Rode in my friend's 2006 GMC Duramax pickup today. Oil pressure gauge shows 0-120. Start up pressure was 60. After warmed up, pressure at 60mph was 30 lbs, sometimes 25. No higher than 30psi with high rpm's taking off from a stop. Idle pressure showed around 5psi. I didn't say anything but this seemed low to me. Anyone know if these are appropriate pressures on a Duramax? My intuition was that these pressures seem low and if it were mine, I'd confirm the gauge was accurate and if so find out why the pressure was low.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

My questions would be:

Is this a factory gauge?
How accurate is it?

I tend to fall back on the old Smokey Yunick philosophy of 10#/1000RPM being adequate.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Did some googling. Those pressures may not be out of line for a Duramax.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I do know earlier engines suffered fuel in the lub' oil....that would reduce overall oil pressure.
Oil Pressure - Minimum- Hot - at idle 14 psi..( 12 to 15psi.)..Oil Pressure - Minimum - 1800 RPM 42 psi.

Oil grade will make a slight difference like maybe a 10W something. The factory gauge is not accurate to rely on and oil pressure should be checked with a scanner.

Leaking injectors will slowly reduce oil pressure. Test oil quality with a Blackstone kit.Blackstone Labs



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__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Normal.

My 06 Duramax shows the same. I'm running Rotella t6.

__________________
-Justin

91 560 SEC AMG - other dogs dd
01 Honda S2000 - dogs dd
07 MB ML320 CDI - dd
16 Lexus IS250 - wifes dd

it's automatic.

Yeah...but what does the scanner read out say ?

This is lifted from Bulletin for '07 and up so may not apply. .................


"......If the oil pressure is 8 PSI or higher do not attempt engine or gauge repairs.

If oil pressure is below 8 PSI, continue with the SI diagnostics for low oil pressure, and make necessary repairs.

Note: The instrument panel gauge is buffered. The actual reading taken with the mechanical gauge may not correspond with what is seen on the instrument panel gauge. Rely on only the mechanical oil pressure gauge for this diagnosis......"




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__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Gm gauges for these trucks are not accurate... At least coolant.

Work on quite a few, and have seen coolant temp on scan tool at 190f , but it was at bit over 210 on dash gauge. One extreme example. However seen 10 f lots of time.

No idea on oil pressure gauge accuracy. It is pretty normal to see after hard run on interstate the OP gauge showing close to red bars. (5-10)

__________________
Dave

1985 190D 2.2 auto--gone
1975 240D 4-speed--storage
1985 500SEL--daily driver
1985 300TD--bad rust, soon to part out...
1982 300SD--waiting on engine from RD
1984 190E--storage
1996 Dodge 2500 Cummins--daily driver

GM trucks etc have had gauge cluster issues since about 2001 or so.my 05 the temp gauge rolled around to 100 and stayed my gas gauge was off 1/4 tank and the volt meter was 4 volts low.