5.3L HIGH oil pressure

[udlooz]

The vehicle is a 2003 GMC Yukon with 203,***
So far I have tried (yellow) Pennzoil 5w30, Pennzoil HM 5/30 and Castrol GTX HM 5/30.
I have replaced stepper motors, replaced oil sending unit and PCV valve

I bought the Yukon with 165,*** and the oil pressure needle was pegged at 80, figured it was sending unit and drove it straight home 350 miles that day

Replaced sending unit which fixed pegged gauge then changed to pennzoil at same time (I think pennz cleaned my seals too good because I also developed a drip leak)

Now that I could see oil pressure, when started/idle it is at 40 psi or a bit higher, at partial throttle it runs up to 60+ psi and at WOT it pegs at 80

I figured pcv issue and replaced valve, but old and new valve both just are hollow with a pin sized hole for venting

Since my first oil change I have been running Pennzoil or Castrol high mileage oil to try to seal the drip. It is gradually getting worse.

Should I be worried over high oil pressure?

 

[OR VietVet]

That oil pressure is good.

 

[udlooz]

Is it? I have two other 5.3 motors in my 2006 Sierra and my 2008 Tahoe and they both seem to run around 40 and bump up to 60 or so with wide open throttle... That's why I was worried, because this one seems to run higher

 

[OR VietVet]

I have an 02 AV and it carries the same oil pressure as your rig I say is good. Same engine. You now have a new sender in the engine. Perhaps the other 2 could use an updated sender. I would love to have that same pressure in all 5.3's I might own.

 

[clandr1]

I wonder if some sludge or contaminants are partially blocking your pump pickup tube? You might try running some additive like seafoam about 2-300 miles before you change your oil and see if the issue persists.

If your oil pressure gauge is continuously pegged at 80, and you've replaced the sender, it might be blockage. If you are saying it is only 80 at WOT, and is 40-60 otherwise, than that sounds like normal operation. Are you in a cold climate? If so, the oil thickens due to the cold and this results in higher PSI than you'd see in the summer.

 

[OR VietVet]

Yea, he said after changing the sender that the 40-60-80 psi scenario started to show and I say is good. Seafoam is a great additive to clean out the other rigs with and see what happens after a fresh oil change and new filter.

I forgot to ask him where the oil leak is at? What area do you see it?

 

[ezdaar]

Thats awesome pressures! If its not leaking or burning oil. Leave it alone.

 

[udlooz]

The leak is heaviest around the filter and also ultimately dripping from drain plug and bellhousing

 

[OR VietVet]

There is the seal and gasket kit for the oil filter housing that the filter threads on to. get FELPRO at Rock Auto and change out and then clean completely and short drive and then reinspect for any other leaks. Sounds like coming from there and blowing back. Or you don't have the filter tight.

 

[foxtrot moon]

I run Amsoil 5w-30 on my 2001 with 197k miles. I've had the Tahoe for a year now, and the oil pressure always surprised me, but I'm cool with it. When I start it up it's close to 80, when warmed up it'll run around the 50ish range, and when driving about 60. As someone else stated, I just leave it alone and change the oil when needed.

If only it didn't have piston slap on start up...