UPPER
- Clean and inspect the gasket sealing surfaces. Gaskets can be reused if free of cuts or tears. NOTE: Make sure the fuel injectors and wiring harnesses are positioned to not interfere with upper manifold installation.
- Position the upper intake manifold onto the lower intake manifold.
- Install the manifold attaching bolts and tighten in the sequence shown in illustration to 12 N.m (105 in. lbs.).
- Connect the Positive Crankcase Ventilation (PCV) hose (1).
- Connect the electrical connectors to the Manifold Absolute Pressure (MAP) sensor (2) and the Electronic Throttle Control (ETC) (3).
- Connect the brake booster hose (1) and the vapor purge hose (2) to the upper intake manifold.
- Install the upper EGR tube (3). Refer to «Emissions Control/Exhaust Gas Recirculation/TUBE, Exhaust Gas Recirculation (EGR) - Installation»(ref-353616-S17473794012010011200000) .
- Install the two intake manifold support brackets (1). Tighten the fasteners to 12 N.m (105 in. lbs.).
- Install the air cleaner housing assembly and connect the throttle body air inlet hose (2). See «Engine/Air Intake System/BODY, Air Cleaner - Installation»(ref-353618-S14117192912010011200000) .
- Connect the negative battery cable and tighten nut to 5 N.m (45 in. lbs.).
Scheme 753
- Clean and inspect sealing surfaces of cylinder head and manifold. Gaskets can be reused provided they are free of cuts or tears.
- Position manifold on cylinder head surfaces. NOTE: For ease of installing upper intake manifold, install a bolt 2 - 3 turns to the rearmost attaching hole of intake. This will properly position lower manifold.
- Install manifold attaching bolts and tighten in sequence shown in illustration, to 12 N.m (105 in. lbs.). Remove bolt used for aligning manifold.
- Install fuel rail with injectors.
- Connect the fuel injector electrical connectors. NOTE: Make sure fuel injectors are located in the correct location and position, as upper intake manifold interference could occur.
- Install screw attaching fuel rail support bracket to the throttle body support bracket.
- Connect fuel supply hose to fuel rail.
- Install upper intake manifold. See «Engine/Manifolds/MANIFOLD, Intake - Installation»(ref-353618-S18975037872010011200000) .
Scheme 754
The timing drive system has been designed to provide quiet performance and reliability to support a NON free-wheeling engine. The system consists of a primary (5) drive chain and a secondary chain drive.
The primary timing chain (5) is a double-flexure, inverted tooth type chain. The primary chain drives both of the intake camshafts directly from a sprocket mounted on the crankshaft. In addition, the water pump is driven by the "back side" of the primary chain, necessitating the double-flexure type chain.
The chain is controlled by three fixed chain guides (2), (7), (11) and a pivoting tensioner arm (8). These guides utilize low-friction and long wearing nylon plastic wear faces. To tension the primary chain, a fully automatic spring-loaded, engine oil-fed, hydraulic tensioner (9) is used. The tensioner (9) is mounted in the right cylinder head with the plunger contacting the pivoting tensioner arm (8). A mechanical ratchet mechanism inside the tensioner prevents excessive chain slack upon engine start-up as the chain wears. The tensioner is designed with an internal oil reservoir to assure noise-free performance, even during engine start-up before oil pressure reaches the tensioner.
For lubrication the primary chain utilizes oil leakage from the front of the oil pump. This oil spills on the crankshaft sprocket, which is then carried by the chain throughout the primary drive.
Scheme 755
The secondary timing chain (11) drive system uses either two conventional roller-type chains (early production) or two silent type chains (late production), one at each cylinder bank. The purpose of the secondary chain (11) is to provide a mechanical driven connection between the intake and exhaust camshafts. The intake camshafts drive the exhaust camshafts. The sprockets for both intake and exhaust camshafts are a press-fit and are only serviced as an assembly with the camshafts.
