GS300 & SC300
NOTE:
Check and adjust valves with engine cold.
- Drain engine coolant. Remove intake air resonator. Disconnect accelerator from throttle body.
- Disconnect engine wire clamp from throttle body clamp bracket. Disconnect engine wire from throttle body bracket clamp. Disconnect accelerator pedal position sensor, throttle control motor and throttle position sensor connectors.
- Disconnect air assist hose form intake air connector. Disconnect PCV hose from intake air connector. Disconnect EVAP vacuum switching valve connector. Disconnect EVAP hose from EVAP vacuum switching valve. Disconnect vacuum hose from No. 1 vacuum pipe.
- Remove nuts holding throttle body bracket to cylinder head. Remove bolts and nuts holding intake air connector to air intake chamber. Remove 2 water bypass hoses from throttle body. Remove throttle body and intake air connector assembly.
- Remove bolts, oil filler cap and timing belt cover No. 3 (upper cover with gasket). Remove ignition coils and wires. Remove spark plugs. Disconnect engine wire from valve covers. Remove valve covers.
- Rotate crankshaft clockwise until piston No. 1 is at TDC of compression stroke. Ensure groove on crankshaft pulley aligns with "0" timing mark on timing belt cover. Timing marks on camshaft pulleys should align with timing marks on timing belt cover No. 4 (upper inner cover). See Fig 1. If timing marks do not align rotate crankshaft clockwise 360 degrees.
- Measure and record clearance of intake valves for cylinders No. 1, 2 and 4, and exhaust valves for cylinders No. 1, 3 and 5. See Fig 2. Rotate crankshaft 360 degrees. Measure and record clearance of intake valves for cylinders No. 3, 5 and 6, and exhaust valves for cylinders No. 2, 4 and 6.
- Compare measured clearance with specified clearance. See VALVE CLEARANCE SPECIFICATIONS TABLE (GS300 & SC300) . If clearance is within specification, go to step 12). If clearance is not within specification, rotate crankshaft until camshaft lobe of valve to be adjusted is facing upward, away from shim.VALVE CLEARANCE SPECIFICATIONS
Application In. (mm) Intake .006-.010 (.15-.25) Exhaust .010-.014 (.25-.36) - Using a screwdriver, rotate valve lifter until notch on lifter is at a 90-degree angle to camshaft (perpendicular), facing centerline of valve. Using Valve Lifter Press (SST 09248-05410), press valve lifter downward. See Fig 3 and Fig 4.
- On all except cylinder No. 1 intake valve, position Valve Lifter Stopper (SST 09248-05420) between camshaft and valve lifter to keep valve lifter held down. See Fig 3 and Fig 4. Remove valve lifter press. Using a small screwdriver and magnet, remove shim. Select a shim of appropriate thickness. See SELECTING SHIMS under VALVE CLEARANCE.
- On cylinder No. 1 intake valve, remove No. 2 and 3 camshaft bearing caps. With side marked No. 9 down, position Valve Lifter Stopper (SST 09248-05420) between camshaft and valve lifter to keep valve lifter held down. See Figure. Remove valve lifter press. Using a small screwdriver and magnet, remove shim. Select a shim of appropriate thickness. See SELECTING SHIMS under VALVE CLEARANCE.
- Place shim onto valve lifter with imprinted numbers facing down. Press downward on valve lifter using valve lifter press, and remove valve lifter stopper. Recheck valve clearance to ensure it is correct.
- To complete installation, reverse removal procedure. Remove old valve cover seal packing material. Install NEW Seal Packing (08826-00080) material. See Fig 5. Use NEW gaskets as necessary. Refill cooling system. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS .
Fig 1: Identifying Timing Marks On Camshaft Pulleys & Timing Belt Cover No. 4 (Upper Inner Cover - GS300 & SC300)