Engine Preparation Description
New Product InformationThe purpose of New Product Information is to highlight or indicate important new features for the service community.
Changes may include one or more of the following items:
^ Torque values and/or fastener tightening strategies
^ Engine specifications
^ New sealants and/or adhesives
^ Disassembly and assembly procedure revisions
^ Engine mechanical diagnostic procedure revisions
^ Special tools required
New Sealants and/or Adhesives
^ U.S. and Canadian SPO part numbers
^ 3-Bond sealant P/N 12378521
New Features on the LL8 Engine
^ Pan-axle design oil pan
^ Exhaust camshaft position actuator
^ Exhaust camshaft position actuator valve
^ Jack bolts on the front cover, rear cover, and Oil pan
Engine Features
^ Powder metal connecting rods
^ Full floating piston pins
^ Lost foam casted aluminum block and head
^ Composite plastic camshaft cover
^ Electronic Throttle Control - ETC
^ Composite intake manifold
^ Bridge/bearing beam - stiffener ladder
^ Stainless steel fuel rail
^ Coil-on-plug ignition system
^ Inlet side thermostat
^ No EGR
^ No AIR
New Special Tools Required
- J 44217 Timing chain holding tool
- J 44218 Front seal installation tool
- J 44219 Cover alignment pins
- J 44220 Engine lift bracket
- J 44221 Camshaft holding tool
- J 44222 Camshaft actuator and sprocket holding tool
- J 44226 Crankshaft damper holding and removal tool
- J 22227 Rear main seal installation tool
Exhaust Camshaft Position Actuator Description
The camshaft position actuator is bolted to the front of the exhaust camshaft and is integral with the sprocket. The actuator and sprocket can only be replaced as one unit. The actuator has a hydraulically actuated piston located in the hub. The piston has an internal helical spline that slides in mesh with the gear. As the piston moves, the piston and gear mechanism changes the timing of the exhaust camshaft, relative to the cam drive sprocket. When oil pressure is applied to one side of the piston, the cam moves clockwise and timing is advanced. When oil pressure is applied to the other side of the piston the cam moves counter-clockwise to retard timing. The total range of actuator rotation is O to 25 camshaft degrees. At idle, the exhaust camshaft position actuator is at full advance or O degrees.
Lubrication Description
The engine lubrication system is of the force-feed type. The oil is supplied under full pressure to the crankshaft, connecting rods, and valve lash adjusters. A controlled volume of oil is supplied to the camshaft and valve rocker arms. Gravity flow or splash lubricates all other parts. The engine oil is stored in the oil pan, which is filled through a fill cap in the camshaft cover. A removable oil level indicator, on the right side of the engine block, is provided to check the oil level. The oil pump is located in the engine front cover and is driven by the crankshaft. It is a gerotor-style pump, which is a combination of a gear, and a rotor pump. It is connected by a passage in the cylinder block to an oil screen and pipe assembly. The screen is submerged in the oil supply and has ample volume for all operating conditions. Oil is drawn into the pump through the screen and pipe assembly, and a passage in the crankcase, connecting to the passages in the engine front cover. Oil is discharged from the oil pump to the oil filter. The oil pressure relief valve limits the oil pressure. The oil filter bypass valve opens when the oil filter is restricted to approximately 68.95 kPa (10 psi) of pressure difference between the oil filter inlet and discharge. The oil will then bypass the oil filter and channel unfiltered oil directly to the main oil galleries of the engine. A full-flow oil filter is mounted to the oil filter adapter on the lower right front side of the engine. The main oil galleries run the full length of the engine block and cut into the valve lash adjuster holes to supply oil at full pressure to the valve lash adjusters. Holes are drilled from the crankshaft bearings to the main oil gallery. Oil is transferred from the crankshaft bearings to the connecting rod bearings through holes drilled in the crankshaft.
Pistons, piston pins, and cylinder walls are lubricated by oil splash from the crankshaft and connecting rods. The camshafts and valve rocker arms are supplied with oil from the oil passages drilled into the camshaft mounting areas.
Separating Parts
The components of an internal combustion engine develop wear patterns with their mating components. During disassembly of the engine, parts should be separated and kept in order so they may be reinstalled in the same location from which they were removed.
Cleanliness and Care
An automobile engine is a combination of many of the following surfaces:
^ Machined
^ Honed
^ Polished
^ Lapped
The tolerances of these surfaces are measured in the ten-thousandths of an inch. When you service any internal engine part, cleanliness and care are important. Apply a liberal coating of engine oil to the friction areas during assembly in order to protect and lubricate the surfaces on initial operation. Practice proper cleaning and protection procedures to the machined surfaces and to the friction areas.
Notice: Engine damage may result if an abrasive paper. pad, or motorized wire brush is used to clean any engine gasket surfaces.
Whenever you remove the valve train components, keep the components in order. Follow this procedure in order to install the components in the same locations and with the same mating surfaces as when removed.
Caution: Refer to Battery Disconnect Caution in Service Precautions.
Disconnect the negative battery cables before you perform any major work on the engine.
