REMOVAL & INSTALLATION
REVIEW ENTIRE PROCEDURE BEFORE STARTING THIS REPAIR. MAKE SURE TO LOCATE THE CORRECT YEAR, ENGINE AND MODEL SERVICE PROCEDURE FOR YOUR VEHICLE.3.0L Engines
EXCEPT PREMIER AND MONACO
See Figures 1 through 18
- Relieve the fuel system pressure. For more details, refer to Fuel System .
- Drain the cooling system. For more details, refer to General Information & Maintenance .
- Disconnect the negative battery cable.
- Raise the vehicle so that access to the top and bottom of the engine compartment can be gained, then remove the right inner splash shield.
- Remove the accessory drive belts. Refer to General Information & Maintenance for this procedure.
- Label, then remove the spark plug cables from the distributor.
- Remove the distributor. For more details, refer to Engine Electrical .
- If applicable, remove the air conditioning compressor-to-mounting bracket bolts and lay the compressor aside without disconnecting the A/C lines.
- Remove the bolts attaching the A/C mounting compressor bracket and adjustable drive belt tensioner from the engine block and engine mounting bracket. Remove both assemblies.
- Remove the steering pump/alternator belt tensioner mounting bolt and remove the automatic belt tensioner.
- If applicable, remove the two power steering pump-to-engine mounting bracket bolts and one rear support locknut.
- Support the power steering pump to the side without disconnecting the power steering lines.
- Remove the crankshaft drive pulleys and torsional damper. A special torsional damper puller is not required for this procedure.
- Lower the vehicle and place a jack under the engine. Make sure to use a piece of wood between the jack and the engine.
- Separate the engine mount insulator from the engine mount bracket. Using the floor jack, raise the engine slightly.
When removing the engine mount bracket, front engine bracket and the 3 timing belt covers, make sure to label the locations of the retaining bolts. These bolts are of different lengths and need to be reinstalled in the same positions as when removed.
- Remove the engine mount bracket.
- Remove the three timing belt covers from the engine by removing the retaining bolts.
- Mark the timing belt with an arrow in the direction of travel for reinstallation.
- Loosen the timing belt tensioner bolt and remove the timing belt from the camshaft, water pump and crankshaft sprockets.
- Remove the crankshaft sprocket flange shield.
- Hold the camshaft sprockets with the special tool (MB990775), then loosen and remove the retaining bolt and washer.
- Remove the camshaft sprocket from the camshaft.
- Remove the air cleaner assembly.
- Label, then disconnect the spark plug cables from the cylinder heads.
- Remove any vacuum connections to the rocker arm covers or intake manifolds.
- Remove the rocker arm cover attaching bolts and remove the covers from the cylinder heads.
- Install the auto lash adjuster retainers (part number: MD998443) to the rocker arm shaft assemblies.
- Remove the distributor extension.
- When removing the camshaft bearing caps do not remove the bolts from the bearing caps. Remove the rocker arm, rocker shafts and bearing cap as an assembly.
- Remove the front oil seals and the rear camshaft seals. New seals will be needed upon installation.
- Remove the intake manifold and fuel injector assemblies.
- Remove the exhaust manifolds by referring to the procedure described later in this section.
- Remove the cylinder head bolts in the sequence shown in the illustration, then remove the cylinder heads from the engine block.
- Clean the head and block, install the head gasket over the locating dowels on the engine block.
- Install the head onto the engine block with the locating dowels in dowel holes in the head.
- Install the 0.40 in. (10mm) Allen hex head bolts with the washers into the cylinder head holes. Although not necessary, it is a good idea to use new cylinder head bolts. If the bolts show any signs of stress or damage, replace the old bolts with new ones.
- Tighten the bolts in the order shown in the illustration. When tightening the cylinder head bolts, tighten them gradually, working in two or three steps to the specified value of 70 ft. lbs. (95 Nm).
- Install the exhaust manifolds. For more details, refer to the exhaust manifold procedures described earlier in this section.
- Install the intake manifold. For more details, refer to the intake manifold procedures described earlier in this section.
- Lubricate the camshaft journals and cams with engine oil and install the camshaft onto the cylinder head.
- Before reassembly, coat the contact faces liberally with clean motor oil.
- Apply sealant at the bearing cap ends as shown in the illustration.
- Carefully fit the rocker shaft assembly onto the head. Remember that the camshaft must be held in place during this exchange.
- Install the retaining bolts finger-tight, making sure each rocker is correctly aligned with the camshaft and valve stem. Once the rockers are securely in place, the special retaining clips may be removed.
