Impala V8-5.3L VIN C (2006)
4. Install J21867 (1) or equivalent to the J-21867-16.
5. Run the engine and measure the engine oil pressure while observing both gages. Operate the throttle as required to increase and decrease the
engine oil pressure.
^
With the engine running and the lower pressure gage (2) measuring below 448 kPa (65 psi), both gages should display the same pressure
reading. If the readings are not the same and the lower pressure gage (2) has a higher reading, the oil pressure relief valve is stuck in the open
position or the valve lifter oil manifold filter is plugged.
^
With the engine running and the lower pressure gage (2) measuring above 448 kPa (65 psi), the upper gage (1) should display no greater
than 448 kPa (65 psi). If the reading on the upper pressure gage (1) is greater than 448 kPa (65 psi), the oil pressure relief valve is stuck in
the closed position.
6. Repair as required.
