3.0L V6: Other Lexus RX I

FUEL PRESSURE RELEASE

With ignition off, disconnect negative battery cable. Place suitable container under fuel line. Cover fuel line connection with shop towel. Slowly loosen fuel line connection to release fuel pressure. Once fuel pressure is released, fuel system components may be serviced.

ENGINE

Note. Remove engine and transaxle as an assembly.

CYLINDER HEAD & MANIFOLDS

CAMSHAFT

Note. When servicing camshafts, reference to right and left components are as viewed from rear of engine.

Scheme 31

Scheme 32

Scheme 33

Scheme 34

1. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-4442-S22239184532000062700000). Drain cooling system. On RX300, remove outer cowl top panel. On all models, remove right fender apron seal. Remove generator drive belt. Remove power steering pump. Remove front exhaust pipe.
2. Using 5-mm hexagon wrench remove 3 cap nuts from "V" bank cover and remove "V 'bank cover. Remove air cleaner cap and airflow meter with air cleaner hose. Remove cruise control actuator and bracket. Disconnect necessary electrical connections, ground straps, coolant hoses, fuel lines and vacuum hoses for removal of air intake chamber. Remove 2 bolts and No. 1 engine hangar.
3. Remove nuts and air intake chamber located above intake manifold. see scheme 13 Disconnect fuel injector connectors. Disconnect fuel inlet hose from fuel filter. Disconnect heater hose from intake manifold. Remove bolts, nuts and washer from intake mainfold and remove intake mainfold, fuel pipes and fuel injectors as an assembly. CAUTION: DO NOT allow injectors to fall from delivery pipe when removing from intake manifold.
4. Disconnect Engine Cooling Temperature (ECT) sensor and sending unit. Disconnect ground strap connector. Disconnect upper radiator hose. Disconnect engine coolant reservoir hose. Remove bolts, nuts and plate washers. Disconnect water by-pass hose, and remove thermostat housing. Remove 2 gaskets.
5. Remove ignition coils and spark plugs. Mark ignition coil location for reassembly reference. Remove timing belt, camshaft sprockets and No. 2 idler pulley. See «TIMING BELT»(ref-4442-S41089217502000062700000). Disconnect 3 engine wire clamps from timing belt cover. Remove 6 bolts and No. 3 timing belt cover.
6. Remove camshaft position sensors. Remove camshaft timing oil control valves. Remove nut, and disconnect engine wire protector from right cylinder head. Disconnect engine wire protector from left cylinder head. Remove 2 bolts and remove rear plate from left cylinder head. Disconnect water inlet pipes from left cylinder head. Remove "O" ring from inlet pipe.
7. Remove power steering pump bracket from front of cylinder head. Disconnect airflow sensor connector, remove bolt and nut and remove right exhaust manifold stay. Remove 6 nuts, right exhaust manifold and gasket. Repeat procedure for left exhaust manifold.
8. Remove bolt holding oil dipstick guide to left cylinder head. Pull out dipstick guide with dipstick from No. 1 oil pan. Remove "O" ring from dipstick guide. Remove 9 bolts, cylinder head cover and gasket. see scheme 14 Remove 2 cylinder head covers.
9. To remove right-side camshafts, align timing marks (2 dots) on camshaft gears by rotating intake camshaft using hexagonal area of camshaft. To remove left camshafts, align timing marls (1 dot) on camshaft gears by rotating intake camshaft using hexagonal area of camshaft. (Scheme 31)
10. On exhaust camshafts, secure sub-gear on exhaust camshaft to main gear with 6 x 1.0 x 20 mm service bolt "A". (Scheme 32) Before removing camshaft bearing cap bolts, ensure torsional spring force of sub-gear is held by service bolt "A".
11. Remove intake camshaft bearing cap bolts in sequence using several steps. (Scheme 35) Remove camshaft bearing caps and intake camshaft. CAUTION: Camshaft bearing cap bolts must be removed in proper sequence to prevent damage to cylinder head and camshaft thrust surfaces.
12. Remove exhaust camshaft bearing cap bolts in sequence using several steps. (Scheme 35) Remove camshaft bearing caps, exhaust camshaft and oil seal.
13. If disassembling exhaust camshaft gear, mount hexagonal area of camshaft in soft-jaw vise. Using Spanner Wrench (SST 09960-10010), rotate sub-gear counterclockwise and remove service bolt "A". (Scheme 33) Remove snap ring, wave washer, sub-gear and gear spring. (Scheme 34)

