Normal exhaust/catalyst temp?*Update* Oil pressure

[Geotrash]

Thanks wsteele! Those numbers do match what I'm getting so that's good. I just could have sworn it used to idle around 30 psi but then again I rarely look at the oil pressure gauge and the last time I noticed the pressure was higher was probably months ago so it wasn't as hot out. It does idle higher on cold start which it is supposed to and climbed with throttle response. So I think I'm ok. Thanks again everyone. So far I am enjoying this place. Lots of good people and info.

You could be looking at a downward trend of oil pressure over time, which is common on these engines and has multiple potential causes. The most common is the oil sender screen getting plugged up, with the remedy being to remove and replace the sender and screen beneath it. The second most common is an o-ring on the oil pump pickup tube that hardens over time and starts having trouble maintaining a tight seal. The solution is to drop the oil pan and replace the o-ring. Other causes that are less common include cam bearings, oil pressure relief vales getting weak, etc. My advice would be to keep an eye on it and if it drops below spec, start with the sender and screen. Can be done with the intake manifold in place but it's a PITA and you'll be laying on top of the engine for a while

 

[Brandon2489]

I'm going to replace the sending unit along with the screen just to do it and see where it takes me. I have done one on a friend's Tahoe bit his was due to no oil pressure at all. I did it with the intake manifold on. Was about a 15 minute job. Used a 3/8 wratchet with a snap on extension with a permanent swivel and a sending unit socket. Thanks for the suggestions and I will keep an eye on it. I may eventually do the pick up tube oring only if the "fill with 2 extra quarts of oil and see if pressure goes up" method shows it's a problem. Thanks again everyone.

 

[Brandon2489]

Just a little update. It occurred to me that the previous oil changes I have done I have used PP 5w30 with AcDelco PF48 oil filter. This time I used the same oil but could only find the AcDelco PF48E filter. I now know that this filter has a plastic core. I know at 2 months ago I had higher oil pressure numbers when I changed the oil before a trip to Florida and now with 3k miles on this oil change I'm having oil pressure issues. Is it possible for this plastic core to have somewhat collapsed resulting in a lower oil pressure. I know the oil pressure is read after it has gone through the filter. Has any one heard of any issues with the PF48E filters? I'm still waiting on the oil pressure sending unit and screen to arrive so I will try to find a PF48 filter or use a K&N/Wix filter. I will try to change just the oil filter first to see what happens so I can keep all other variables the same.

 

[CaptainAmerica1]

Mine does the same thing. Fresh filter 35hot idle and 50 driving around, when I’m due for an oil change, 20hot idle and 42ish driving around. I change my oil every 3000 religiously.

 

[Brandon2489]

Well I changed just the filter to a K&N HP-2011. My oil pressure numbers have returned to normal. I have roughly 3000 miles on the oil. The oil still has a brown color to it. I usually go 5000. I may start to do them at 3500 and use the K&N from this point forward. I will not be using the AcDelco PF48E anymore. This is the first time I have had a vehicle where the oil filter has caused a drop in oil pressure. Thanks for the help. I will keep you posted on anything else.