3.0L V6: Diagnosis Lexus RX I

TROUBLE SHOOTING

To trouble shoot engine mechanical components, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

Inspection

1. Inspect cylinder head warpage at cylinder block and manifold areas. Replace cylinder head if warpage exceeds specification. See «CYLINDER HEAD»(ref-4442-S38457892172000062700000) table under ENGINE SPECIFICATIONS.
2. Inspect air intake chamber-to-intake manifold surface and exhaust manifold for warpage. Inspect intake manifold-to-cylinder head and air intake chamber surfaces for warpage. Replace components if warpage exceeds specification. See «WARPAGE SPECIFICATIONS»(ref-4442-S24420067362000062700000) table. WARPAGE SPECIFICATIONS Application In. (mm) Air Intake Chamber .0039 (.100) Exhaust Manifold .0196 (.498) Intake Manifold Air Intake Chamber Surface .0059 (.150) Cylinder Head Surface .0031 (.079)
3. Using caliper, measure 12-point cylinder head bolt diameter, just below bolt head. Replace cylinder head bolt if diameter is less than .3445" (8.750 mm).
4. Inspect cylinder block deck surface for warpage. Replace cylinder block if deck surface warpage exceeds specification. See «CYLINDER BLOCK»(ref-4442-S35243638062000062700000) table under ENGINE SPECIFICATIONS. Inspect camshaft and components. See «CAMSHAFT»(ref-4442-S30780122482000062700000) .
5. Inspect valve lifter for damage. Measure valve lifter diameter and bore diameter. Ensure oil clearance is within specification. Replace components if not within specification. See «VALVE LIFTERS»(ref-4442-S19478503212000062700000) table under ENGINE SPECIFICATIONS.

Scheme 8

Scheme 9

Scheme 10

1. Install NEW cylinder head gaskets on cylinder block. Ensure identification mark faces in correct direction. (Scheme 8) Ensure all holes in cylinder head gaskets align with cylinder block.
2. Install cylinder head. Apply engine oil onto cylinder head bolt threads and cylinder head bolt-to-cylinder head contact surfaces. Install plate washers on bolts. Install and tighten 12-point cylinder head bolts to specification in sequence using several passes. see scheme 15 See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000).
3. Reference mark front cylinder head bolt head. Retighten cylinder head bolts to 90 degrees. Ensure painted mark is positioned at 90-degree angle. (Scheme 9)
4. Install recessed cylinder head bolts and tighten to specification. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000). Install camshafts using proper procedure. See «CAMSHAFT»(ref-4442-S30780122482000062700000).
5. If new cylinder head is installed, spark plug tubes must be replaced. Apply 3 bond adhesive to end of tubes. Press in spark plug tubes until tubes protrude 1.669-1.709" (42.2-43.4 mm) above cylinder head.
6. Remove old packing material. Apply sealant to grooves of semi-circular plugs and install 2 semi-circular plugs to cylinder head. Install and tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000).
7. Before installing valve cover and gasket, apply sealant at front and rear areas of cylinder head. see scheme 7 Using NEW gasket, install valve cover. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000).
8. To install remaining components, reverse removal procedure. If camshaft or cylinder head components are serviced, adjust valve clearance. See «VALVE CLEARANCE ADJUSTMENT»(ref-4442-S32984856982000062700000) under ADJUSTMENTS. When installing intake manifold delivery pipe and injectors, tighten bolts and nuts in several passes in sequence. (Scheme 10) Tighten to specification. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000). Fill engine with oil and coolant. Check for leaks.

1. Inspect timing belt for damaged teeth, cracking or oil contamination. Ensure idler pulleys rotate freely. Replace damaged components.
2. Inspect timing belt tensioner for signs of oil leakage. NOTE: Timing belt tensioner may weep a small amount of oil on rod seal under normal conditions. If excessive amount of oil exists, replace timing belt tensioner.
3. Hold timing belt tensioner body with rod facing upward and press rod against solid surface. Replace timing belt tensioner if rod moves.
4. Measure timing belt tensioner rod protrusion from end of rod to edge of timing belt tensioner housing. (Scheme 11) Replace timing belt tensioner if distance is not.394-.425" (10.01-10.80 mm).

Scheme 11

Inspect components for damage. Measure valve lifter diameter and bore diameter. Ensure oil clearance is within specification. Replace components if not within specification. See VALVE LIFTERS table under ENGINE SPECIFICATIONS.

