Engine Mechanical (4.7L V8): Diagnosis Lexus LX J100

TROUBLE SHOOTING

To trouble shoot mechanical engine 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-3005-S33687734702000041700000) table under ENGINE SPECIFICATIONS.
2. Using caliper, measure outside diameter of cylinder head bolts on threaded area 2.95-3.35" (75.0-.85.0 mm) downward from bottom of bolt head. Standard diameter should be .3862-.3921" (9.810-9.960). Replace cylinder head bolt if outside diameter is less than .3819" (9.700 mm).
3. Inspect upper intake manifold-to-lower intake manifold surface on upper intake manifold for warpage. Replace upper intake manifold if warpage exceeds .0059" (.150 mm).
4. Inspect lower intake manifold-to-upper intake manifold surface and lower intake manifold-to-cylinder head surface on lower intake manifold for warpage. Replace lower intake manifold if warpage exceeds .0059" (.150 mm).
5. Inspect exhaust manifold-to-cylinder head surface on exhaust manifold for warpage. Replace exhaust manifold if warpage exceeds .0197" (.500 mm).
6. Inspect cylinder block deck surface for warpage. Replace cylinder block if deck surface warpage exceeds specification. See «CYLINDER BLOCK»(ref-3005-S11537167302000041700000) table under ENGINE SPECIFICATIONS.
7. Inspect camshaft and components. See «CAMSHAFT»(ref-3005-S32568546162000041700000) . Measure valve lifter diameter and bore diameter. Ensure oil clearance is within specification. Replace components if not within specification. See «VALVE LIFTERS»(ref-3005-S36422520092000041700000) table under ENGINE SPECIFICATIONS.

Scheme 2

Scheme 3

Scheme 4

1. If installing exhaust manifolds on cylinder head, install NEW gasket for exhaust manifold on cylinder head with White mark toward exhaust manifold. (Scheme 2) Install exhaust manifold using NEW nuts. Tighten exhaust manifold nuts to specification using several steps. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). Install heat insulator on exhaust manifold.
2. If installing fuel injectors on fuel rail, install NEW grommet on each fuel injector. Coat NEW "O" ring with gasoline and install on each fuel injector. Use twisting motion when installing fuel injector on fuel rail. Ensure spacers and NEW insulators are installed on lower intake manifold.
3. When installing fuel rails, install fuel rails with fuel injectors on lower intake manifold. Loosely install fuel rail-to-lower intake manifold nuts. Using NEW gaskets, install front fuel pipe and front fuel pipe-to-fuel rail union bolts on front of both fuel rails. Install front fuel pipe clamp bolt in clamp at center of front fuel pipe. Tighten front fuel pipe-to-fuel rail union bolts and front fuel pipe clamp bolt to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
4. Install clamp and fuel return pipe-to-fuel rail clamp bolt on rear of driver-side fuel rail. Tighten fuel return pipe-to-fuel rail clamp bolt to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
5. Ensure fuel injectors rotate smoothly. If fuel injectors fail to rotate smoothly, check for improper "O" ring installation. Ensure electrical connector on each fuel injector is facing toward outside of fuel rail.
6. Tighten fuel rail-to-intake manifold nuts to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). If fuel pulsation damper was removed, use NEW gaskets when installing fuel pulsation damper. Tighten fuel pulsation damper to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). CAUTION: Gasket for driver-side cylinder head is marked with 2UL, and gasket for passenger-side cylinder head is marked with 2UR. (Scheme 3) Install gaskets on proper sides, with marking in specified area.
7. Install NEW gasket for cylinder head on cylinder block so mark 2UL for driver-side cylinder head, and mark 2UR for passenger-side cylinder head is located at proper area on cylinder block. (Scheme 3) Ensure all holes in gasket align with holes in cylinder block.
8. Install cylinder head. Apply engine oil on cylinder head bolt threads and cylinder head bolt-to-cylinder head contact surfaces. Ensure washers are installed on cylinder head bolts. CAUTION: When installing cylinder head bolts, ensure washers on cylinder head bolts DO NOT fall into area "A" on cylinder head. see scheme 12 If washer falls into area "A" on cylinder head, washer may fall into oil pan.
9. Install and tighten cylinder head-to-cylinder block bolts to specification in sequence. see scheme 13 See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
10. Apply sealant to groove at center of camshaft housing plug where plug contacts cylinder head. Install camshaft housing plugs at front of each cylinder head. (Scheme 4)
11. Install camshafts using proper procedure. See «CAMSHAFT»(ref-3005-S32568546162000041700000). Check and adjust valve clearance. See «VALVE CLEARANCE»(ref-3005-S27204172722000041700000) under ADJUSTMENTS. Apply sealant on groove at center of semi-circular plug where it contacts cylinder head. Install semi-circular plugs at rear of each cylinder head. (Scheme 4)
12. Before installing valve cover, apply sealant at specified areas on cylinder head. see scheme 4 If spark plug tube gasket in valve cover requires replacement, bend gasket retaining tab(s) upward. Using hammer and proper size bushing driver, drive spark plug tube gasket from valve cover. DO NOT scratch valve cover sealing surface.
13. Using proper size bushing driver, tap spark plug tube gasket into valve cover until spark plug tube gasket is even with valve cover surface. Bend retaining tab(s) downward. Coat spark plug tube gasket sealing area with grease.
14. Using NEW gasket, install valve cover, seal washers and bolts. Install and tighten valve cover bolts to specification in several steps. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
15. Using NEW gaskets, install front and rear coolant by-pass joints. see scheme 11 Tighten nuts to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
16. Install NEW "O" ring, and apply sealant at groove on coolant inlet housing assembly. (Scheme 5) Coat "O" ring with soapy water solution. Install coolant inlet housing assembly. Install and tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). NOTE: Install gaskets for lower intake manifold with White areas facing upward. (Scheme 6) Ensure all holes in gaskets align with holes on cylinder heads.
17. Install gaskets for lower intake manifold with White areas facing upward, and all holes aligned with holes on cylinder heads. (Scheme 6) Install upper and lower intake manifold assembly. Install and tighten lower intake manifold-to-cylinder head bolts/nuts to specification using several steps. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). CAUTION: DO NOT reuse old retainer when installing fuel inlet hose on fuel filter. Always use a NEW retainer.
18. To install remaining components, reverse removal procedure using NEW gaskets and "O" rings. Tighten bolts/nuts to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
19. When installing fuel inlet hose on fuel filter, apply light coat of engine oil to tip of pipe on fuel filter to allow for ease of disconnect fitting and fuel inlet hose installation. Using NEW retainer, install fuel inlet hose on fuel filter until "click" sound is heard. DO NOT reuse old retainer. Pull on fuel inlet hose to ensure fuel inlet hose is properly locked on fuel filter.
20. Ensure proper procedure is followed when installing timing belt on camshaft sprockets. See «TIMING BELT»(ref-3005-S06637290162000041700000). Fill and bleed cooling system (if drained). See «COOLING SYSTEM BLEEDING»(ref-3005-S17682609922000041700000).

