Cylinder Head Gasket: Service and Repair
Cylinder head assembly removal
CAUTION: When installing camshafts, chain tensioners, oil seals, or other sliding parts, lubricate contacting surfaces with new engine oil.
When tightening cylinder head bolts, camshaft sprocket bolts, crankshaft pulley bolt and camshaft bracket bolts, lubricate bolt threads and seat surfaces with new engine oil.
Attach tags to valve lifters so as not to mix them up.
Note: See Technical Service Bulletins for possible revisions to this procedure.
1. Drain coolant from drain plug on water pipe and radiator drain cock.
2. Remove vacuum hoses, fuel hoses, wires, harness and connectors.
CAUTION: Before disconnecting fuel hose, release fuel pressure.
3. Remove the following parts:
a. Generator and bracket.
b. Air duct.
c. Upper radiator hose.
d. Cooling fan assembly.
e. Front exhaust tube.
4. Remove the intake manifold collector supports, intake manifold and the exhaust manifold with warm-up three way catalyst.
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NOTE: When removing the intake and exhaust manifold, refer to the illustrations for fastener removal sequence.
5. Set No. 1 piston at TDC on its compression stroke.
6. Remove the distributor.
7. Set a suitable transmission jack under the aluminum oil pan and remove the front engine mounting.
8. Remove the rocker cover in numerical order.
9. Remove cam sprockets.
NOTE: Apply paint to upper timing chain and cam sprockets for alignment during installation.
The stoppers on the camshaft sprocket cover prevent upper timing chain from disengaging idler sprocket.
10. Remove camshaft brackets and camshafts.
NOTE: These parts must be reassembled in their original positions.
11. Loosen cylinder head bolts in numerical order, as shown in the illustration.
NOTE: Removing in incorrect order could result in a warped or cracked cylinder head. Loosen cylinder head bolts in 2 - 3 steps.
12. Remove the camshaft sprocket cover.
13. Remove the upper chain tensioner and the upper chain guides.
14. Remove the upper timing chain.
CAUTION: After removing timing chain, do not turn crankshaft and camshaft separately, or valves will strike piston heads.
15. Remove idler sprocket bolt. Apply paint to lower timing chain and idler sprocket for alignment during installation.
The stoppers on front cover prevent the lower timing chain from disengaging from the crankshaft sprocket.
16. Remove the cylinder head and cylinder head gasket.
Cylinder head installation
NOTE: When installing camshafts, chain tensioners, oil seals, or other sliding parts, lubricate contacting surfaces with new engine oil.
Apply new engine oil to bolt threads and seat surfaces when installing cylinder head, camshaft sprockets, crankshaft pulley, and camshaft brackets.
1. Install lower timing chain. Service and Repair
2. Install upper timing chain, chain tensioner and chain guide. Set upper timing chain on the idler sprocket and align the mating marks.
3. Install cam sprocket cover.
NOTE: Apply a continuous bead of liquid gasket to the camshaft sprocket cover.
Be careful not to damage the cylinder head gasket.
Be careful upper timing chain does not slip or jump off the idler sprocket.
4. Tighten cylinder head bolts using the following procedure:
a. Tighten all bolts to 29 Nm (22 ft lbs).
b. Tighten all bolts another 79 Nm (59 ft lbs).
c. Loosen all the bolts completely.
d. Tighten all bolts to 25 - 34 Nm (18 - 25 ft lbs).
e. Turn all bolts 86 to 91° clockwise. If an angle wrench is not available, mark all cylinder head bolts on the side facing the engine front. Then, turn each cylinder head bolt 86 - 91° clockwise.
5. Install camshafts and camshaft brackets using the following procedure:
a. Set camshafts and camshaft brackets properly.
b. Tighten all bolts as shown to 2 Nm (17 inch lbs).
c. Tighten all bolts to 9.0 - 11.8 Nm (79.9 - 104.2 inch lbs).
NOTE: Apply new engine oil to bolt threads and seat surfaces.
6. Install camshaft sprockets.
7. Install chain guide between both camshaft sprockets. Set upper timing chain on camshaft sprockets, aligning mating marks.
8. Install distributor.
NOTE: Make sure that No. 1 piston is set at TDC and that the distributor rotor is set at No. 1 cylinder spark position.
9. Install rocker cover gasket. Apply liquid gasket to rocker cover rubber gasket, cylinder head and camshaft sprocket cover.
10. Install rocker cover using the following procedure:
a. Tighten nuts (1), (5), (6) and (4) in that order to 4 Nm (35 inch lbs).
b. Tighten nuts (1) through (11) in numerical order to 8 - 11 Nm (69 - 95 inch lbs).
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11. Install the intake the exhaust manifold, refer to the illustrations for fastener tightening sequence.
12. Install all spark plugs with high tension cords.
13. Install vacuum hoses, fuel tubes, wires, harness and connectors.