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for the cylinder being tested. 10. Observe the J 26999 and note the reading as the compression test is being performed. See Special Tools. A normal cylinder reading will be indicated if compression builds up 11. Record the compression reading for the cylinder just tested. 12. Disconnect the J 26999 from the EN-47603 and remove adapter from the glow plug hole. See Special Tools. 13. Repeat steps 8 through 13 for all remaining cylinders. All 8 cylinders must be tested to obtain valid test results. Record the readings. 14. The minimum compression in any one cylinder is 2069 kPa (300 psi). There should not be more than 345 kPa (50 psi) difference between a suspect cylinder and the average Normal-Compression builds up quickly and evenly to the specified compression for Piston Rings Leaking-Compression is low on the first stroke. Compression builds up Valves Leaking-Compression is low on the first stroke. Compression usually does not CYLINDER LEAKAGE TEST Tools Required J 35667-A Cylinder Head Leakdown Tester J-35667-8 Cylinder Head Leakdown Adapter. See Special Tools. Test
2008 Chevrolet Silverado 1500 2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 45: Testing Cylinder Leakage CAUTION: Refer to BATTERY DISCONNECT CAUTION IMPORTANT: A leakage test may be performed to measure cylinder/combustion chamber leakage. High cylinder leakage Worn, burnt, or stuck valves Broken valve springs
2008 Chevrolet Silverado 1500 2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
1. Disconnect the battery ground negative cable. 2. Remove the glow plugs. 3. Rotate the crankshaft to place the piston in the cylinder being tested at Top Dead Center (TDC) of the compression stroke. 4. Install J-35667-8 and J 35667-A . See Special Tools. 5. Apply shop air pressure to J 35667-A and adjust according to the manufacturers instructions. 6. Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for Air leakage sounds at the intake manifold tube, may indicate a worn, stuck or burnt Air leakage sounds at the exhaust system tailpipe may indicate a worn, burnt, or stuck Air leakage sounds from the crankcase, oil level indicator tube, or oil fill tube may Air bubbles in the cooling system may indicate a damaged cylinder head or gasket. 7. Perform the leakage test on the remaining cylinders and record the values. OIL CONSUMPTION DIAGNOSIS Incorrect valve lash Damaged valve train components Damaged piston Worn piston rings Worn or scored cylinder bore Damaged cylinder head gasket Cracked or damaged cylinder head Cracked or damaged engine block IMPORTANT: It may be necessary to hold the crankshaft balancer bolt to prevent the engine from rotating.
2008 Chevrolet Silverado 1500 2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
The accepted rate of oil consumption, not due to leaks, is the use of 0.946 liter (1 qt) or less Oil economy should not be tested until the vehicle has accumulated at least 8000 km (5000 mi) Checks Causes Preliminary The causes of excessive oil consumption may include the External oil leaks Refer to Oil Leak Diagnosis. Incorrect oil level or improper reading of the oil level With the vehicle on a level surface, run the engine for a Improper oil viscosity Refer to the vehicle owners manual and use the Continuous high speed driving and/or severe usage Crankcase ventilation system restrictions or Oil residue in the charge air cooler system is normal with Worn valve guides and/or valve stems Worn or improperly installed valve stem oil seals Piston rings broken, worn, not seated properly
2008 Chevrolet Silverado 1500 2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
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