Normal oil pressure or am I just over reacting.

[swathdiver]

It had a crappy Delco e core on it when I bought the truck and I put the same on when I changed the oil. I heard rose e cores can be crappy sometimes and cause this issue. I hope oreilys still sells the good none e core filters still. If not I put a wix filter on it.

I think those old ones are long gone. The K&N with the nut on the end is better than even WIX, which is a great filter.

 

[mdmcinti]

I'm just doing my oil pan and pickup o-ring. Also, the mesh screen was about 1/3 clogged. Once I'm done I'll be able to tell you if there is any change in my oil pressure. Currently, mine doesn't drop below 40 psi, BUT when I had my cracked head the coolant slowly mixed with the oil and began to sludge it. Then, it would drop below 40 psi. Even if all I did was change the oil filter, the oil pressure was restored, but I usually did a full oil change. I've since fixed the head and the oil pressure remains above 40 psi.

Now that I'm doing my o-ring, it will be interesting if my oil pressure goes a little higher. The old ring was a little squashed, but still working. Of course, I also had a partially blocked oil screen. I'll know in a day or two. ( I work slowly. Rickafix would probably have this all together in 15 minutes... not me )

I have done it on a 2wd Silverado and it was not that bad. No one told me I had to drop the steering rack for the pan to come off. I have never done it on a 4wd truck like my Yukon is. I’m sure lowering the axle isn’t all that bad. Let me know what you find out. As for the coolant thing, I should look at my coolant level. For all I know I have a set of castech heads that were never replaced.

 

[TheAutumnWind]

Bah... the more I look into this the more I realize that I need to address my low hot idle oil pressure. I am seeing in the ~25 psi range. I don't notice any sudden fluctuations or anything, just that it seems low. Ill have to top off the oil to see if it gets any better.

I am thinking I might as well just replace the pump and be done with it rather than drop the pan (and front axle... darn AWD) for an O ring. m295 here we come...

BTW running full synthetic 5w30 with uhh stp s3980xl atm. I have run mobile 1's and fram ultra synthetic filters and various full synthetic oils with the same pressure.
@~200k miles now.

 

[mdmcinti]

Bah... the more I look into this the more I realize that I need to address my low hot idle oil pressure. I am seeing in the ~25 psi range. I don't notice any sudden fluctuations or anything, just that it seems low. Ill have to top off the oil to see if it gets any better.

I am thinking I might as well just replace the pump and be done with it rather than drop the pan (and front axle... darn AWD) for an O ring. m295 here we come...

BTW running full synthetic 5w30 with uhh stp s3980xl atm. I have run mobile 1's and fram ultra synthetic filters and various full synthetic oils with the same pressure.
@~200k miles now.

I would think it would be easier to drop the axle than pull the crank pulley. I think pulling the crank pulley we be more difficult and doing it that way would be more time consuming since you have to remove more things like the water pump to get the timing cover off. These pumps are pretty bulletproof. The only thing that would go bad on the pump is the oil pressure relief valve. There is a video about that on YouTube.

 

[HACK BLOCK]

found this under common specs and procedures in my manual

 

[avalonandl]

As long as your over 20 psi your fine. These engines have lower pressure pumps.

 

[TheAutumnWind]

As long as your over 20 psi your fine. These engines have lower pressure pumps.

Interesting. Even the LQ9?

Its not that I am concerned that its going to blow up tomorrow, more that @ ~200k miles and 15 years old I figure that I would rather do this before it becomes a real problem.

 

[SnowDrifter]

33@hot idle is fine. You want it north of 30. Disregard the GM specs.

You have the same issue I had. Mine would fluctuate a bit, though mine was also verified with a mechanical gauge. Hook it up on your end to see if it's electrical or mechanical.

What I found on tear down was that the oil pump had some cavitation wear on the pump/rotor as well as scoring where the relief valve started to stick. New oil pump was the fix for my particular issue.

 

[TheAutumnWind]

33@hot idle is fine. You want it north of 30. Disregard the GM specs.

You have the same issue I had. Mine would fluctuate a bit, though mine was also verified with a mechanical gauge. Hook it up on your end to see if it's electrical or mechanical.

What I found on tear down was that the oil pump had some cavitation wear on the pump/rotor as well as scoring where the relief valve started to stick. New oil pump was the fix for my particular issue.

Yeah I am in the mid to low 20's hot idle.

 

[tjoyce81]

This sounds like a tell tail sign of a weak oil pressure relief valve spring (not the one in the pump - it is the one in the pan). It is THEE most missed and overlooked problem when it comes to oil pressure issues on these engines. In time your pressure may go down to zero or close to it and the low oil pressure alarm will ding. When/if that happens - it won't be the end of the world, because it is kind of a false reading. A weak pressure relief valve simply will dump more oil into the pan and it won't reach the sensor. You must drop the pan when changing this - so it is prudent to change the pick up tube o-ring while you are at it..
It is #455. Part #12594579.. OR you can simply install a plug and never have to worry about oil pressure again. My Tahoe did all of the above - and I changed everything (pump, pressure sensor and filter screen, pickup tube o-ring) before I studied the oil system and discovered the relief valve in the pan...