder head bolt and the paint mark on the cylinder head are aligned.
]]C[[ FUEL HIGH-PRESSURE HOSE CONNECTION
CAUTION: After connecting the fuel high-pressure hose, slightly pull it to ensure that it is installed securely. Also confirm that there is a play approximately 3 mm (0.12 inch). Then install the stopper securely.
Apply a small amount of engine oil to the fuel line pipe and then in tall the fuel high-pressure hose.
]]D[[ RADIATOR UPPER HOSE CONNECTION
1. Insert radiator upper hose until it contacts the projection on the water outlet fitting.
2. Align the mating marks on the radiator upper hose and hose clamp, and then secure the radiator upper hose.
]]E[[ CAMSHAFT SPROCKET INSTALLATION
1. Hold the camshaft sprocket with special tools MB990767 and MD998719 in the same manner as removal.
2. Tighten the camshaft sprocket mounting bolt to the specified torque.
Tightening torque: 89 ±9 Nm (65 ±7 ft-lb)
]]F[[ BRAKE BOOSTER VACUUM HOSE CONNECTION
Insert the vacuum hose with its paint mark facing upward.