Scheme 35

Cylinder Head

1. Inspect cylinder head warpage at cylinder block and manifold surfaces. Replace cylinder head if warpage exceeds specification. See «CYLINDER HEAD»(ref-4442-S38457892172000062700000) table under ENGINE SPECIFICATIONS.
2. Using Plastigage, check camshaft oil clearance. Install camshaft in cylinder head. Tighten camshaft bearing caps using proper tightening sequence. see scheme 31
3. Replace camshaft and/or cylinder head if oil clearance is not within specification. See «CAMSHAFT»(ref-4442-S20852273572000062700000) table under ENGINE SPECIFICATIONS.
4. Check camshaft end play with camshaft bearing cap bolts tightened to specification. Replace camshaft and/or cylinder head if end play is not within specification. See «CAMSHAFT»(ref-4442-S20852273572000062700000) table under ENGINE SPECIFICATIONS.
5. Ensure valve lifter bore diameter is within specification. See «VALVE LIFTERS»(ref-4442-S19478503212000062700000) table under ENGINE SPECIFICATIONS.
6. If installing spark plug tubes in new cylinder head, apply sealant on cylinder head end of spark plug tube. Using press, install spark plug tube until distance between top surface of spark plug tube and camshaft bearing cap surface of cylinder head is 1.669-1.709" (42.40-43.40 mm).
7. If installing PCV pipe in new cylinder head, use hammer and wooden block. PCV pipes are installed between exhaust camshaft and outer edge of cylinder head. Install PCV pipe until top of pipe is even with valve cover gasket surface on cylinder head.

Valve Springs

Ensure valve spring free length, pressure and out-of-square are within specification. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS.

Valve Stem Oil Seals

Intake valve stem oil seal is Light Brown, and exhaust valve stem oil seal is Gray. Lubricate valve stem oil seal with engine oil. Install valve stem oil seal using Oil Seal Installer (SST 09201-41020).

Valve Guides

1. Ensure valve guide inside diameter is within specification. See «CYLINDER HEAD»(ref-4442-S38457892172000062700000) table under ENGINE SPECIFICATIONS. Replace valve guide if inside diameter exceeds specification.
2. To replace valve guide, heat cylinder head to 176-212°F (80-100°C). Using hammer and Valve Guide Remover/Installer (SST 09201-01055), drive valve guide from camshaft side of cylinder head.
3. Measure cylinder head valve guide bore inside diameter. If bore inside diameter is .4053-.4060" (10.295-10.312 mm), use standard valve guide. If bore inside diameter is .4073-.4080" (10.345-10.363 mm), use oversize valve guide.
4. If bore inside diameter exceeds .4060" (10.313 mm), machine valve guide bore to .4073-.4080" (10.345-10.363 mm) for oversize valve guide. If bore I.D. exceeds .4080" (10.363 mm), replace cylinder head. CAUTION: Exhaust valve guide is 1.594" (40.50 mm) long and intake valve guide is 1.358" (34.49 mm) long. Ensure proper length valve guide is installed.
5. To install valve guide, heat cylinder head to 176-212°F (80-100°C). Using hammer and valve guide remover/installer, drive valve guide in from camshaft side of cylinder head until valve guide installed height is within specification. See «CYLINDER HEAD»(ref-4442-S38457892172000062700000) table under ENGINE SPECIFICATIONS. Valve guide installed height is measured from top of valve guide to cylinder head surface, right next to valve guide.
6. Using .216" (5.48 mm) reamer, ream valve guide to obtain specified valve stem-to-guide oil clearance. See «CYLINDER HEAD»(ref-4442-S38457892172000062700000) table under ENGINE SPECIFICATIONS.

Valve Seat

Ensure valve seat angle and seat width are within specification. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. Valve seat replacement information is not available from manufacturer.

