Oil Consumption Diagnosis; Oil Pressure Diagnosis And Testing - Chevrolet 5.7L Corvette 2004 Shop Manual

damaged cylinder head.
Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder
head gasket.
7. Perform the leakage test on the remaining cylinders and record the values.

OIL CONSUMPTION DIAGNOSIS

Oil Consumption Diagnosis
Checks
DEFINITION: Excessive oil consumption, not due to leaks, is the use of 0.95 liters (1.0 qt) or more of
engine oil within 2 414 kilometers (1,500 miles).
The causes of excessive oil consumption may include the following conditions:
Preliminary
External oil leaks
Refer to Oil Leak Diagnosis .
Incorrect oil level or improper reading of the oil level indicator
With the vehicle on a level surface, run the engine for a few minutes, allow adequate
drain down time of 2-3 minutes and check for the correct engine oil level.
Improper oil viscosity
Refer to the vehicle owners manual and use the recommended SAE grade and
viscosity for the prevailing temperatures.
Continuous high speed driving and/or severe usage
Crankcase ventilation system restrictions or malfunctioning components
Worn valve guides and/or valve stems
Worn or improperly installed valve stem oil seals
Piston rings broken, worn, not seated properly
Allow adequate time for the rings to seat.
Replace worn piston rings as necessary.
Piston and rings improperly installed or miss-fitted to the cylinder bore

OIL PRESSURE DIAGNOSIS AND TESTING

Tools Required
J 21867 Pressure Gage and Hose Assembly. See Special Tools and Equipment .
J 42907 Oil Pressure Testing Tool
Causes