oil pressure issue on cold engine?

[df_puffer]

Have a 2003 Yukon 6.0 with 220k miles. 5w30 mobile 5000 fresh oil. when I cold start in the morning I get 35psi idle and goes down to 30psi depending on rpms on a cold engine. when warmed up I get 35psi idle and pressure goes up with rpms...40psi at 1500rpm and 50psi at 2200rpm.

I have changed all the stepper motors about 5000mi ago and a leaking oil sending unit about 3000mi ago. don't have a mechanical pressure gauge yet to test/verify but dash gauge response seems to be correct maybe not 100% on value but close.

my question is that what could cause my pressure fall some when cold? I would think it would be highest when cold?

Thanks, Dwayne

 

[ezdaar]

Do this procedure at your own risk.
But it's never harmed a any engine that o have done this to.
But shit happens, so be warned.


Change the filter to a pf63, pour in half can of sea foam.
Drive it easy for 3 days. Then change filter and oil.
Use standard oil and anothe pf63 filter and the other half can of seafoam.
Drive it easy for a day or two then Get out of the freeway and get into it hard.
Do a couple WOT runs.
Then go change filter and oil to your fav syntec.

Oil pressure should be nice and steady and by now hitting some high pressures.


Mine was as low as 20 idle and wouldn't go over 40 during a wot run.
After that procedure, my cold idle 38' cruise 45, wot over 70.

 

[df_puffer]

Actually I am in my second Seafoam treatment...1000 mile oil changes with the last 50-100mi with 8oz seafoam. was going to do it 3 or 4 times. then switch to syntec.

Thanks

 

[ezdaar]

Add more seafoam. The instruction are very conservative to the amount used.
I've dumped full cans into engines in the past.

 

[afpj]

If seafoam don't help, consider the pickup tube Oring. I thought I read a post about that fairly recently.

Duh, it's a sticky already (i need new eyeballs): http://www.tahoeyukonforum.com/forum/showthread.php?t=67664

 

[TheAutumnWind]

Do this procedure at your own risk.
But it's never harmed a any engine that o have done this to.
But shit happens, so be warned.


Change the filter to a pf63, pour in half can of sea foam.
Drive it easy for 3 days. Then change filter and oil.
Use standard oil and anothe pf63 filter and the other half can of seafoam.
Drive it easy for a day or two then Get out of the freeway and get into it hard.
Do a couple WOT runs.
Then go change filter and oil to your fav syntec.

Oil pressure should be nice and steady and by now hitting some high pressures.


Mine was as low as 20 idle and wouldn't go over 40 during a wot run.
After that procedure, my cold idle 38' cruise 45, wot over 70.

Interesting. My oil pressure is usually 35-45 and maybe peaks at 50. I've never bought into the concept of this magic seafoam stuff that supposedly fixes everything, but is this something that I should consider trying?

Sent from my HTCONE using Tapatalk

 

[ezdaar]

There's nothing magical about it. It's simple a detergent that breaks down sludge. Opening up oil passages and allowing more oil to pass through.
As a by product your oil pressure goes up, well that's wrong way to say it..

Heres correct way.

It returns back to "what the engineers designed the oil pressure to be at". Aka normal.

 

[TheAutumnWind]

I guess my question should be worded more along the lines of: do my oil pressure numbers look ok? I have run transmission fluid with oil before since it is full of detergents (on a different vehicle), but I use Pennzoil platinum oils and that is supposed to be pretty detergent heavy also. I'll keep an eye on it for another oil change before I start messing with it.

Sent from my HTCONE using Tapatalk

 

[ezdaar]

Yess it's fine.

 

[TheAutumnWind]

Yeah mine often sits around 38 @ idle which sounds good compared to your numbers.