Engine: Removal & Installation Lexus SC I

Installation

1. To install, reverse removal procedure. Install NEW nuts when installing exhaust pipe components. Ensure reference marks on drive shaft companion flanges are aligned. CAUTION: Install intermediate drive shaft center bearing so bracket on center bearing is parallel to drive shaft.
2. Tighten fasteners to specification. See «TORQUE SPECIFICATIONS»(ref-49348-S39745954772001011500000) . Adjust fluid levels, control cables and shift linkage (if necessary).

Removal

1. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-49348-S03416196482001011500000). Disconnect negative battery cable. Disconnect control cables at throttle body. Remove air intake hose assembly with airflow meter and air cleaner. Remove EGR pipe. Drain cooling system.
2. Remove support brace located below throttle body. Disconnect PCV hose, necessary coolant hoses, vacuum hoses and electrical connectors for air intake connector and throttle body removal. Remove bolts/nuts and air intake connector with throttle body and gasket. (Scheme 10)
3. Place reference mark on fan clutch and water pump for reassembly reference. Remove drive belt, cooling fan, fan clutch and water pump pulley.
4. Disconnect necessary coolant hoses, vacuum hoses, electrical connectors, vacuum switching valves and vacuum pipes. Remove heater coolant control valve from firewall (if equipped). Remove EGR valve and vacuum modulator.
5. Remove oil filler cap and No. 3 (top cover) timing belt cover. Remove cylinder head rear cover located above valve covers. Disconnect spark plug wires from spark plugs. Remove spark plugs.
6. Rotate crankshaft clockwise so cylinder No. 1 (front cylinder) is at TDC on compression stroke. Ensure timing mark on crankshaft pulley aligns with "0" mark on timing belt cover. Remove nut and distributor.
7. Remove timing belt and camshaft sprockets. See TIMING BELT. Raise and support vehicle. Remove lower engine cover (if equipped). Disconnect electrical connector for oxygen sensor and sub-oxygen sensor (if equipped) mounted in exhaust pipe.
8. Disconnect exhaust pipe at exhaust manifolds. Remove heat insulator, nuts, No. 1 and No. 2 exhaust manifolds, and gaskets. Remove coolant by-pass outlet, coolant by-pass pipe, coolant outlet and by-pass hose. (Scheme 10) Remove nuts and vacuum valve set.
9. Remove power steering pump (if necessary) with hoses attached, and secure aside. Remove oil dipstick and dipstick tube. On A/T models, remove transmission dipstick and dipstick tube.
10. On all models, remove bolts/nuts and intake manifold braces. (Scheme 10) Remove bolts/nuts, air intake chamber and gasket.
11. Place suitable container under No. 1 fuel pipe union bolt at delivery pipe. (Scheme 10) Cover fuel pipe union bolt with shop towel.
12. Slowly loosen fuel line union bolt to release any residual fuel pressure. Remove union bolt and gaskets. Separate No. 1 fuel pipe from delivery pipe. Remove union bolt, and separate No. 2 fuel pipe from fuel pressure regulator on delivery pipe. CAUTION: DO NOT allow fuel injectors to fall from delivery pipe during removal.
13. Disconnect electrical connectors from fuel injectors. Remove bolts, delivery pipe, fuel injectors, spacers and insulators.
14. Remove bolts/nuts, intake manifold and gasket. Remove bolts/nuts, valve covers and gaskets. Remove bolts and No. 4 timing belt cover. (Scheme 10)
15. Remove bolts from No. 1 (front) camshaft bearing cap on each camshaft. Using screwdriver, carefully pry No. 1 camshaft bearing cap upward from cylinder head and remove. DO NOT damage sealing surfaces. Remove oil seal from camshaft. CAUTION: Camshaft bearing cap bolts must be removed in proper sequence to prevent damage to cylinder head and camshaft thrust surfaces.
16. Remove camshaft bearing cap bolts in sequence using several steps. see scheme 18 Remove camshaft bearing caps and camshaft. Note location of adjusting shims and valve lifters. Remove adjusting shims and valve lifters from cylinder head (if necessary). CAUTION: Cylinder head bolts must be loosened in proper sequence to prevent cylinder head warpage.
17. Loosen cylinder head bolts in sequence using several steps. (Scheme 11) Remove cylinder head bolts, cylinder head and cylinder head gasket.

Note. If cylinder head removal is difficult, carefully pry between cylinder head and projected area near front of cylinder block. DO NOT damage sealing surfaces on cylinder block and cylinder head.

Scheme 10

Scheme 11

1. Using NEW gasket, install EGR cooler (if removed). Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49348-S39745954772001011500000). Install cylinder head gasket (ensure gasket is installed correctly).
2. Install cylinder head. Apply light coat of oil to threads and underside of cylinder head bolts. Install cylinder head bolts and tighten to specification in sequence using several steps. (Scheme 11) See «TORQUE SPECIFICATIONS»(ref-49348-S39745954772001011500000).
3. Install camshafts. See «CAMSHAFT»(ref-49348-S39293887152001011500000). Check and adjust valve clearance. See «VALVE CLEARANCE ADJUSTMENT»(ref-49348-S41125009782001011500000) under ADJUSTMENTS.
4. Install No. 4 timing belt cover. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49348-S39745954772001011500000). Install camshaft sprockets and timing belt.
5. To install remaining components, reverse removal procedure using NEW gaskets and "O" rings. Use NEW nuts when installing exhaust manifold. Tighten bolts/nuts to specification. See «TORQUE SPECIFICATIONS»(ref-49348-S39745954772001011500000).
6. Before installing gaskets and valve covers, apply sealant at indicated areas on front of cylinder head. see scheme 4
7. If fuel injector was removed from delivery pipe, coat NEW "O" ring with gasoline. Install NEW "O" ring(s) and grommet(s) on fuel injector. Using twisting motion, install fuel injector in delivery pipe.
8. Install delivery pipe insulators and spacers on intake manifold. Install fuel injectors and delivery pipe. Ensure electrical connections on fuel injectors are facing upward, toward top of engine.
9. Loosely install bolts in delivery pipe. Ensure fuel injectors rotate smoothly with delivery pipe installed. If fuel injectors do not rotate smoothly, check for damaged "O" ring. Tighten delivery pipe bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49348-S39745954772001011500000).
10. Support braces are marked with an "F" or "R". When installing support braces on air intake chamber, ensure support brace marked "F" goes to the front (timing belt side) and support brace marked "R" goes to flywheel/drive plate side.
11. Ensure air intake connector gasket is installed with protrusion in proper location. see scheme 5 Install NEW "O" ring on distributor. Coat "O" ring with engine oil.
12. When installing distributor, rotate crankshaft clockwise so cylinder No. 1 (front cylinder) is at TDC on compression stroke. Ensure timing mark on crankshaft pulley aligns with "0" mark on timing belt cover.
13. Align reference mark on distributor gear with groove on distributor housing. (Scheme 12) Install distributor so bolt on cylinder head aligns with center of distributor flange. Install distributor bolt. Adjust fluid levels, control cables and ignition timing.

Scheme 12