1. Inspect components for damage. Check camshaft journal diameter, lobe height and journal runout. Replace camshaft if not within specification. See «CAMSHAFT»(ref-4442-S20852273572000062700000) table under ENGINE SPECIFICATIONS.
2. Install camshaft in cylinder head. Using Plastigage, check camshaft oil clearance. Tighten camshaft bearing cap bolts to specification in sequence when checking oil clearance. DO NOT rotate camshaft. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000) .
3. Remove bearing caps and measure Plastigage. 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. Install both camshafts without sub-gear installed on exhaust camshaft. Tighten camshaft bearing cap bolts to specification. Check gear backlash between camshaft gears.
6. Replace camshaft if gear backlash exceeds specification. See «CAMSHAFT»(ref-4442-S20852273572000062700000) table under ENGINE SPECIFICATIONS. Measure distance between ends of gear spring. Replace gear spring if distance between ends of gear spring is not .712-.740" (18.08-18.80 mm).

Scheme 12

Scheme 13

1. If reassembling exhaust camshaft, install gear spring so ends contact pins on main gear and sub-gear. see scheme 27 Install gear spring, camshaft sub-gear, wave washer and snap ring. Using spanner wrench, rotate sub-gear counterclockwise until holes in main gear and sub-gear are aligned. Install service bolt "A". see scheme 26
2. Apply engine oil to thrust surfaces and journals of camshafts. Install exhaust camshaft in cylinder head. Rotate exhaust camshaft so timing marks (2 dots) on right cylinder head, or (1 dot) on left cylinder head are positioned at 90-degree angle to cylinder head. (Scheme 12)
3. Apply grease to seal lip on NEW oil seal. Install oil seal on exhaust camshaft. Apply sealant on No. 1 exhaust camshaft bearing cap at bearing cap-to-cylinder head surface.
4. Install exhaust camshaft bearing caps in numerical order. Ensure arrow on top of camshaft bearing cap is pointing toward timing belt end of engine. (Scheme 13)
5. Coat camshaft bearing cap bolt-to-camshaft bearing cap surface and bolt threads with engine oil. Install and tighten exhaust camshaft bearing cap bolts to specification in sequence using several steps. (Scheme 14) See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000).
6. When installing intake camshaft in cylinder head, rotate camshafts so timing marks align (2 dots on right cylinder head, 1 dot on left cylinder head). see scheme 24
7. Install intake camshaft bearing caps in numerical order. Ensure arrow on top of camshaft bearing cap is pointing toward timing belt end of engine. (Scheme 13)
8. Coat camshaft bearing cap bolt-to-camshaft bearing cap surface, and bolt threads with engine oil. Install and tighten intake camshaft bearing cap bolts to specification in sequence using several steps. (Scheme 14) See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000). CAUTION: Ensure service bolt "A" is removed from sub-gear on exhaust camshafts.
9. Remove service bolt "A" from exhaust camshaft. Check and adjust valve clearance. See «VALVE CLEARANCE ADJUSTMENT»(ref-4442-S32984856982000062700000) under ADJUSTMENTS.
10. Apply sealant to grooves of semi-circular plugs and install in cylinder head (if removed). Before installing valve cover and gasket, apply sealant at front and rear areas of cylinder head. see scheme 7
11. Using NEW gasket, install valve cover. Install and tighten valve cover bolts to specification in several steps. See «TORQUE SPECIFICATIONS»(ref-4442-S26673951792000062700000). To install remaining components, reverse removal procedure using NEW gaskets. Tighten all fasteners to specification. Fill cooling system and adjust control cables.

Scheme 14

1. Inspect components for damage. Coat relief valve with engine oil. Ensure relief valve slides freely in bore on oil pump body. Install drive and driven rotors in oil pump body. Ensure both rotors are installed in oil pump body with identification mark (triangle mark) facing oil pump body cover.
2. Using feeler gauge, measure driven rotor-to-oil pump body clearance. Replace rotor assembly or oil pump body if clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-4442-S15502741222000062700000) table.
3. Using feeler gauge, measure clearance between tip of both rotors. Replace rotor assembly if clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-4442-S15502741222000062700000) table.
4. Place straightedge across oil pump body, above both rotors. Using feeler gauge, measure rotor end clearance between straightedge and rotor surface. Replace rotor assembly or oil pump body if clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-4442-S15502741222000062700000) table.

OIL PUMP SPECIFICATIONS