2005 GMC C2500 Low oil pressure on cluster display

  • 2005 GMC C2500
  • V8
  • 4WD
  • 60,000 MILES
I'm working on a 2005 GMC 2500HD with a 6 liter v8. I'm getting a Low oil pressure warning on the I/C display. I have checked the oil pressure with a manual gauge, and I'm getting 5 psi at idle. I have replace the oil pump, o-ring seal on pick up tube. I'm still getting the low oil pressure. I tried a new O/P sending unit, no change. Any ideas?
Do you
have the same problem?
Thursday, May 7th, 2009 AT 9:28 PM

1 Reply

Check these things, If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following conditions:
" Oil pump worn or dirty

" Refer to Oil Pump Cleaning and Inspection.

" Oil pump-to-engine block bolts loose

" Refer to Oil Pump, Screen and Crankshaft Oil Deflector Installation.

" Oil pump screen loose, plugged, or damaged

" Oil pump screen O-ring seal missing or damaged

" Malfunctioning oil pump pressure relief valve

" Excessive bearing clearance

" Cracked, porous, or restricted oil galleries

" Oil gallery plugs missing or incorrectly installed

" Refer to Engine Block Plug Installation.

" Broken valve lifters

" Repair as necessary.

If the oil pressure reading on the J 21867, or equivalent, is within specifications, inspect for the following conditions:
" Plugged or incorrect oil filter and/or malfunctioning oil bypass valve

" Malfunctioning oil pressure gage or sensor

here is the oil pressure spec, Oil Pressure - Minimum - Hot 6 psig at 1,000 engine RPM

18 psig at 2,000 engine RPM

24 psig at 4,000 engine RPM
if all this checks good you might have a problem in the guage itself in the IPC. Post back with any other questions.
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Friday, May 8th, 2009 AT 12:49 PM

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