To tension the secondary chain, spring-loaded, hydraulic tensioners (7) are used at each bank and attach to each cylinder head between the intake and exhaust camshafts. The tensioner (7) incorporates upper and lower chain guide faces. The lower guide face is attached directly to the tensioner's hydraulic plunger. Also, the tensioner uses an internal oil reservoir design to prevent engine start-up noise. The secondary chains are lubricated via an oil passage through the upper guide face on each tensioner.
Scheme 756
| 1 - 12 PINS | 3 - 12 PINS |
|---|---|
| 2 - CAMSHAFT TIMING MARKS |
Note. Note: The engine timing verification procedure is the same for both conventional roller-type (early production) or silent type (late production) secondary timing chains.
Correct timing is critical for the NON free-wheeling designed, 2.7L engine. Engine timing can be verified by using the following procedures
- Remove cylinder head covers. See «Engine/Cylinder Head/COVER(S), Cylinder Head - Removal»(ref-353618-S35378812432010011200000) .
- Rotate engine until number one cylinder is at TDC on the EXHAUST stroke.
- View the intake camshaft sprocket timing mark. The mark should be 90° from the cylinder head cover sealing surface on both right and left cylinder banks.
- Count the chain pins between the timing marks (2) on the intake camshaft and the exhaust camshaft. Engine is timed correctly when there are 12 chain pins between the timing marks (2) on the intake camshaft and exhaust camshaft.
- If marks are not correctly aligned, proceed to «Engine/Valve Timing/CHAIN and SPROCKETS, Timing - Removal»(ref-353618-S07109882762010011200000) .
Scheme 757
| 1 - CAMSHAFT TIMING MARKS |
|---|
| 2 - CRANKSHAFT TIMING MARKS |
Scheme 758
Scheme 759
- Disconnect negative battery cable.
- Drain cooling system.
- Remove upper intake manifold. See «Engine/Manifolds/MANIFOLD, Intake - Removal»(ref-353618-S26296796972010011200000) .
- Remove cylinder head covers, crankshaft vibration damper, and timing chain cover. See «Engine/Cylinder Head/COVER(S), Cylinder Head - Removal»(ref-353618-S35378812432010011200000) , «Engine/Engine Block/DAMPER, Vibration - Removal»(ref-353618-S27047139172010011200000) or «Engine/Valve Timing/COVER(S), Engine Timing - Removal»(ref-353618-S33729398542010011200000) . CAUTION: When aligning timing marks, always rotate engine by turning the crankshaft. Failure to do so will result in valve and/or piston damage.
- Align crankshaft sprocket timing mark to mark on oil pump housing (2). The mark on oil pump housing is 60° ATDC of #1 cylinder. CAUTION: When the timing chain is removed and the cylinder heads are still installed, DO NOT rotate the camshafts or crankshaft without first locating the proper crankshaft position. Failure to do so will result in valve and/or piston damage. 1 - TENSIONER 2 - RETAINER CAP 3 - BOLT
- Remove power steering pump and bracket as an assembly. Do not disconnect power steering lines from pump. Reposition pump and support with suitable retaining strap.
- Remove primary timing chain tensioner retainer cap (2) and tensioner (1) from right cylinder head.
- Disconnect and remove camshaft position sensor from left cylinder head.
- Remove timing chain guide access plugs from cylinder heads. 1 - CAMSHAFT DAMPER (IF EQUIPPED) 7 - CHAIN GUIDE 2 - CHAIN GUIDE 8 - CHAIN TENSIONER ARM 3 - ACCESS PLUG 9 - CHAIN TENSIONER 4 - CAMSHAFT POSITION SENSOR 10 - CAMSHAFT SPROCKETS 5 - PRIMARY TIMING CHAIN 11 - CHAIN GUIDE 6 - CRANKSHAFT SPROCKET NOTE: When camshaft sprocket bolts are removed, the camshafts will rotate in a clockwise direction.
- Starting with the right camshaft sprocket, remove the sprocket attaching bolts. Remove camshaft damper (if equipped) and sprocket.
- Remove left side camshaft sprocket attaching bolts and remove sprocket.
- Remove lower chain guide (7) and tensioner arm (8).
