Hi all,

Just did a pressure test on my '03 with bated breath, and I came up with favorable results (I think), but I wanted to verify something.

When I started the engine at first with the gauge attached the pressure was pegged at 50+ psi, which I figured was natural due to the higher rpms at cold startup. But over the next 10 mins or so the pressure gradually dropped to 22 psi where it seemed to hold steady.

Simple question: is that normal? I know the RAVE threshold is 10 psi at idle, so I'm not real worried about 22 lbs, just wondering about the falling pressure.

 

That is perfectly normal, when the oil is cold it is thicker than when at temp, thicker oil means better oil psi, simple physics there.
Not knowing the oil you are using that hot idle number is good, could it be better? Sure. Does it need to be? I dont think so.
Did you also test the oil psi at 2000 rpm when cold and hot?
What are those numbers?

 

Ah, that makes sense. I'm using Rotella 15-40 and a bottle of MMO (to try to cure a tick that didn't get cured).

I didn't get a REAL accurate 2k reading on cold and hot, just opened the throttle under the hood to where I thought 2k would be. Both hot and cold were similar actually, I think cold was pushing 50 or so, hot about 40ish.

 

FYI... the oil pressure relief valve kicks in at 50 psi, so you will not get higher than that.
2000 rpm hot should give you about 50 psi.

 

Where is this pressure relief valve located?..how do I know if its working properly. With my newly installed gauge, I sometimes get a reading above 50psi.

 

Tito gauges are not accurate, dont worry about the 50+ reading.
The bypass valve is in the oil pump and is meant to bypass the oil filter if it becomes clogged.
Cheap oil filters can cause problems with this too.