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C9 Oil Pressure Update

Yahoo Message Number: 22601
Ref. my recent questions related to "low oil pressure" at cruising speed. I took my Inspire for its 1st oil change since purchase at 4,000 miles (have a 1,000 mile round trip planned next week and did not want to wait till we returned.
Service was done by R-Mechanic in Livermore. At pickup they confirmed oil pressure hot was 40psi and 60psi cold, and gage is good. But they expressed concerns as they had to to use 42 quarts to refill sump and found excess oil blow-by dripping under the coach. They recommended taking coach to Petersons, local Cat service in San Leandro to check blow by and oil use.
Peterson confirmed a blow by filter, catch tank with reverse drain to engine is available for C7s, but not C9s till June. They suggested symptoms sounded like needing dipstick re-calibration and sump capacity check.

Turns out that normal capacity is 36-38 quarts. They re-calibrated dipstick so that the original "fill" mark is now the new "full" mark and they removed 4 quarts from sump to meet new levels.
Thay produced a data sheet indicating nominal oil pressure is 47.9psi, ceiling at 87psi and floor 36.3 with low idle at 20psi and floor at 10.7.

On trip home my new oil pressure at 1500rpm is now 46-48psi cruising.
Now I am feeling a little more comfortable with a "nominal" pressure.
Do not know how many coachers out there have had similar experience, but Cat mechanic states not all sumps and dipsticks are equal and matched and a comman problem. FYI. There was no charge by Cat as being warrantee work. They suggested checking and reseting valve lash at 5,000 mile when they fit blow-by filter.
T. & P. D

2006 Inspire 51455