- Remove the primary timing chain.
- For removal of crankshaft sprocket, see «Engine/Engine Block/CRANKSHAFT - Removal»(ref-353618-S31692861992010011200000) .
Scheme 760
| 1 - SPECIAL TOOL 8539 |
|---|
| 2 - SPECIAL TOOL 5048-6 |
| 3 - SPECIAL TOOL 5048-1 |
- Remove primary timing chain. See «Engine/Valve Timing/CHAIN and SPROCKETS, Timing - Removal»(ref-353618-S07109882762010011200000) . CAUTION: Use care not to turn crankshaft while removing crankshaft sprocket, as damage to valves and or pistons could occur.
- Remove crankshaft sprocket by first installing the crankshaft damper bolt. Apply grease or equivalent to damper bolt head and position Special Tools 5048-1, 5048-6, and 8539 (1) on sprocket and crankshaft nose. Remove sprocket using care not to rotate the crankshaft.
Scheme 761
Scheme 762
Scheme 763
Scheme 764
Scheme 765
Scheme 766
Scheme 767
- Inspect all sprockets (4),(9),(11) and chain guides (2),(5),(10). Replace if worn.
- For crankshaft sprocket installation procedures, see «Engine/Engine Block/CRANKSHAFT - Installation»(ref-353618-S21460297642010011200000) .
- If removed, install the right and left side short chain guides (10). Tighten attaching bolts to 28 N.m (250 in. lbs.).
- Align the crankshaft sprocket timing mark to the mark on the oil pump housing (3). NOTE: Lubricate timing chain and guides with engine oil before installation.
- Place the left side primary chain sprocket onto the chain so that the timing mark is located in between the two (plated) timing links (1).
- Lower the primary chain with the left side sprocket through the left cylinder head opening. NOTE: The camshaft sprockets can be allowed to float on the camshaft hub during installation.
- Loosely position the left side camshaft sprocket over the camshaft hub.
- Align the timing (plated) link to the crankshaft sprocket timing mark (3).
- Position the primary chain onto the water pump drive sprocket (11).
- Align the right camshaft sprocket timing mark to the timing (plated) link on the timing chain (8) and loosely position over the camshaft hub.
- Verify that all chain timing (plated) links are properly aligned to the timing marks on all sprockets.
- Install the left side lower chain guide (2) and tensioner arm (5). Tighten attaching bolts to 28 N.m (250 in. lbs.). NOTE: Inspect the O-ring on the chain guide access plugs before installing. Replace the O-ring as necessary.
- Install the chain guide access plugs to the cylinder heads. Tighten plugs to 20 N.m (15 ft. lbs.). NOTE: To reset the primary timing chain tensioner, engine oil will first need to be purged from the tensioner.
- Purge oil from the timing chain tensioner using the following procedure: Place the check ball (2) end of the tensioner into the shallow end of Chain Tensioner Gauge 8186 (3). Using hand pressure, slowly depress the tensioner until oil is purged from the tensioner.
- Reset the timing chain tensioner using the following procedure: Position the cylinder plunger (4) into the deeper end of Chain Tensioner Gauge 8186 (3). Apply a downward force until tensioner is reset. NOTE: If oil was not first purged from the tensioner, use slight finger pressure to assist the center arm pin of Chain Tensioner Gauge 8186 to unseat the tensioner's check ball. CAUTION: Ensure the tensioner is properly reset. The tensioner body (4) must bottom against the top edge of Chain Tensioner Gauge 8186 (3). Failure to properly perform the resetting procedure may cause tensioner jamming. NOTE: Inspect the tensioner O-ring (2) for nicks or cuts and make sure the snap ring (1) is correctly installed, replace as necessary.
- Install the reset chain tensioner (1) into the right cylinder head.
- Position tensioner retaining plate (2) and tighten bolts (3) to 12 N.m (105 in. lbs.).
- Starting at the right cylinder bank, first position the camshaft damper (1) (if equipped) on the camshaft hub, then insert a 3/8" square drive extension with a breaker bar into the intake camshaft drive hub. Rotate the camshaft until the camshaft hub aligns to the camshaft sprocket and damper attaching holes. Install the sprocket attaching bolts and tighten to 28 N.m (250 in. lbs.).
