Oil Pressure

[Farley_shawz]

Preface: 06 Sierra, lq9, 165k

 

Currently showing 40psi at cold start and stays there until coolant reaches operating temp. Hot idle will usually sit around 32psi some times dip down to 25psi. Will not go over 65psi at WOT. It used to never be lower than 40psi at idle and would peg out to 80psi at WOT. I changed the oil pressure sending unit hoping that was it, no change. I have not hooked up a mechanical gauge to check it. 

 

Looking for some thoughts.

 

Is my gauge cluster just malfunctioning? Oil pump? Pickup tube o-ring? Engine trash? Let me know what you think.

 

I read once upon a time something about gm saying that the engine is only supposed to produce 10psi for every 1000 rpm. I don’t buy that. 

[damnthetorpedoes]

Probably not what you are looking for; but that sounds like really good oil pressure to me. Honestly anything above 15psi idle I wouldn't worry about at that age. 

[Black02Silverado]

That seems normal to me for the mileage.  I understand it was higher and that is what you are use to but like stated above as long as it is 15psi or higher at idle is fine.  Rule of thumb is 1K RPM for every psi of pressure so 10psi at 1,000 RPM is all that is needed to properly lube the system.

 

Just curious, any change to the use of a different oil and filter?

[Farley_shawz]

No change. Valvoline 5w30 full syn, k&n hp1007 filter. Only thing I’ve ran since I’ve owned it. 

[Grumpy Bear]

1 hour ago, Farley_shawz said:

No change. Valvoline 5w30 full syn, k&n hp1007 filter. Only thing I’ve ran since I’ve owned it. 

Common enough that Melling has a high volume oil pump for high mileage motors to 'restore' pressure. That said, yours isn't that low....yet.  

[Brian715]

Sounds great to me. I drove my 06 for almost a year that had 0 psi at idle and wouldn't hit 40 at WOT before the engine transplant.  If you opt for a high volume oil pump beware of possibly running the pan dry with the stock oil level. 

[SunShine01]

I don’t know what kinda oil pump GM is using these days. But I do remember those spring ones on the V6 231 engines many years ago. Lol [emoji23].

With that all said. You got good miles on your rigs. Your rings are well worn so you’re simply not going to get new car oil pressure.

As long as she’s not rapping and getting circulation, you’re fine.

I use 20/50 conventional Valvoline Racing Oil in all my stuff for the last 25 years if not more. Getting hard to find, but with my heat in south Florida I think it helps.

When it gets cold I use the same stuff but 10/40.

Synthetics made my 98 Tahoe rear mains leak. When I upgrade to the next truck I’ll go synthetic but not on this 2005 Z71 Tahoe I got. 140k and she’s good. Uses no oil. But I change it every 3-4K.


Sent from my iPhone using Tapatalk