TROUBLESHOOTING
Note. To trouble shoot engine mechanical components, see ENGINE MECHANICAL in BASIC TROUBLE SHOOTING article in GENERAL INFORMATION.
Inspection
| WARNING | Eye protection is required during use of compressed air. Failure to follow these instructions may result in personal injury. |
| CAUTION | The cylinder head surface finish is measured in microns. For correct head gasket sealing, avoid any contact of finish with metallic objects. |
- Clean gasket material, dirt and foreign material from cylinder heads. Wash with a suitable soap and water solution and dry the cylinder head completely using compressed air.
- Using a straight edge and a feeler gauge, measure the cylinder head surface for warpage. (Схема №164) Verify the measurement is within specification. See «CYLINDER HEAD»(ref-161157-S18955198402004040200000) table under ENGINE SPECIFICATIONS. If measurement is not within specification, resurface cylinder head.
- Inspect camshaft lobes for pitting or damage in the active area. (Схема №165) Minor pitting is acceptable outside the active area.
- Using a micrometer, measure the diameter of the camshaft lobes at 90° intervals, to determine lobe lift. (Схема №166) Lobe lift equals the difference in the 2 readings. Verify the measurements are within specification. See «CAMSHAFT»(ref-161157-S28870780932004040200000) table under ENGINE SPECIFICATIONS. If the measurements are not within specification, install a new camshaft.
- Using a micrometer, measure the diameter of the camshaft bearing journals at 90° intervals, to determine if the journals are out-of-round. Measure the camshaft bearing journals at 2 different points to determine if the journals are tapered. (Схема №167) Verify the measurements are within specification. See «CAMSHAFT»(ref-161157-S28870780932004040200000) table under ENGINE SPECIFICATIONS. If the measurements are not within specification, install a new camshaft.
- Using a dial indicator, measure the camshaft end play by sliding the camshaft in both directions. (Схема №170) Note the maximum and minimum values on the dial indicator. End play equals the difference in the 2 readings. See «CAMSHAFT»(ref-161157-S28870780932004040200000) table under ENGINE SPECIFICATIONS. If the measurement is not within specification, install new components.
- Check the camshaft bearing journal clearance by: Install the camshaft, without lubrication, into the cylinder head. Position a plastigage strip, equal to the width of the bearing cap, on the bearing journal. (Схема №168) Tighten the camshaft bearing cap to specification. See «TORQUE SPECIFICATIONS»(ref-161157-S07430046262004032200000). Carefully remove the bearing caps, being careful not to disrupt the plastigage. Compare the width of plastigage with the plastigage scale. (Схема №169) The plastigage reading is the bearing clearance. See «CAMSHAFT»(ref-161157-S28870780932004040200000) table under ENGINE SPECIFICATIONS. If the measurements are not within specification, install a new camshaft.
- Using a micrometer measure the diameter of the valve stems. (Схема №171) Verify the measurements are within specification. See «VALVES & VALVE SPRINGS»(ref-161157-S24250624562004040200000) table under ENGINE SPECIFICATIONS. If the measurements are not within specification, install a new valve.
- Using a vernier caliper, measure the free length of each valve spring. (Схема №172) Verify the length is within specification. See «VALVES & VALVE SPRINGS»(ref-161157-S24250624562004040200000) table under ENGINE SPECIFICATIONS. If the measurements is not within specification, install a new valve spring.
