Engine Mechanical: Diagnosis Lexus IS I

TROUBLE SHOOTING

To trouble shoot mechanical engine components, see ENGINE MECHANICAL article under BASIC TROUBLESHOOTING in GENERAL INFORMATION.

Inspection

1. Using caliper, measure cylinder head bolt diameter 2.0 in. (50 mm) down from bottom of bolt head. Replace cylinder head bolts if diameter is less than .421 in. (10.70 mm).
2. Using a straightedge and feeler gauges, check for warpage at cylinder head surface, and intake and exhaust manifold sealing areas. Replace cylinder head if warpage exceeds specification. See «CYLINDER HEAD»(ref-159232-S11734303692003111900000) table under ENGINE SPECIFICATIONS.
3. Check warpage of intake manifold, air intake chamber and exhaust manifold. Replace component if warpage exceeds specification. See «WARPAGE SPECIFICATIONS»(ref-159232-S24507597372003111900000) table. WARPAGE SPECIFICATIONS Application In. (mm) Air Intake Chamber .0059 (.150) Exhaust Manifold .0200 (.508) Intake Manifold .0059 (.150)
4. Inspect cylinder block deck surface for warpage. Replace cylinder block if deck warpage exceeds specification. See «CYLINDER BLOCK»(ref-159232-S35156272552003111900000) table under ENGINE SPECIFICATIONS. Inspect camshaft and components. See «CAMSHAFT»(ref-159232-S01079190232003111900000) .

Inspect components for damage. Measure 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-159232-S34421256862003111900000) table under ENGINE SPECIFICATIONS.
2. To check camshaft oil clearance, install camshaft in cylinder head without lifters installed. Ensure camshaft bearing caps are installed in correct position.
3. Place Plastigage on camshaft journal. Install camshaft bearing caps and bolts. Alternately tighten camshaft bearing cap bolts to 15 ft. lbs. (20 N.m). see scheme 29 Ensure camshaft does not rotate.
4. Remove bolts and No. 1 camshaft bearing cap from each camshaft. Remove camshaft bearing cap bolts in sequence using several steps. see scheme 29
5. Measure width of Plastigage to check oil clearance. Replace camshaft and/or cylinder head if oil clearance is not within specification. See «CAMSHAFT»(ref-159232-S34421256862003111900000) table under ENGINE SPECIFICATIONS.
6. Check camshaft end play with camshaft bearing cap bolts tightened to specification. See «TORQUE SPECIFICATIONS»(ref-159232-S31757476362003111900000). Replace camshaft and/or cylinder head if end play is not within specification. See «CAMSHAFT»(ref-159232-S34421256862003111900000) table under ENGINE SPECIFICATIONS.

Scheme 13

Scheme 14

1. Install valve lifters and adjusting shims in original location (if removed). Apply engine oil to camshaft journals and thrust surfaces. Install camshaft in cylinder head with camshaft dowel pins properly positioned and specified lobes facing upward. (Scheme 13)
2. Install No. 3 and 7 camshaft bearing caps. Ensure camshaft bearing caps are installed in correct positions. (Scheme 14) Coat all camshaft bearing cap bolt threads and bolt-to-camshaft bearing cap surface with engine oil.
3. Install camshaft bearing cap bolts in No. 3 and 7 camshaft bearing caps. Alternately tighten No. 3 and 7 camshaft bearing cap bolts until snug.
4. Coat lip of NEW oil seal with grease and install on front edge of camshaft. Apply sealant on No. 1 and No. 3 camshaft bearing caps at bearing cap-to-cylinder head surface, and install No. 1 and No. 3 bearing cap. Install all remaining camshaft bearing caps.
5. Install and tighten all camshaft bearing cap bolts in sequence until snug. see scheme 29 NOTE: This is initial tightening of camshaft bearing cap bolts. Bolts must eventually be retightened using specified procedure after oil seal is installed.
6. Using Oil Seal Installer (SST 09316-60011), push in oil seals as far as possible. Using wrench on hexagonal area of camshaft, rotate camshafts until camshaft dowel pin is at 12 o'clock position.
7. Loosen camshaft bearing cap bolts on designated camshaft bearing caps until bolts can be turned by hand. Perform STEP 1 in illustration. (Scheme 14) Retighten camshaft bearing cap bolts evenly to specification using several steps. See «TORQUE SPECIFICATIONS»(ref-159232-S31757476362003111900000).
8. Rotate camshafts clockwise until camshaft dowel pin moves an additional 1/3 turn (120 degrees). Loosen camshaft bearing cap bolts on designated camshaft bearing caps until bolts can be turned by hand. Perform STEP 2 in illustration. (Scheme 14) Retighten camshaft bearing cap bolts evenly to specification using several steps.
9. Rotate camshafts clockwise until camshaft dowel pin moves an additional 1/3 turn (120 degrees). Loosen camshaft bearing cap bolts on designated camshaft bearing caps until bolts can be turned by hand. Perform STEP 3 in illustration. (Scheme 14) Retighten camshaft bearing cap bolts evenly to specification using several steps.
10. Check and adjust valve clearance. See «VALVE CLEARANCE ADJUSTMENT»(ref-159232-S06833234782003111900000) under ADJUSTMENTS. Install No. 4 timing belt cover. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-159232-S31757476362003111900000). Install camshaft sprockets and timing belt.
11. To install remaining components, reverse removal procedure. Tighten bolts and nuts to specification. See «TORQUE SPECIFICATIONS»(ref-159232-S31757476362003111900000). Before installing gaskets and valve covers, apply sealant to valve cover sealing areas on front of cylinder head. see scheme 4
12. Ensure air intake connector gasket is installed with protrusion in proper location.

1. Inspect components for damage. Coat relief valve with engine oil. Ensure relief valve slides freely in bore. Install drive and driven rotors in oil pump body with reference mark (triangle mark) toward oil pump cover.
2. Using feeler gauge, measure driven rotor-to-oil pump body clearance. Replace rotor assembly or oil pump assembly if clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-159232-S04964784362003111900000) table.
3. Measure clearance between tips of both rotors. Replace rotor assembly if clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-159232-S04964784362003111900000) table.
4. Place straightedge across oil pump body, above both rotors. Measure rotor end clearance between straightedge and surface of each rotor. Replace rotor assembly or oil pump assembly if clearance exceeds specification. See «OIL PUMP SPECIFICATIONS»(ref-159232-S04964784362003111900000) table.

OIL PUMP SPECIFICATIONS