Unit Repair

Engine Component Description

Engine Description

Cylinder Block
The cylinder block is an aluminum casting with four cast iron cylinder sleeves. The cylinder block has four in-line cylinders, which are numbered 1 through 4 starting from the crankshaft pulley. The cylinder block contains coolant jackets through which coolant flows around the cylinders, to cool the cylinder block and maintain a constant operating temperature.

Crankshaft
The crankshaft is cast nodular iron with eight counterweights. Oil holes run through the center of the crankshaft to supply oil to the connecting rods, bearings, pistons and other components. The end thrust load is taken by the thrust washers installed at the center number three bearing journal.

Connecting Rod and Piston
The connecting rods are forged steel, heat treated and shot peened. The connecting rod incorporates the full-floating type pin. The pistons are cast aluminum. The piston rings are of a low tension type to reduce friction. The top compression ring is plated with chromium for abrasion resistance. The second compression ring is gray iron. The oil ring is a piece spring construction.

Oil Pan
The oil pan is constructed of stamped steel and is mounted to the lower crankcase. The oil pan includes a baffle that helps prevent the oil from shifting away from the oil pump suction pipe during hard sums, acceleration or stopping.

Cylinder Head
The cylinder head is an aluminum casting with pressed-in valve guides and valve seat insets. The fuel injection nozzles are located in the intake ports.

Valves
There are No intake and TWC exhaust valves per cylinder. There are TWC valve springs per valve. Positive valve stem seals are used on all valves.

Camshaft
There is one camshaft that is used to operate all 16 valves. The camshaft is made of cast iron.

Camshaft Drive
The camshaft is belt driven and a mechanical tensioner is used to retain the proper timing belt tension.

Intake and Exhaust Manifold
The intake manifold is made of aluminum. The exhaust manifold is cast iron.

Lubrication Description





The lubrication system consists of an oil pan, oil pump screen, oil pump, oil filter and oil pressure regulator. This pressure-fed lubrication system supplies oil to the moving parts of the engine. The oil pump picks up oil from the oil pan and feeds it under pressure to the various parts of the engine. An oil strainer is mounted before the inlet to the oil pump to remove impurities, which could clog or damage the oil pump or other engine components. The oil pump itself is a trochoid gear type pump with internal drive and driven gears. When the drive rotates, the driven gear rotates in the same direction, but on a different center point. This causes the space between the gears to constantly open and narrow, pulling oil in from the oil pan when the space opens and pumping the oil out to the engine as it narrows. The oil filter is a full flow type with a relief valve built into the paper filter element. Contaminants, which can get into the oil during operation, could cause accelerated engine wear or seizing if allowed into the engine. The oil filter, situated at the beginning of the oil passage circuit, removes these contaminants as the oil passes through it. The relief valve spring will open under the pressure of the oil and allow oil to bypass the filter and flow directly to the engine.
At high engine speeds, the oil pump supplies a much higher amount of oil than required for lubrication of the engine. The oil pressure regulator prevents too much oil from entering the engine lubrication passages. During normal oil supply, a coil spring and valve keeps the bypass closed, directing all oil pumped to the engine. When the amount of oil being pumped increases, the pressure becomes high enough (420 kPa (60 psi)) to overcome the force of the spring, opening the valve and allowing excess oil to flow through the valve and drain back to the oil pan.
Oil is pumped from the oil pan by the oil pump. After it passes through the oil filter, it is fed through TWC paths to lubricate the cylinder block and cylinder head.
In one path, the oil is pumped through oil passages in the crankshaft to the connecting rods, then to the pistons and cylinders. It then drains back to the oil pan.
In the second path, the oil is pumped through passages to the camshaft and the hydraulic valve lash adjusters. The oil passes through internal passageways in the camshafts to lubricate the valve assemblies before draining back to the oil pan.

Cleanliness and Care
An automobile engine is a combination of many machined, honed, polished, and lapped surfaces with tolerances that are measured in ten thousandths of an inch. When any internal engine parts are serviced, care and cleanliness are important. A liberal coating of engine oil should be applied to friction areas during assembly to protect and lubricate the surfaces during initial operation. It should be understood that proper cleaning and protection of machined surfaces and friction areas are part of the repair procedure. This is considered standard shop practice even if not specifically stated.
When valve train components are removed for service, they should be retained in order. At the time of installation, they should be installed in the same locations and with the same mating surfaces as when removed.

Replacing Engine Gaskets

Gasket Reuse and Applying Sealants
- Do not reuse any gasket unless specified.
- Gaskets that can be reused will be identified in the service procedure.
- Do not apply sealant to any gasket or sealing surface unless called out in the service information.