- Starting at the No. 3 bearing cap and working in the correct order (No. 3, No. 2, No. 1, then No. 4) in two passes, tighten the bearing cap bolts to 15 ft. lbs. (20 Nm).
- Install the distributor drive adapter assembly with a new O-ring onto the cylinder head.
- Apply a light coat of engine oil to the new camshaft oil seal lip.
- Install the new oil seal using the camshaft oil seal installer tool MD998713.
- Install a new end seal (plug) with the tool MB998306 to the other end of the cylinder head.
- Place the camshaft sprocket on the end of each camshaft.
- Install the bolt and washer onto the camshaft. Using tool MB990775, hold the camshaft sprocket steady while tightening the bolt to 70 ft. lbs. (95 Nm).
If the timing belt tensioner was removed, install with this procedure:
- Install the timing belt tensioner and tensioner spring to the engine block.
- Hook the spring upper end to the water pump pin and lower end to the tensioner bracket with the hook "out.''
- Turn the timing belt tensioner counterclockwise for the full travel distance in the adjustment slot, then tighten the bolt to temporarily hold the tensioner in this position.
- Make sure that the crankshaft and camshaft sprockets' timing marks are aligned with those on the engine.
- Install the timing belt to the crankshaft sprocket first and, while keeping the belt tight on the tension side, install the belt onto the front (radiator side) camshaft sprocket.
- Install the belt under the water pump pulley and up and over the rear camshaft sprocket, then finally onto the inside of the tensioner pulley.
- Apply rotating force to the front camshaft sprocket in the opposite direction to tension the tension side and check that all of the timing marks are lined up. Make certain that all of the timing belt teeth are correctly seated in the sprockets.
- Install the crankshaft sprocket flange.
- Loosen the tensioner bolt slightly and allow the spring to tension the timing belt.
- Turn the crankshaft two full turns in a clockwise direction. Turn smoothly and in the clockwise direction ONLY.
- Again line up the timing marks on the sprockets and tighten the timing belt tensioner locking bolt to 18.5 ft. lbs. (25 Nm).
- Install the engine bracket to the engine and tighten the bolts to 35 ft. lbs. (47 Nm). Install the insulator to the engine bracket and tighten the through-bolt and nut to 100 ft. lbs. (136 Nm). Lower the engine until the insulator and vehicle frame insulator mounting pads line up and are barley touching. Install the two insulator-to-vehicle frame bolts and tighten to 50 ft. lbs. (68 Nm). Lower the engine until it is supported fully by the engine bracket and insulator. Remove the jack from under the engine.
- Install the torsional damper to the crankshaft by tightening the crankshaft bolt until the damper is seated flush against the crankshaft sprocket flange. Tighten the crankshaft bolt to 81 ft. lbs. (110 Nm). While installing the damper or tightening the crankshaft bolt, it will be necessary for an assistant to keep the engine from turning by holding a flywheel or flexplate bolt or to use a special damper holding tool (much like the camshaft sprocket tool).
- Install the two crankshaft pulleys. Tighten the pulleys bolts until tight.
- Raise the vehicle and install the right inner splash shield.
- Lower the vehicle.
- Install the power steering pump, refer to Suspension & Steering for this procedure.
- Install the steering pump/alternator belt tensioner and tighten the mounting bolt until tight.
- Install the A/C compressor and tensioner assembly. Refer to Chassis Electrical for this procedure.
- Install the distributor into the engine. Refer to Engine Electrical for this procedure.
- Install the accessory drive belts. Refer to General Information & Maintenance for this procedure.
- Install the air cleaner assembly and install the spark plug cables to the distributor and spark plugs.
- Connect the negative (-) battery cable. Refill the cooling system.
- Start the engine and allow it to warm up to the normal operating temperature. Check the coolant fluid level and fill if needed. Check the engine for fuel, oil, vacuum or coolant leaks.
When starting the engine, it may take longer for the engine to start because the fuel system needs to pressurize itself. Crank the engine over in short 4-6 second long periods with a rest of 10-20 seconds in between.PREMIER AND MONACO
See Figures 19 through 30
When removing the cylinder head, the exhaust manifolds must be first be removed. Install the exhaust manifolds after the cylinder head and gasket have been installed. This is to prevent damage to the cylinder head gasket tabs.
- Relieve the fuel system pressure. For more details refer to Fuel System .
- Disconnect the negative battery cable and drain the cooling system.
- Remove the accessory drive belt and remove the air conditioning compressor from the cylinder head cover.
- Remove the intake and exhaust manifolds.
- Remove the spark plug wires.