Scheme 5

Scheme 6

1. Inspect timing belt for damaged teeth, cracking or oil contamination. DO NOT twist or bend timing belt inside-out. If excessive wear or damage exists on face of timing belt, check for nicks on idler pulley and water pump. If excessive wear or damage exists only on one side of timing belt, check timing belt guide and alignment of all pulleys and sprockets. If excessive wear exists on teeth of timing belt, check timing belt covers for damage, and foreign material on sprockets. Replace timing belt if damaged.
2. Ensure idler pulleys rotate freely. Inspect idler pulleys for oil leakage at seal area on front of idler pulley. Replace damaged components.
3. Inspect timing belt tensioner for signs of oil leakage. Replace timing belt tensioner if oil leakage exists. NOTE: Timing belt tensioner may seep a small amount of oil on rod seal under normal conditions. If excessive amount of oil exists, replace timing belt tensioner.
4. Hold timing belt tensioner with rod facing upward, and press rod against solid surface. DO NOT hold timing belt tensioner with rod facing downward when checking timing belt tensioner. Replace timing belt tensioner if rod moves.
5. Measure timing belt tensioner rod protrusion from end of rod to edge of housing on timing belt tensioner. (Scheme 7) Replace timing belt tensioner if distance is not.413-.453" (10.50-11.50 mm).

