Removal & Installation
- Before servicing the vehicle, refer to the Precautions section.
- Remove the engine from the vehicle and mount it on a suitable workstand.
Remove or disconnect the following:
Accessory drive belt and tensioner
The cylinder head bolts are a torque-to-yield design and cannot be reused.
Use new gaskets and install the cylinder heads. Tighten the cylinder head bolts in sequence as follows:
- Step 1: 28-31 ft. lbs. (37-43 Nm).
- Step 2: Tighten the bolts 85-95 degrees.
- Step 3: Loosen all bolts 1 full turn.
- Step 4: Tighten all bolts to 28-31 ft. lbs. (37-43 Nm).
- Step 5: Tighten the bolts 85-95 degrees.
- Step 6: Tighten the bolts 85-95 degrees.
Install or connect the following:
- Drain the cooling system, then disconnect the negative battery cable.
- Properly relieve the fuel system pressure.
- Remove the air cleaner assembly including air intake duct and heat tube.
- Loosen the accessory drive belt idler, then remove the drive belt.
If the left cylinder head is being removed, perform the following:
- Remove the power steering pump. Leave the hoses connected and place the pump/bracket assembly aside in a position to prevent the fluid from leaking out.
- If equipped with air conditioning, remove mounting bracket attaching bolts. Leaving the hoses connected, position the compressor aside.
- Remove the alternator and bracket.
If the right cylinder head is being removed, perform the following:
- Disconnect the thermactor air control valve or bypass valve hose assembly at the air pump.
- If equipped, disconnect the thermactor tube support bracket from the rear of cylinder head.
- Remove the accessory drive idler pulley.
- Remove the PCV valve.
- Remove the upper intake manifold. For details, please refer to the procedure located earlier in this section.
- Remove the valve/rocker arm cover retaining bolts, then remove the covers.
- Remove the injector fuel rail assembly.
- Remove the lower intake manifold and the exhaust manifold(s). For details, please refer to the procedure located earlier in this section.
- Loosen the rocker arm fulcrum attaching bolts enough to allow rocker arm to be lifted off the pushrod and rotate to one side. Remove the pushrods. Identify and label the position of each pushrod. Pushrods should be installed in their original position during assembly.
You must use new cylinder head retaining bolts and gaskets when replacing or reinstalling the cylinder head!
- Remove the cylinder head attaching bolts and discard. Do NOT reuse the old bolts.
- Remove the cylinder head(s).
- Remove and discard old cylinder head gasket(s).
- Lightly oil all bolt threads before installation.
- Clean cylinder head, intake manifold, valve rocker arm cover, and cylinder head gasket contact surfaces. If cylinder head was removed for a cylinder head gasket replacement, check flatness of cylinder head and block gasket surfaces.
- Position the new head gasket(s) onto cylinder block using dowels for alignment. Position cylinder head(s) onto block.
- Apply a thin coating of pipe sealant with Teflon® to the threads of the short cylinder head bolts, nearest to the exhaust manifold. Do not apply sealant to the long bolts. Install the cylinder head bolts.
Always use new cylinder head bolts to ensure a leak-tight assembly. Torque retention with used bolts can vary, which may result in coolant or compression leakage at the cylinder head mating surface area.
For vehicles through 1994, tighten the cylinder head attaching bolts, in sequence, to the following specifications:
Step 1:37 ft. lbs. (50 Nm)
For vehicles through 1992, retighten the cylinder head bolts, in sequence, one at a time in the following manner:
- Long cylinder head bolts: Loosen the bolts and back them out 2-3 turns. Retighten to 11-18 ft. lbs. (15-25 Nm). Then tighten the bolt an additional 85-105° and go to the next bolt in sequence.
- Short cylinder head bolts: Loosen the bolts and back them out 2-3 turns. Retighten to 11-18 ft. lbs. (15-25 Nm). Then tighten the bolt an additional 65-85°.