- Insert a 3/8" square drive extension with a breaker bar into the intake camshaft drive hub and rotate the camshaft until the sprocket attaching bolts can be installed. Tighten the sprocket bolts to 28 N.m (250 in. lbs.).
- Rotate the crankshaft slightly clockwise to remove timing chain slack, if necessary.
- Activate the timing chain tensioner by using a flat bladed pry tool to gently pry tensioner arm towards the tensioner slightly. Then release the tensioner arm. Verify the tensioner is activated (extends).
- Install the power steering pump and bracket assembly. Refer to «Steering/Pump - Installation»(ref-353572-S40988039922010011200000) .
- Install the camshaft position sensor and connect the electrical connector.
- Install the timing chain cover, crankshaft vibration damper, and accessory drive belts. See «Engine/Valve Timing/COVER(S), Engine Timing - Installation»(ref-353618-S03533396422010011200000) . 1 - DOUBLE ENDED STUDS 2 - BOLTS
- Install the cylinder head covers. See «Engine/Cylinder Head/COVER(S), Cylinder Head - Installation»(ref-353618-S21770656922010011200000) .
- Install the upper intake manifold and air cleaner housing assembly. See «Engine/Manifolds/MANIFOLD, Intake - Installation»(ref-353618-S18975037872010011200000)
- Connect the negative battery cable and tighten nut to 5 N.m (45 in. lbs.).
- Fill the cooling system. Refer to «Cooling - Standard Procedure»(ref-353584-S11330501202010011200000) . NOTE: After installation of a reset tensioner, engine noise will occur after initial start-up. This noise will normally disappear within 5-10 seconds.
- Operate the engine until it reaches normal operating temperature. Check cooling system for correct fluid level. Refer to «Cooling - Standard Procedure»(ref-353584-S11330501202010011200000) . NOTE: The Cam/Crank Variation Relearn procedure must be performed anytime there has been a repair/replacement made to a powertrain system, for example: flywheel, valvetrain, camshaft and/or crankshaft sensors or components. Refer to «DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure»(ref-353603-S03528494482010011200000) .
Scheme 768
| 1 - SPECIAL TOOL 6780-1 |
|---|
| 2 - SPECIAL TOOL 8179 |
Scheme 769
- Install crankshaft sprocket using Special Tools 6780-1 and 8179 (2) until sprocket bottoms against crankshaft step flange. Use care not to rotate crankshaft.
- Verify that crankshaft sprocket is installed to proper depth by measuring from sprocket outer face to end of crankshaft. Measurement should read: 39.05 ±0.50 mm (1.5374 ±0.020 in.).
- Install primary timing chain. See «Engine/Valve Timing/CHAIN and SPROCKETS, Timing - Installation»(ref-353618-S25049796892010011200000) .
Scheme 770
Scheme 771
- Disconnect and isolate negative battery cable.
- Drain cooling system.
- Remove coolant pressure container.
- Remove right front wheel and belt splash shield (2). 1 - GENERATOR 2 - IDLER/TENSIONER
- Remove accessory drive belts (2). Refer to «Cooling/Accessory Drive/BELT, Serpentine - Removal»(ref-353584-S03638748182010011200000) .
- Remove crankshaft vibration damper. See «Engine/Engine Block/DAMPER, Vibration - Removal»(ref-353618-S27047139172010011200000) .
- Remove AC/Generator belt tensioner/bracket assembly.
- Disconnect heater hose from tube at right front frame rail area.
- Remove screws securing heater supply tube to right frame rail. Reposition heater supply tube.
- Place a floor jack with wooden block under oil pan to support engine.
- Remove right engine mount.
- Remove upper timing chain cover bolts.
- Remove remaining bolts securing timing chain cover to engine.
- Remove timing chain cover (2).
- Discard timing chain cover gasket (1). Remove front crankshaft oil seal from cover.