Scheme 7

Scheme 8

Scheme 9

1. If installing crankshaft sprocket, align crankshaft sprocket with key in crankshaft. Using hammer and Seal/Sprocket Installer (SST 09223-46011), install crankshaft sprocket with flange toward cylinder block.
2. If installing No. 1 idler pulley, apply Loctite or equivalent to bolt threads. Install plate washer, No. 1 idler pulley and bolt. Tighten bolt to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). Ensure No. 1 idler pulley is clean and rotates smoothly.
3. If installing No. 2 idler pulley, install No. 2 idler pulley and bolt. Tighten bolt to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). Ensure No. 2 idler pulley is clean and rotates smoothly.
4. If installing camshaft sprockets, ensure camshaft sprockets are installed with flange in correct direction. see scheme 20 Align groove in camshaft sprocket with pin in camshaft and install sprocket. Install and tighten camshaft sprocket bolt to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). CAUTION: Ensure timing mark or installation mark on timing belt aligns with dot on crankshaft sprocket when installing timing belt.
5. Ensure all sprockets and pulleys are clean. Align timing mark or installation mark on timing belt with dot on crankshaft sprocket. see scheme 21 Install timing belt on crankshaft sprocket, No. 1 idler pulley and No. 2 idler pulley.
6. Install gasket on timing belt cover spacer. see scheme 20 Install timing belt cover spacer. Install timing belt guide with cupped side away from crankshaft sprocket and flat side toward timing belt.
7. Install No. 1 timing belt cover. Align groove of crankshaft pulley with key in crankshaft. Using hammer and Seal/Sprocket Installer (SST 09223-46011), tap crankshaft pulley onto crankshaft.
8. Install accessory drive belt tensioner. Tighten bolts/nuts to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). Install generator. Tighten generator mounting bolt to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
9. Ensure crankshaft pulley groove aligns with center of bolt on No. 2 idler pulley. see scheme 22
10. Using spanner wrench, slightly rotate driver-side camshaft sprocket so timing mark or installation mark on timing belt aligns with timing mark on camshaft sprocket. (Scheme 8) Install timing belt on driver-side camshaft sprocket. Rotate driver-side camshaft sprocket counterclockwise until tension exists on timing belt between crankshaft sprocket and driver-side camshaft sprocket.
11. Using spanner wrench, slightly rotate passenger-side camshaft sprocket so timing mark or installation mark on timing belt aligns with timing mark on camshaft sprocket. (Scheme 8) Install timing belt on passenger-side camshaft sprocket.
12. On a workbench, using a press, slowly apply pressure on rod of timing belt tensioner until rod is retracted and holes in rod and housing are aligned. (Scheme 9)
13. Install hexagon wrench through holes in housing and rod to hold rod in retracted position. (Scheme 9) Release press and install dust boot on timing belt tensioner. Install timing belt tensioner. Install and alternately tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). CAUTION: DO NOT rotate crankshaft counterclockwise when checking valve timing.
14. Remove hexagon wrench from timing belt tensioner. To check valve timing, use crankshaft pulley bolt to rotate crankshaft pulley clockwise viewed from front of engine 2 full revolutions from TDC to TDC so crankshaft pulley groove aligns with "0" mark on No. 1 (lower) timing belt cover.
15. With crankshaft pulley groove aligned with "0" mark on No. 1 (lower) timing belt cover, ensure timing marks on camshaft sprockets align with timing marks on timing belt rear plates, and timing marks or installation marks on timing belt are aligned with timing marks on timing belt rear plates. see scheme 21 If timing marks are not aligned, remove and reinstall timing belt.
16. Tighten crankshaft pulley bolt to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). To install remaining components, reverse removal procedure. Tighten bolts/nuts to specification. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(ref-3005-S17682609922000041700000).

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-3005-S20180062212000041700000) 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. (Scheme 12) See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
3. Replace camshaft and/or cylinder head if oil clearance is not within specification. See «CAMSHAFT»(ref-3005-S20180062212000041700000) table under ENGINE SPECIFICATIONS.
4. Check camshaft end play with camshaft bearing cap bolts tightened to specification. Replace camshaft and/or cylinder head if camshaft end play is not within specification. See «CAMSHAFT»(ref-3005-S20180062212000041700000) table under ENGINE SPECIFICATIONS.
5. Install both camshafts in cylinder head without camshaft sub-gear installed on exhaust camshaft. Install all camshaft bearing caps except front camshaft bearing cap. DO NOT install front camshaft bearing cap when checking gear backlash. Tighten camshaft bearing cap bolts to specification. Check gear backlash between camshaft gears.
6. Replace camshaft if gear backlash exceeds specification. See «CAMSHAFT»(ref-3005-S20180062212000041700000) table under ENGINE SPECIFICATIONS. Measure distance between ends of camshaft gear spring. Replace camshaft gear spring if distance is not.716-.740" (18.20-18.80 mm).