Valves

Ensure minimum refinish length, stem diameter and valve margin are within specification. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS. Replace valve if not within specification.

Valve Seat Correction Angles

Use 30-degree and 45-degree stones to lower valve seat contact area. Use 75-degree and 45-degree stones to raise valve seat contact area.

Valve Lifters

Ensure valve lifter diameter, bore diameter and oil clearance are within specification. See VALVE LIFTERS table under ENGINE SPECIFICATIONS. Replace components if not within specification.

Using "V" blocks and dial indicator, check camshaft runout. Ensure camshaft journal diameter and out-of-round are within specification. See CAMSHAFT table under ENGINE SPECIFICATIONS. Replace camshaft if not within specification.

Fitting Pistons

1. To determine piston-to-cylinder clearance, measure piston skirt diameter at .913" (23.20 mm) from top of piston at 90-degree angle to piston pin.
2. Ensure piston diameter is within specification. See «PISTONS, PINS & RINGS»(ref-4442-S02625586632000062700000) table under ENGINE SPECIFICATIONS.
3. Measure cylinder bore diameter at .39" (10.0 mm) from top and bottom of cylinder bore and at middle of cylinder bore. Ensure cylinder bore diameter is within specification. See «CYLINDER BLOCK»(ref-4442-S35243638062000062700000) table under ENGINE SPECIFICATIONS.
4. Determine piston-to-cylinder clearance. Replace piston or cylinder block if clearance is not within specification. See «PISTONS, PINS & RINGS»(ref-4442-S02625586632000062700000) table under ENGINE SPECIFICATIONS.

Piston Rings

Ensure piston ring end gap and side clearance are within specification. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS. Position piston rings with ring end gaps in proper areas with identification mark on piston ring toward top of piston. (Scheme 36)

Note. No. 1 compression ring may contain a 1R or "T" identification mark and No. 2 compression ring may contain a 2R or 2T identification mark. Ensure proper ring is installed in correct location.

Scheme 36

Scheme 37

1. Ensure connecting rod and connecting rod cap are marked with matching cylinder number for reassembly reference. Piston and connecting rod must be installed in cylinder block with front mark facing timing belt end of engine. see scheme 34
2. Connecting rod and back of rod bearing are stamped with size mark ("1", "2", "3" or "4"). (Scheme 37) Size marks on connecting rod and rod bearing must be the same. Rod bearing thickness is determined by size mark. See «ROD BEARING SPECIFICATIONS»(ref-4442-S03110761152000062700000) table. NOTE: If replacing rod bearing, ensure size mark on replacement rod bearing is the same as size mark on original rod bearing. Ensure size mark is also the same as that stamped on connecting rod.
3. Use caliper to measure outside diameter of connecting rod bolt, just above threads. Replace connecting rod bolt if outside diameter is less than.276" (7.01 mm).
4. Ensure piston and connecting rod are installed in cylinder block with front mark facing timing belt end of engine. Ensure protrusion on connecting rod cap is facing timing belt end of engine. see scheme 34
5. Coat threads and bolt head-to-connecting rod cap contact surface on connecting rod bolts with engine oil before tightening to specification. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000).
6. Ensure bearing oil clearance and connecting rod side play are within specification. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-4442-S37094700732000062700000) and «CONNECTING RODS»(ref-4442-S16672657962000062700000) tables under ENGINE SPECIFICATIONS.

