Camshaft: Diagnosis Lexus GS II

Inspection

1. Inspect components for damage. Check camshaft journal diameter, lobe height and journal runout. Replace camshaft if not within specification. See «CAMSHAFT»(ref-49511-S11866978002001011500000) 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. see scheme 19
3. Place plastigage on camshaft journal. Install camshaft bearing caps and bolts. Alternately tighten camshaft bearing cap bolts until snug.
4. Install Plastigage on camshaft journal. Install remaining camshaft bearing caps. Ensure camshaft does not rotate. Tighten camshaft bearing cap bolts to specification in sequence using several steps. see scheme 20 See «TORQUE SPECIFICATIONS»(ref-49511-S27767008102001011500000).
5. Remove bolts and No. 1 camshaft bearing cap from each camshaft. Remove camshaft bearing cap bolts in sequence using several steps. see scheme 20
6. Measure width of Plastigage to check oil clearance. Replace camshaft and/or cylinder head if oil clearance is not within specification. See «CAMSHAFT»(ref-49511-S11866978002001011500000) under ENGINE SPECIFICATIONS.
7. Check camshaft end play with camshaft bearing cap bolts tightened to specification. See «TORQUE SPECIFICATIONS»(ref-49511-S27767008102001011500000). Replace camshaft and/or cylinder head if end play is not within specification. See «CAMSHAFT»(ref-49511-S11866978002001011500000) under ENGINE SPECIFICATIONS.

Scheme 21

Scheme 22

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 21)
2. Install No. 3 and 7 camshaft bearing caps. Ensure camshaft bearing caps are installed in correct positions. see scheme 19 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 camshaft bearing cap at bearing cap-to-cylinder head surface and install No. 1 bearing cap. Install all remaining camshaft bearing caps. CAUTION: Ensure sealant is applied on No. 1 camshaft bearing cap at bearing cap-to-cylinder head surface. Ensure camshaft bearing caps are installed in proper location. see scheme 19
5. Install and tighten all camshaft bearing cap bolts in sequence until snug. see scheme 20 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 09316-60010), push oil seal into No. 1 camshaft bearing cap 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. (Scheme 22) Retighten these camshaft bearing cap bolts evenly to specification using several steps. See «TORQUE SPECIFICATIONS»(ref-49511-S27767008102001011500000).
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. (Scheme 22) Retighten these 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. (Scheme 22) Retighten these camshaft bearing cap bolts evenly to specification using several steps.
10. Check and adjust valve clearance. See «VALVE CLEARANCE ADJUSTMENT»(ref-49511-S31620702532001011500000) under ADJUSTMENTS. Install No. 4 timing belt cover. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49511-S27767008102001011500000). Install camshaft sprockets and timing belt.
11. To install remaining components, reverse removal procedure. Tighten bolts/nuts to specification. See TORQUE SPECIFICATIONS. Before installing gaskets and valve covers, apply sealant at indicated 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. see scheme 5 Coat distributor "O" ring with engine oil.
13. 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.
14. Align reference mark on distributor gear with groove on distributor housing. see scheme 14 Install distributor so bolt on cylinder head aligns with center of distributor flange. Install distributor bolt. Adjust fluid levels, control cables and ignition timing.

HINT: The thermostat is numbered with the valve opening temperature.

Scheme 23

1. Immerse the thermostat in water and gradually heat the water.
2. Check the valve opening temperature. Valve opening temperature: 80-84° C (176-183° F) If the valve opening temperature is not as specified, replace the thermostat.
3. Check the valve lift. Valve lift: 8.5 mm (0.335 in) or more at 95° C (203° F) If the valve lift is not as specified, replace the thermostat.
4. Check that the valve spring is tight when the thermostat is fully closed. If not closed, replace the thermostat

Scheme 24

Scheme 25

1. Place thermostat in water inlet Install a new gasket to the thermostat. Align the jiggle valve of the thermostat with the protrusion of the water inlet.
2. Install water inlet Install the water inlet with the 2 nuts. Torque 8.8 N.m (90 kgf.cm, 78 in.lb)
3. Fill with engine coolant
4. Start engine and check for coolant leaks