What is everyone's oil pressure at idle?

having some issues trying to decide if this is an indication of the problem. I've developed a cold start knock. Fresh oil and oil filter. "Royal Purple". After sits for 8 hours or so it rattle/knocks. Usually only 10 seconds or so but sometimes 3-5 minutes. Almost sounds like a staving for oil situation or a leaking cylinder, (spark plug or head gasket or head or block) HOPING NOT THE LATER! but oil is full amd fresh and while cold have about 35psi at 700 rpm but after it's warmed up it drops to about 15psi at idle. Driving, it keeps (10psi per 1000rpm)+10psi. Little lower than I'd like but still in safe zone. Not sure if I should be checking the oil system, or looking for a new motor. I want this thing dependable daily driver and road trip vehicle but it's taking a lot of time and money and still hasn't earned it yet. Lol

 

eh..

change the filter again with a good quality filter like wix. Some filters can collapse and cause a low oil pressure problem.

 

I would check it with a manual oil pressure gauge first.
These clusters are know for not being the most accurate.

 

That pressure definitely seems lower than it should be. My engine with 200k miles on it has 50-60psi cold at idle and about 30-35psi hot at idle
What oil filter did you use? Also what weight oil are you running? I agree with above that and I have seen issues with some filters causing cold start knocks due to the anti drainback valves.


I always use ACDelco or WIX filters on GM engines.

 

My truck runs 60 cold and 20 hot. arent these trucks known for some knock. m does at start up also but goes away as it warms. Been doing this since I got it. synthetic seamed to help a bit

 

A lot of the newer GM engines are known for "piston slap" on cold startups. It kinda sounds like a lighter knock. Once the engine warms up and the tolerances tighten then the noise stops. Engines with "piston slap" can run that way for a very long time and not have any issues.

 

Wierd I just got the notification that anyone had replied.

Anyway oil is Royal Purple 10/40
Filter is Royal Purple oil filter as well.

I'm thinking the knock/rattle noise was a fuel injectors sticking. Ran a can of seafoam through a tank of gas and after about 1/2 tank it quite knocking as well as went from 14/15mpg to 17mpg on the last tank. I don't know how to figure out which injector it was now that it seems to be working again so I will probably just replace them all.

What I've found on the oil pressure is I'm thinking it's a bad reading. Before I read the replys I was working on the temperature blend door actuator and before replacing it I tried to reset it by pulling the Rdo fuse and the oil pressure gauge came up. Now it's reading 40psi at idle cold and 30psi at idle after it's warmed up. And maintains 40 at 2200 rpm cruising speed. Makes me feel a little better but I think I'll get a cheap mechanical gauge just to test and if it shows better then I'll add some good aftermarket gauges some how. I don't want it to look like a race car or farm truck either one so I'll have to find something that looks factory.

Thanks for the help guys!

 

well i havent gotten back to this yet, still. but was wondering. My old 2000 f150 had an Easter egg in the digital odometer that if you did something. I believe it was hold the trip button while you started it then you got a digital read out of full system on the odometer. You could cycle through, speed, tach, temp, oil pressure etc and several others not in the cluster and get real time exact feedback. does any one know if these can do it too our how to access it?