Replacing Engine Gaskets
1. Do not reuse any gasket unless otherwise specified. Reusable gaskets will be identified in the service procedure. Do not apply sealant to any gasket or sealing surface unless called out in the service procedure.
2. Use a jack screws to separate components.
Important: Do not use any other method or technique in order to remove the gasket material from a components.
Do not use the following items in order to clean the gasket surfaces:
^ Abrasive pads
^ Sand paper
^ Power tools
These methods of cleaning may damage the component.
Abrasive pads also produce a fine grit that the oil filter cannot remove from the oil. This grit is abrasive and may cause internal engine damage.
3. Remove all of the gasket and the sealing material from the component using a plastic or a wood scraper. Do not gouge or scrape the sealing surfaces.
Important: Do not allow the sealant to enter any blind threaded holes. The sealant may cause the following conditions:
^ Prevent you from properly seating the bolt
^ Cause damage when you tighten the bolt
4. When assembling components, use only the sealant specified in the service procedure. Ensure that the sealing surfaces are clean and free of debris or oil. When applying sealant to a component, apply a bead size as specified in the service procedure.
5. Tighten the bolts to the specifications.
Use of RTV and Anaerobic Sealer
Sealant Types
Important: The correct sealant and amount of sealant must be used in the proper location to prevent oil leaks, coolant leaks, or the loosening of the fasteners. DO NOT interchange the sealants. Use only the sealant (or equivalent) as specified in the service procedure.
The following 2 major types of sealant are commonly used in engines:
^ Aerobic sealant (Room Temperature Vulcanizing (RTV))
^ Anaerobic sealant, which include the following:
- Gasket eliminator
- Pipe
- Threadlock
Aerobic Type Room Temperature Vulcanizing (RTV) Sealants
Aerobic type Room Temperature Vulcanizing (RTV) sealant cures when exposed to air. This type of sealant is used where 2 components (such as the intake manifold and the engine block are assembled together.
Use the following information when using RTV sealant:
^ Do not use RTV sealant subareas where extreme temperatures are expected. These areas include:
- The exhaust manifold.
- The head gasket
- Any other surfaces where a different type of sealant is specified in the service procedure
^ Always follow all the safety recommendations and the directions that are on the RTV sealant container.
^ Use a plastic or wood scraper in order to remove all the RTV sealant from the components.
Important: Do not allow the RTV sealant to enter any blind threaded holes, as it may prevent the fasteners from clamping properly or cause damage when the fastener is tightened.
^ The surfaces to be sealed :must be clean and dry.
^ Use a RTV sealant bead size as specified in the service procedure.
^ Apply the RTV sealant bead to the inside of any bolt holes areas.
^ Assemble the components while the RTV sealant is still wet to the touch. Do not wait for the RTV sealant to skin over.
^ Tighten the fasteners in sequence (if specified) and to the proper torque specifications. DO NOT overtighten the fasteners.
Anaerobic Type Threadlock Sealant
Anaerobic type threadlock sealant cures in the absence of air. This type of sealant is used for threadlocking and sealing of bolts, fittings, nuts, and studs. This type of sealant cures only when confined between 2 close fitting metal surfaces.
Use the following information when using threadlock sealant:
^ Always follow all safety recommendations and directions that are on the threadlock sealant container.
^ The threaded surfaces to be sealed must be clean and dry.
^ Apply the threadlock sealant as specified on the threadlock sealant container.
Important: Fasteners that are partially torqued and then the threadlock sealant allowed to cure more than five minutes, may result in incorrect clamp load of assembled components.
^ Tighten the fasteners in sequence (if specified) and to the proper torque specifications. DO NOT overtighten the fasteners.
Anaerobic Type Pipe Sealant
Anaerobic type pipe sealant cures in the absence of air and remains pliable when cured. This type of sealant is used where 2 parts are assembled together and require a leak proof joint.
Use the following information when using pipe sealant:
^ Do not use pipe sealant in areas where extreme temperatures are expected. These areas include:
- The exhaust manifold
- The head gasket
- Surfaces where a different sealant is specified
^ Always follow all the safety recommendations and the directions that are on the pipe sealant container.
^ The surfaces to be sealed must be clean and dry.
^ Use a pipe sealant bead of the size or quantity as specified in the service procedure.
Important: Do not allow the pipe sealant to enter any of the blind threaded holes, as the pipe sealant may prevent the fastener from clamping properly, or cause component damage when the fastener is tightened.
^ Apply the pipe sealant bead to the inside of any bolt hole areas.
^ Apply a continuous bead of pipe sealant to 1 sealing surface.
^ Tighten the fasteners in sequence (if specified) and to the proper torque specifications. DO NOT overtighten the fasteners.
Tools and Equipment
Work in a clean and well-lit area. Have the following components available before you begin to work:
^ A suitable parts cleaning tank
^ A compressed air supply
^ Trays, in order to keep the parts and the fasteners organized
^ An adequate set of hand tools
An approved engine repair stand will prevent personal injury or damage to the engine components. The special tools are designed in order to quickly and safely accomplish the operations for which the tools are intended. Using the tools will minimize possible damage to the engine components. Precision measuring tools are required for the inspection of certain critical components. Torque wrenches are needed for the correct assembly of various parts.