ROD BEARING SPECIFICATIONS

Scheme 38

Scheme 39

Scheme 40

1. Remove main bearing cap side bolts (hexagon bolts) from side of cylinder block in sequence. Perform STEP 1 in illustration. (Scheme 38) Remove main bearing caps side bolts and seal washers.
2. Remove main bearing cap-to-cylinder block bolts (12-point bolts) from cylinder block in sequence. Perform STEP 2 in illustration. (Scheme 38)
3. Note location of main bearing caps. Main bearing caps are numbered on top of cap for location with No. 1 at timing belt end of engine and No. 4 at drive plate end. Arrow on top of main bearing cap must point toward timing belt end of engine. Remove main bearing caps, crankshaft, main bearings and thrust bearings.
4. Cylinder block main bearing bore inside diameter is determined by size mark stamped on front of cylinder block. (Scheme 39) Left size mark indicates No. 1 main bearing bore and far right size mark indicates No. 4 main bearing bore.
5. Crankshaft journal diameter is identified by size mark located on crankshaft counterweight. (Scheme 39) Ensure journal diameter, taper and out-of-round are within specification. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-4442-S37094700732000062700000) table under ENGINE SPECIFICATIONS.
6. Main bearing size mark is located on side of main bearing. (Scheme 39) If replacing main bearing, ensure size mark on replacement main bearing is the same as size mark on original main bearing.
7. If size mark on original main bearing cannot be obtained, use size marks on cylinder block and crankshaft to determine size mark of main bearing to be used. (Scheme 40) Main bearing thickness is identified by size mark on back of bearing. See «MAIN BEARING SPECIFICATIONS»(ref-4442-S27096947132000062700000) table. MAIN BEARING SPECIFICATIONS Size Mark Bearing Thickness - In. (mm) "1".0979-.0980 (2.486-2.489) "2".0980-.0981 (2.489-2.492) "3".0981-.0982 (2.492-2.495) "4".0982-.0983 (2.495-2.498) "5".0983-.0985 (2.498-2.501) "6".0985-.0986 (2.501-2.504) "7".0986-.0987 (2.504-2.507)
8. Use Plastigage to check main bearing oil clearance. Coat threads of main bearing bolts and bolt head-to-main bearing cap area with engine oil. Install wide main bearings in No. 1 and 4 positions, and narrow main bearings in No. 2 and 3 bearing locations.
9. Ensure all main bearings installed in cylinder block contain oil holes. Lower main bearings, installed in main bearing caps, do not have oil holes.
10. Install thrust bearings on No. 2 main bearing in cylinder block and main bearing cap with grooved sides facing outward, toward crankshaft. Install crankshaft and main bearing caps. CAUTION: Main bearing caps must be installed with arrow on top of cap pointing toward timing belt end of engine. Ensure main bearing caps are installed in numerical order, with No. 1 at timing belt end of engine and No. 4 at drive plate end.
11. Install and tighten main bearing cap-to-cylinder block bolts (12-point bolts) to specification in sequence using several steps. Perform STEP 1 in illustration. (Scheme 41) See «TORQUE SPECIFICATIONS»(ref-4442-S07642558372000062700000). NOTE: NEW seal washers must be installed on main bearing cap side bolts (hexagon bolts) during final assembly.
12. Install and tighten main bearing cap side bolts (hexagon bolts) to specification in sequence using several steps. Perform STEP 2 in illustration. (Scheme 41) See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000).
13. Check crankshaft end play using a dial indicator while prying crankshaft forward and rearward. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-4442-S37094700732000062700000) table under ENGINE SPECIFICATIONS. Replace thrust bearing if crankshaft end play is not within specification.

Scheme 41

Cylinder Block

1. Inspect cylinder block deck surface warpage. Replace cylinder block if deck warpage exceeds specification. See «CYLINDER BLOCK»(ref-4442-S35243638062000062700000) table under ENGINE SPECIFICATIONS.
2. Measure cylinder bore diameter at .39" (10.0 mm) from top and bottom of cylinder bore and at middle of cylinder bore. Replace cylinder block if cylinder bore diameter is not within specification. See «CYLINDER BLOCK»(ref-4442-S35243638062000062700000) table under ENGINE SPECIFICATIONS.
3. Ensure main bearing bore inside diameter is within specification with main bearing caps installed and bolts tightened to specification. See «CYLINDER BLOCK»(ref-4442-S35243638062000062700000) table under ENGINE SPECIFICATIONS. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000) .

Note. Main bearing bore inside diameter is determined by size mark stamped on front of cylinder block. (Scheme 39)

Oil Pressure

With engine at normal operating temperature, oil pressure should be at least 4.3 psi (0.3 kg/cm 2 ) at idle, and 43-78 psi (3.0-5.5 kg/cm 2 ) at 3000 RPM.