Caution! A lifting mechanism must be used to remove the cylinder head. When installing the cylinder head, a new head gasket and a new camshaft bearing mounting bolt that controls the intake valves must be used.
Unscrewing the cylinder head mounting bolts
Removal
Screwing an additional bolt into the upper chain guide mounting pin
Using an inertia hammer to remove the top chain guide pin
Removal the intermediate sprocket of the drive chain
Removal the bearing from the front side of the camshaft
Removal the drive chain from the camshaft sprockets
Disconnecting the electrical connector from the fuel injector
Disconnecting the electrical connector from the coolant temperature sensor on a 3.0L engine
Removal the ground bus from the intake manifold of the 3.0L engine
Location of the wiring harness bracket on the intake manifold of the 3.0L engine
Disconnecting the vacuum hoses from the intake manifold
Location of the air pipe on the cylinder head
Air valve mounting bracket location
Unscrewing the fuel line from the pressure regulator on a 3.0L engine
Unscrewing the bracket for fastening the pipe for measuring the oil level
Unscrewing the bolt securing the dipstick pipe to the automatic transmission
Intake Manifold Support Bracket Mounting Bolts Location
A – bracket mounting bolts;
B – pipe fastening bolts
Location of the engine crankcase ventilation hose
Removal the cylinder head from the engine
1. Remove the cylinder head on a cold engine. The cylinder head is removed together with the intake and exhaust manifolds.
2. Remove the ground cable from the battery.
3. Open the hood and place it in a vertical position.
4. Drain the coolant and remove the radiator.
5. Disconnect the coolant supply hose from the rear left side of the cylinder head.
6. Set the piston of the first cylinder to TDC and check that all timing marks are aligned with the pointers.
7. Remove the upper drive chain cover.
8. Place alignment marks on the drive chain links and sprockets.
9. Screw an additional bolt into the upper chain guide mounting pin (see Fig. Screwing the additional bolt into the upper mounting pin of the chain guide).
10. Using a countersink hammer and an adapter, remove the additional bolt from the top of the chain guide mounting pin (see Fig. Using an inertia hammer to remove the top pin of the chain guide).
11. On 3.0L engines, remove the left-hand threaded bolt and drive chain idler sprocket (see Fig. Removing the intermediate sprocket of the drive chain).
12. From the front side of the camshaft that controls the intake valves, hold the bearing from turning, unscrew the bolt and remove the bearing (see Fig. Removing the bearing from the front side of the camshaft).
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13. Remove the drive chain from the camshaft sprockets and use soft wire to secure it from falling into the cover (see fig. Removing the drive chain from the camshaft sprockets).
14. Disconnect all electrical connectors from the cylinder head. Unscrew the bolt securing the wiring harness bracket to the manifold and move the wiring harness to the side (see Fig. Disconnecting the Electrical Connector from the Fuel Injector, Disconnecting the Electrical Connector from the Coolant Temperature Sensor on the 3.0L Engine, Removing the Ground Bus from the Intake Manifold on the 3.0L Engine, Locating the Wiring Harness Bracket on the Intake Manifold on the 3.0L Engine).
15. Disconnect the speed control system linkage.
16. Mark the location and disconnect all vacuum hoses from the intake manifold (see Fig. Disconnecting the vacuum hoses from the intake manifold).
17. Disconnect the exhaust pipe from the exhaust manifold.
18. Disconnect the air pipe from the cylinder head (see fig. Location of the air pipe on the cylinder head).
19. Unscrew the air valve mounting bracket and remove it together with the pipe from the engine (see Fig. Air valve mounting bracket location).
20. Relieve the pressure in the fuel system and unscrew the supply and return fuel lines (see fig. Unscrewing the fuel line from the pressure regulator on a 3.0 L engine).
21. Unscrew the bolt securing the bracket for the oil dipstick tube. Remove the dipstick and remove the tube from the cylinder block (see fig. Unscrewing the bracket for fastening the pipe for measuring the oil level dipstick).
22. Disconnect the accelerator cable from the throttle lever.
23. On automatic transmission models, disconnect the pressure control cable from the throttle linkage.
24. On models with automatic transmission, remove the transmission oil dipstick tube mounting bolts from the rear of the cylinder head (see Fig. Unscrewing the bolt securing the oil level dipstick pipe in an automatic transmission).
25. Unscrew and remove the two intake manifold support brackets (see Fig. Location of intake manifold support bracket mounting bolts).
26. From the back of the intake manifold, remove the clamp securing the vacuum hose and wiring harness.
27. Loosen the clamp and remove the crankcase ventilation hose from the breather housing under the intake manifold (see Fig. Location of the engine crankcase ventilation hose).
28. Loosen the clamp and remove the coolant supply hose from the elbow on the front of the engine.
29. Check that all hoses and electrical connectors are disconnected from the cylinder head.
30. Evenly and gradually loosen and unscrew the cylinder head mounting bolts in the reverse order shown in the figure Location of the engine crankcase ventilation hose.
31. Bolt the front engine lifting eye to the cylinder head.
32. Using a lifting device, remove the cylinder head (see Fig. Removing the cylinder head from the engine).
33. Remove the cylinder head gasket.
Preparing for installation
1. The mating surfaces of the engine head and cylinder block must be thoroughly cleaned of gasket residue and carbon deposits using a plastic or wooden scraper. It is also necessary to clean the upper parts of the pistons. When cleaning, eliminate the possibility of cleaning products getting into the oil channels of the cooling system. Thoroughly clean the inner surfaces of the cylinders.
2. Check the mating surfaces of the engine head and cylinder block for defects. Minor damage can be eliminated by mechanical treatment. Also, using a metal ruler and feeler gauge, check the flatness of the mating surfaces.
3. Clean the bolt holes in the block. Driving a bolt into an oil filled hole can cause the block to burst due to hydraulic pressure.
4. Measure the length of the cylinder head bolts (see fig. Preparation for installation). If the bolt length exceeds the allowable limits, replace the bolts as a set.
Installation
6-cylinder DOHC engine cylinder head bolt tightening sequence
1. Check that the crankshaft and camshaft timing marks are aligned with the pointers.
2. Install the cylinder head gasket onto the cylinder block guide pins.
3. Install the two rear cylinder head mounting bolts.
4. Using a lifting device, install the cylinder head onto the engine.
5. Remove the bolts and remove the front engine lifting eye from the cylinder head.
6. Lubricate the cylinder head bolts with engine oil and carefully insert them into the sockets. Tighten the head bolts by hand.
7. In the sequence shown in the 6-Cylinder DOHC Engine Cylinder Head Bolt Tightening Sequence figure, tighten the cylinder head bolts in several steps.
8. Further installation is carried out in the reverse order of removal. Fill the cooling system with coolant.