- Remove the rocker arm cover.
- Remove the alternator mounting bracket and remove the top timing case bolts that thread into the cylinder head.
The timing sprocket and chain must be supported in place and not allowed to drop into the timing case. If the chain and sprocket slip into the engine the timing case will have to be removed.
Turn the crankshaft until the camshaft sprocket dowel is straight up. A special tool is available called a timing chain support bracket (No. 7317). This support bracket and dummy bearing attaches to the timing case cover. Attach the special tool as follows:
- Secure the tool to the timing case cover with two short rocker arm cover bolts.
- Position the adjusting lever behind the camshaft sprocket. Thread the adjusting lever bolt through the front of the tool, sprocket and into the lever. Push the lever up as far as possible. Tighten the adjusting lever bolt.
- Remove the threaded plug on the front of the timing case cover to gain access to the camshaft sprocket bolt.
To remove the camshaft sprockets from the camshafts, perform the following:
- Loosen the camshaft thrust plate bolt. Pull the thrust plate up and away from the camshaft. Tighten the camshaft thrust plate bolt.
- Remove the timing case cover-to-cylinder head mounting bolts.
- Place a socket or wrench on the crankshaft pulley nut to prevent the engine from turning over.
- Loosen the camshaft sprocket bolt and pull the camshaft back until the bolt is free from the camshaft.
- On the left cylinder head, remove the distributor cap, rotor and dust shield assembly.
- Remove the cylinder head bolts. Remove the rocker shaft assembly.
Note the position that the rocker arm caps are in; they are pinned into the head and will only go on in one direction.
- Position one cylinder head bolt into a middle bolt hole and tighten it two full turns.
- Use an old pushrod or a long thin drift punch as a tool and insert it into the front and rear cylinder head bolt holes on the exhaust manifold side of the head. Tap the dowel down below the head gasket. The reason for this is that the cylinder head is not to be removed by pulling straight upward which would pull the cylinder liners loose from the block. It is to be bumped sideways to break the seal.
Do not pull straight up on the cylinder head to remove it. This will cause the cylinder liners to come out of the block.
- Position a block of wood on the intake manifold side of the head and strike it with a hammer, do the same on the exhaust manifold side of the head. Repeat this until the cylinder head is loose.
- Remove the last head bolt from the head. Remove the cylinder head.
When the cylinder head has been removed, retain the cylinder liners in the block with a liner hold-down clamp (7315). This tool is designed to prevent the cylinder liners from being knocked out of position. If this happens, the sealing rings will dislodge or rip. Do not rotate the engine with the liner clamps in place.
- Remove the cylinder head gasket from the engine block.
- Use the special tool (7314) to remove the cylinder head locating dowels.
- Stuff the cylinder bores with clean, lint-free shop towels.
- Install the cylinder liner clamps (7315) to hold the liners in place.
- Use a gasket removal compound to soften the old gasket material.
- Make sure that the gasket and/or foreign material does not enter the oil feed hole or the oil return hole.
- Rinse and wipe clean the cylinder block and cylinder head mating surfaces.
- Check the liner protrusion. The liner protrusion should be between 0.002-0.005 in. (0.05-0.12mm). Refer to the cylinder and liners procedures appearing later in this section.
- When installing, cut the gasket flush with the cylinder head gasket face at the back of the timing case cover and remove the pieces. Clean the back of the timing cover. Cut sections of new gasket to replace the pieces removed and attach them with adhesive.
- Install a small punch (0.12 in./3mm diameter) into the hole in the block below the locating dowel bolt holes. This will act as a stop for the dowel. Push the dowel into the block until it contacts the punch.
- Remove the shop towels from the cylinder bores.
- Install a new cylinder head gasket over the alignment dowels on the head. Place a small bead of RTV sealant or the equivalent, at the point where the head gasket meets the timing case cover.
- Place the cylinder head on the block, taking care not to dislodge the timing case cover gasket.
- Install the top timing case cover-to-cylinder head bolts finger-tight.
- Position the camshafts into the sprockets and align the dowel to the slot in the camshaft. Install the sprocket bolt and tighten it lightly.
- Remove the support bracket assembly (tool 7317).
- Loosen the camshaft thrust plate bolt and slide the thrust plate into position. Tighten the thrust plate bolt to 9 ft. lbs. (12 Nm).
- Remove the punches in the engine block (0.12 in./3mm diameter).
The cylinder head bolts must be examined BEFORE reuse. If the threads are necked down (stretched) the bolts should be replaced.
Necking can be checked by holding a scale or straightedge against the threads. If all of the threads do not contact the scale the bolt should be replaced with a new one.
