1993 Lexus ES300 Service & Repair Manual

ENGINE EG–1

ENGINE MECHANICAL DESCRIPTION EG0EF–01 The 3VZ–FE engine is a V–6, 3.0 liter, DOHC 24–valve engine. EG–2 – ENGINE TROUBLESHOOTING ENGINE MECHANICAL

The 3VZ–FE engine has 6 cylinder in a V arrangement at a bank angle of 60°. From the front of the RH bank cylinders are numbered 1–3–5, and from the front of the LH bank cylinders are numbered 2–4–6. The crankshaft is supported by 4 bearings inside the crankcase. These bearings are made of copper and lead alloy. The crankshaft is integrated with semi 9 counter weights for balance. Oil holes are placed in the center of the crankshaft for supplying oil to the connecting rods, pistons and other components. This engine’s firing order is 1–2–3–4–5–6. The cylinder head is made of aluminum alloy, with a cross flow type intake and exhaust layout and with pent–roof type combustion chambers. The spark plugs are located in the center of the combustion chambers. At the front and rear of the intake port of the intake manifold, a water passage has been provided which connects the RH and LH cylinder heads. Exhaust and intake valves are equipped with irregular pitch springs made of special valve spring carbon steel which are capable of functioning no matter what the engine speed. The RH and LH intake camshafts are driven by a single timing belt, and a gear on the intake camshaft engages with a gear on the exhaust camshaft to drive it. The camshaft journal is supported at 5 (intake) or 4 (exhaust) places between the valve lifters of each cylinder and on the front end of the cylinder head. Lubrication of the cam journals and gears is accomplished by oil being supplied through the oiler port in the center of the camshaft. Adjustment of the valve clearance is done by means of an outer shim type system, in which valve adjusting shims are located above the valve lifters. This permits replacement of the shims without removal of the camshafts. The timing belt cover is composed of the resin type No.2 and No.1 above and below the engine RH mounting bracket. Pistons are made of high temperature–resistant aluminum alloy, and a depression is built into the piston head to prevent interference with the valves. Piston pins are the full–floating type, with the pins fastened to neither the piston boss nor the connecting rods. Instead, snap rings are fitted on both ends of the pins, preventing the pins from falling out. The No.1 compression ring is made of steel and the No.2 compression ring is made of cast iron. The oil ring is made of a combination of steel and stainless steel. The outer diameter of each piston ring is slightly larger than the diameter of the piston and the flexibility of the rings allows them to hub the cylinder walls when they are mounted on the piston. Compression rings No.1 and No.2 work to prevent gas leakage from the cylinder and the oil ring works to clear oil off the cylinder walls to prevent it from entering the combustion chamber. The cylinder block is made of cast iron with a bank angle of 60°. It has 6 cylinders which are approximately 1.6 times the length of the piston stroke. The top of the cylinders is closed off by the cylinder heads and the lower end of the cylinders becomes the crankcase, in which the crankshaft is installed. In addition, the cylinder block contains a water jacket, through which engine coolant is pumped to cool the cylinders. The oil pan is bolted onto the bottom of the cylinder block. The oil pan is an oil reservoir made of pressed steel sheet. – ENGINE TROUBLESHOOTING ENGINE MECHANICAL EG–3

PREPARATION SST (SPECIAL SERVICE TOOLS) EG0EG–01 EG–4 – ENGINE TROUBLESHOOTING ENGINE MECHANICAL

– ENGINE TROUBLESHOOTING ENGINE MECHANICAL EG–5

1993 Lexus ES300 Service & Repair Manual

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