Separating Components
- Use the proper prying points to separate components.
- Use caution when separating all RTV sealed components.

Cleaning Gasket Surfaces
- Remove all gasket and sealing material from the part.
- Care must be used to avoid gouging or scraping the sealing surfaces.
- Do not use any other method or technique to remove sealant or gasket material from a part.
- Do not use abrasive pads, sand paper, or power tools to clean the gasket surfaces.
- These methods of cleaning can cause damage to the component sealing surfaces.
- Abrasive pads also produce a fine grit that the oil filter cannot remove from the oil.
- This grit is abrasive and has been known to cause internal engine damage.

Assembling Components
- When assembling components, use only the sealant specified or equivalent in the service procedure.
- Sealing surfaces should be clean and free of debris or oil.
- Specific components such as crankshaft oil seals or valve stem oil seals may require lubrication during assembly.
- Components requiring lubrication will be identified in the service procedure.
- When applying sealant to a component, apply the amount specified in the service procedure.
- Do not allow the sealant to enter into any blind threaded holes, as it may prevent the bolt from clamping properly or cause component damage when tightened.
- Tighten bolts to specifications. Do not overtighten.

Use of RTV and Anaerobic Sealer

Pipe Joint Compound

Important: Three types of sealer are commonly used in engines. These are RTV sealer, anaerobic gasket eliminator sealer, and pipe joint compound. The correct sealer and amount must be used in the proper location to prevent oil leaks. DO NOT interchange the three types of sealers. Use only the specific sealer or the equivalent as recommended in the service procedure.

- Pipe joint compound is a pliable sealer that does not completely harden.
- Do not use pipe joint compound in areas where extreme temperatures are expected. These areas include: exhaust manifold, head gasket, or other surfaces where gasket eliminator is specified.
- Follow all safety recommendations and directions that are on the container.
- Apply the pipe joint compound to a clean surface. Do not allow the sealer to enter any blind i threaded holes, as it may prevent the bolt from clamping properly or cause component damage when the bolt is tightened.
/- Tighten the bolts to specifications. Do not overtighten.

RTV Sealer
- Room Temperature Vulcanizing (RTV) sealant hardens when exposed to air. This type sealer is used where TWC non-rigid parts (such as the intake manifold and the engine block) are assembled together.
- Do not use Room Temperature Vulcanizing (RTV) sealant in areas where extreme temperatures are expected. These areas include exhaust manifold, head gasket, or other surfaces where a gasket eliminator is specified.
- Follow all safety recommendations and directions that are on the container.
- Apply RTV to a clean surface. Use a bead size as specified in the procedure. Run the bead to the inside of any bolt holes. Do not allow the sealer to enter any blind threaded holes, as it may prevent the bolt from clamping properly or cause damage when the bolt is tightened.
- Assemble components while RTV is still wet (within 3 minutes). Do not wait for RTV to skin over.
- Tighten bolts to specifications. Do not overtighten.

Anaerobic Sealer
- Anaerobic gasket eliminator hardens in the absence of air. This type sealer is used where TWC rigid parts (such as castings) are assembled together. When TWC rigid parts are disassembled and no sealer or gasket is readily noticeable, the parts were probably assembled using a gasket eliminator.
- Follow all safety recommendations and directions that are on the container.
- Apply a continuous bead of gasket eliminator to one flange. Surfaces to be resealed must be clean and dry.
- Spread the sealer evenly with your finger to get a uniform coating on the sealing surface.
- Do not allow the sealer to enter any blind threaded holes, as it may prevent the bolt from clamping properly or cause damage when tightened.

Important: Anaerobic sealed joints that are partially torqued and allowed to cure more than five minutes may result in incorrect shimming and sealing of the joint.

Do not allow the sealer to enter any blind threaded holes, as it may prevent the bolt from seating properly or cause damage when the bolt is tightened.
- Tighten bolts to specifications. Do not overtighten.
- After properly tightening the fasteners, remove the excess sealer from the outside of the joint.

Tools and Equipment
Special tools (or their equivalents) are specially designed to quickly, and safely accomplish the operations for which they are intended. The use of these special tools will also minimize possible damage to engine components. Some precision measuring tools are required for inspection of certain critical components. Torque wrenches and a torque angle meter are necessary for the proper tightening of various fasteners.
To properly service the engine assembly, the following items should be readily available:
- Approved eye protection and safety gloves
- A clean, well-lit, work area
- A suitable parts cleaning tank
- A compressed air supply
- Trays or storage containers to keep parts and fasteners organized
- An adequate set of hand tools
- Approved engine repair stand
- An approved engine lifting device that will adequately support the weight of the components