LLY oil pressures

[ynot]

Hi guys. New to the board and to the Duramax, so here I go again (traded in 565hp custom Dodge gadget mobile). First and easiest question. My LLY oil pressure cold is 80psi+ at idle, even now. With 1000 miles on truck, hot at idle is 22psi, 1800rpm w/ trailer is 44psi, and falls more with every trip out. Water temp is constant 208. Trans temp from 160/ 175, depending on ambient. Is this at all normal? Thanks guys...T

[mark45678]

Tony by the OEM dash on my lly truck I have just over 28 PSI at idle and 60 Psi at engine speeds over 2100 rpm.... HOT I have just over 13,000 miles on it. I dont think the OEM dash is really accurate!

[letsgo]

because my gauges are metric I'll use needle location, when the truck was new the needle never droped below 3/4 to 7/8 high position hot or cold. light load or towing, or even after an oil change.

At 42000 miles the needle never drops below the 1/2 way point when idling hot or cold or just after an oil change.

As soon as the idle rpm is increased the needle immediatlly jumps up scale to 7/8 high position light loads or towing,

Pulling up to a stop at a traffic light the oil pressure drops to the 1/2 way point.

good luck

[billnourse]

Tony,

My 2002 is as follows:

Cold:80psi at idle
Hot: 40 to 45 at idle, 65 to 75 at 2,000rpm.

I test drove an LLY the other day and noticed that the pressures were considerably lower than mine. Just about what you posted, so I would guess for that engine those prssures are about normal. Don't know why they are lower.

Your temperatures are about the same that I see, except I have seen 200 deg. on the trans temp. while towing through the Rockie Mountains at 20,000 Lbs GVW.

Regards,

Bill

[mark45678]

Tony some time in late 2002 or early 2003 GM made A change in there oil pumps on the duramax! this was done to stop or quiet the "tick " that many of us have complained about ..... I honestly dont think a motor that only turns 3300 RPM need 80 PSI of oil pressure! 20 at idle and 50~60 at speeds above 2300 is normal ...the type of oil you use and condition plays into this a little! Many Race motors are useing 0-30 oil to make them whip up faster!

[ynot]

Thanks for the replies, guys. It wasn't so much the actual numbers (tho 80+ did seem high for the supposed tight tolerances of the Isuzu) as it was such a dramatic drop from cold to hot. Sounds like it's where it needs to be tho. I dumped the oil and threw in a couple gallons Rotella, leaving the filter, and gained about 12psi back at road speed. What oil do they use from the factory, and does anyone happen to know the Famuto Quick Drain drain plug number for the Duramax? Thanks again...T

[jbplock]

Originally posted by Tony L. Welch:
... does anyone happen to know the Fumoto Quick Drain drain plug number for the Duramax?Tony,

The Duramax drain plug size is 14mm/1.5 so it takes the Fumoto Valve (http://www.fumotovalve.com/) F106N (or F106 without the nipple).

You can purchase them from Greg at www.lubespecialist.com (http://www.lubespecialist.com)

smile.gif

[mark45678]

Tony I think they are factory filling with 10-30 but I cant say for sure.... Mine had lower oil pressure with the factory fill then with rotella.... I have been useing rotella in all my trucks since 93! I think my truck will get rotella syn this winter ,walmart has 5-40 rotella syn in stock now....

[Inspector]

Is the Shell Rotella "syn" a full synthetic or a blend?
Denny

[ynot]

Thanks for all the help ya'll. I'll order the plug this week, JB... Mark, 10-30 is rediculously thin for a summer diesel, but accounts for the low numbers. Preciate the info... Inspector, it's full synthetic (but still Rotella. Mobile, Northland, etc. are rated much higher. Shell has been known to incorporate re-cycled oil in their 15-40. It's real cheap and about EVERYWHERE tho). Anyone know if there gonna make the Duramaximizer or Dynomite pressure box for the LLY? Thanks again...T