Scheme 10

1. When assembling exhaust camshaft, install camshaft gear spring and camshaft sub-gear on exhaust camshaft. Ensure pins on camshaft sub-gear engage with ends of camshaft gear spring. Install wave washer and snap ring on exhaust camshaft.
2. Mount hexagonal area of exhaust camshaft in soft-jaw vise. Using spanner wrench, rotate camshaft sub-gear clockwise until holes in main gear and camshaft sub-gear are aligned. see scheme 30 Loosely install service bolt. Align teeth on camshaft sub-gear with teeth on main gear. Tighten service bolt.
3. Apply sealant on groove at center of camshaft housing plug where it contacts cylinder head. Install camshaft housing plugs at front of each cylinder head. (Scheme 4) CAUTION: Ensure crankshaft is properly positioned before installing camshafts to prevent valves from contacting pistons.
4. Using crankshaft pulley bolt, rotate crankshaft clockwise, as viewed from front of engine, so crankshaft pulley groove aligns with center of bolt on No. 2 idler pulley. see scheme 22 This will prevent valves from contacting pistons. Apply grease to thrust surfaces and journals of camshafts.
5. On passenger-side camshaft applications, install intake and exhaust camshafts so timing marks (one dot) on main gear on camshaft is at approximately 10 degrees. see scheme 27 On driver-side camshaft applications, install intake and exhaust camshafts so timing marks (2 dots) on main gear on camshaft are aligned. see scheme 27
6. On all applications, apply sealant at designated areas on front camshaft bearing cap. (Scheme 10) DO NOT apply or allow sealant to enter grooves on front camshaft bearing cap.
7. Install front camshaft bearing cap on cylinder head. Install remaining camshaft bearing caps on cylinder head in numerical sequence with arrow on top of camshaft bearing cap pointing toward front of engine. see scheme 28 Install NEW oil seal on intake camshaft and front camshaft bearing cap. CAUTION: DO NOT apply engine oil to camshaft bearing cap bolt-to-camshaft bearing cap surface on camshaft bearing cap bolts for front camshaft bearing caps. Engine oil may be applied only to threads on these bolts.
8. On bolts for front camshaft bearing cap, coat bolt threads with engine oil. DO NOT apply engine oil to camshaft bearing cap bolt-to-camshaft bearing cap surface on these bolts. On bolts for all other camshaft bearing caps, coat camshaft bearing cap bolt-to-camshaft bearing cap surface and bolt threads with engine oil.
9. Install oil feed pipe and camshaft bearing caps bolts. Ensure proper length camshaft bolts are installed in proper areas. (Scheme 11) Tighten camshaft bearing cap bolts to specification in sequence using several steps. (Scheme 12) See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000). CAUTION: Ensure service bolt is removed from camshaft sub-gear on exhaust camshaft.
10. On all applications, remove service bolt from exhaust camshaft. Check and adjust valve clearance. See «VALVE CLEARANCE»(ref-3005-S27204172722000041700000) under ADJUSTMENTS.
11. Apply sealant to groove at center of semi-circular plug where it contacts cylinder head. Install semi-circular plugs at rear of each cylinder head. (Scheme 4)
12. Before installing valve cover, apply sealant to specified areas on cylinder head. see scheme 4 If spark plug tube gasket in valve cover requires replacement, bend gasket retaining tab(s) upward. Using hammer and proper size bushing driver, drive spark plug tube gasket from valve cover. DO NOT scratch valve cover sealing surface.
13. Using proper size bushing driver, tap spark plug tube gasket into valve cover until spark plug tube gasket is even with valve cover surface. Bend retaining tab(s) downward. Coat spark plug tube gasket sealing area with grease.
14. Using NEW gasket, install valve cover, seal washers and bolts. Install and tighten valve cover bolts to specification in several steps. See «TORQUE SPECIFICATIONS»(ref-3005-S05931701232000041700000).
15. Ensure proper procedure is followed when installing timing belt on camshaft sprockets. See «TIMING BELT»(ref-3005-S06637290162000041700000). Fill and bleed cooling system (if drained). See «COOLING SYSTEM BLEEDING»(ref-3005-S17682609922000041700000).

Scheme 11

Scheme 12

1. Inspect components for damage. Coat relief valve with engine oil and ensure relief valve slides freely in bore of oil pump body. Replace relief valve and/or oil pump body if relief valve fails to slide freely.
2. Install drive and driven rotors in oil pump body with mark facing upward. (Scheme 13)
3. 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-3005-S41292588672000041700000) table.
4. Using feeler gauge, measure rotor tip clearance between tip of drive rotor and tip of driven rotor. Tip of drive rotor is on outside of rotor, and tip of driven rotor is on inside of rotor. Replace rotor assembly if clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-3005-S41292588672000041700000) table.
5. Place straightedge across oil pump body, above both rotors. Using feeler gauge, measure rotor side clearance between straightedge and surface of each rotor. Replace rotor assembly or oil pump body if rotor side clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-3005-S41292588672000041700000) table.

OIL PUMP SPECIFICATIONS

Scheme 13

Apply air pressure to one of the coolant hose pipes on oil cooler. Ensure air flows through oil cooler. Replace oil cooler if restricted or damaged.