- Install the rocker shaft assembly and head bolts (either new ones or non-stretched used ones).
Using the proper sequence, tighten the cylinder head bolts in the following order:
- Starting with bolt No. 1, pre-tighten all bolts to 44 ft. lbs. (60 Nm).
- The following is performed on all bolts, one at a time, in their proper sequence (see illustration). Starting with bolt No. 1, loosen the bolt completely, then retighten to 30 ft. lbs. (41 Nm).
- Place an angle adapter (graduated disc tool) on the torque wrench between the socket and wrench.
- Turn the graduated disc clockwise until the locking stem rests against a solid object, which will prevent the disc from turning.
- Angle tighten bolt No. 1 an additional 160-200°.
- Repeat the procedure for each bolt, in the proper sequence.
- Once all bolts have been angle tightened, check each bolt for at least 52 ft. lbs. (70 Nm) of torque.
- Tighten the timing case cover bolts to 9 ft. lbs. (12 Nm).
- Tighten the camshaft sprocket bolt to 59 ft. lbs. (80 Nm) while holding the crankshaft bolt with a wrench or socket.
- Cut off any timing case cover gasket flush with the cylinder head.
- Install the rocker arm covers.
- Install the intake and exhaust manifolds.
- Install the distributor rotor, cap and dust shield or the DIS ignition coils.
- Coat the threads of the timing case cover plug with Loctite® PST pipe sealant No. 592 or the equivalent.
- Install the plug in the front of the timing case cover.
- Install the spark plug wires and the air conditioning compressor, if removed.
- Connect the alternator bracket.
- Reconnect all hoses and fill the cooling system.
- Install the accessory drive belt and adjust the tension.
- Connect the negative battery terminal.
- Start the engine, allow it to warm up to normal operating temperature and bleed the cooling system.
- Check for fuel, oil, coolant and vacuum leaks.
3.3L and 3.8L Engines
See Figures 31, 32, 33 and 34
The aluminum cylinder heads are held in place by 9 bolts. The spark plugs are located in the peak of the wedge between the valves.
- Relieve the fuel system pressure. For more details refer to Fuel System .
- Disconnect the negative battery cable. Drain the cooling system.
- Remove the intake manifold and the throttle body. Refer to the procedures found earlier in this section.
- Disconnect the coil wires, coolant temperature sending unit wire, heater hoses and bypass hose.
- Remove the closed ventilation system hoses, evaporation control system hoses and valve cover.
- Remove the exhaust manifolds. Refer to the exhaust manifold procedures described earlier in this section.
- Remove the rocker arm and shaft assemblies, as explained earlier in this section. Remove the pushrods and identify them to ensure installation to their original positions.
- Remove the head bolts and remove the cylinder head from the block.
- Before cleaning, check the cylinder heads for leaks, damage and cracks.
- Clean the cylinder head and oil passages, then check the head for flatness-refer to the procedure later in this section.
- Clean the gasket mounting surfaces and install a new head gasket to the block.
- Install the head to the block. The bolts used with the 3.3L and 3.8L engines are made to stretch at certain torque values, this is not a malfunction of the bolt. Before installing the head bolts, inspect them for stretching. Hold a straight-edge up to the threads (see the illustration). If the threads are not all on line, the bolt is stretched and should be replaced. It is extremely important to perform this check, since if the bolts are stretched and then reused, they could break off in the engine block, which would definitely put a damper on the whole experience and could require machining facilities.
- Tighten bolts 1-8 in sequence to 45 ft. lbs. (61 Nm). Repeat the sequence but tighten the bolts to 65 ft. lbs. (88 Nm). Once again tighten the bolts to 65 ft. lbs. (88 Nm). With the bolts at 65 ft. lbs., turn each bolt with a regular socket wrench (do not use a torque wrench with a flexible beam for this last step) an additional 1 / 4 turn (90°).
- The bolt torque after the 1 / 4 turn should be over 90 ft. lbs. (122 Nm). If it is not, replace the bolts with new ones.
- Tighten the lone head bolt in the rear of the head (bolt No. 9) to 25 ft. lbs. (33 Nm) after the other 8 bolts have been properly tightened.
- The balance of the installation is the reverse of the removal.
- Connect the negative battery cable.
- Start the engine and check for coolant, fuel, vacuum and oil leaks.
Refill the cooling system.
When starting the engine, it may take longer fo the engine to start because the fuel system needs to pressurize itself. Crank the engine over in short 4-6 second long periods with a rest of 10-20 seconds inbetween.