For 1993-94 vehicles, retighten the cylinder head bolts, in sequence, one at a time in the following manner:
- Long cylinder head bolts: Loosen the bolts and back them out 2-3 turns. Retighten to 11-18 ft. lbs. (15-25 Nm). Then tighten the bolt an additional 85-95° and go to the next bolt in sequence.
- Short cylinder head bolts: Loosen the bolt and back them out 2-3 turns. Retighten to 7-15 ft. lbs. (10-20 Nm). Then tighten the bolt an additional 85-95°.
When cylinder head attaching bolts have been tightened using the above procedures, it is not necessary to retighten bolts after extended engine operation. However, bolts can be checked for tightness if desired.
- Dip each pushrod end in oil conditioner or heavy engine oil, then install the pushrods in their original position.
- For each valve, rotate crankshaft until the tappet rests on the heel (base circle) of the camshaft lobe. Torque the fulcrum attaching bolts to 44 inch lbs. (5 Nm) maximum.
- Lubricate all rocker arm assemblies with oil conditioner or heavy engine oil.
- Tighten the fulcrum bolts a second time to 19-25 ft. lbs. (26-34 Nm). For final tightening, camshaft may be in any position.
If original valve train components are being installed, a valve clearance check is not required. If a component has been replaced, perform a valve clearance check.
- Install the exhaust manifold(s) and the lower intake manifold. For details, please see these procedures located earlier in this section.
- Install the injector fuel rail assembly. Tighten the retaining bolts to 71-97 inch lbs. (8-11 Nm).
- Position the rocker arm/valve cover(s) and new gasket on cylinder head and install attaching bolts. Note location of spark plug wire routing clip stud bolts. Tighten attaching bolts to 80-106 inch lbs. (9-12 Nm).
- Install the upper intake manifold, then connect the ignition wires to the spark plugs.
- If the left cylinder head is being installed, perform the following: install oil fill cap, compressor mounting and support brackets, power steering pump mounting and support brackets and the alternator/support bracket.
- If the right cylinder head is being installed, perform the following: install the PCV valve, alternator bracket, thermactor pump and pump pulley, accessory drive idler, thermactor air control valve or air bypass valve hose.
- Install the accessory drive belt. Attach the thermactor tube(s) support bracket to the rear of the cylinder head. Tighten the attaching bolts to 30-40 ft. lbs. (40-55 Nm).
- Install the air cleaner assembly, including the air intake duct and heat tube.
- Connect the negative battery cable and fill the cooling system.
- Start the engine and check for leaks.
- To remove the head on a 4.6L engine that is a front-wheel drive, it is first necessary to remove the engine from the vehicle. Since an explanation on how to remove the engine has already been given in this section and a detailed account of how to disassemble the head follows this, an abbreviated account on removal of the head is given here.
- Remove the engine from the vehicle.
- Remove the valve covers.
- Remove the front engine covers.
- Remove the intake manifold.
- Remove the crankshaft position sensor pulse wheel.
- Remove the rocker arms.
- remove the exhaust manifolds.
- Drain the engine coolant from the cylinder block.
- Rotate the engine to No. 1 top dead center (TDC).
- Install the camshaft position tool in the rear D-slots of the camshafts.
- Remove the bolts retaining The RH and LH primary timing chain tensioners to the cylinder heads and remove the timing chain tensioners.
- Remove the LH and RH primary timing chains, timing chain tensioner arms, and timing chain guides. Do not loosen the camshaft-timing sprocket retaining bolts.
- Remove the outlet heater water hose retaining bolts from the rear of the RH cylinder head.
- Using the reverse of the torque sequence, loosen and remove the 10 cylinder head bolts.
- The cylinder head bolts are torque to yield and must be replaced. Do not re-use the old head bolts. Discard them.
- Remove the heads. Remove the head gaskets.
The cylinder heads must not be set on the head face if the valves are open. Damage may occur to the valves.