Anybody know what the normal range of oil pressure is for our 3.8L V6? I want to install a REAL oil pressure gauge but I don't want to install a 100PSI gauge and find it normally runs 40PSI. Anybody have a real gauge and can tell me the cold and hot range?

I have searched the archives and don't see that it has been posted before.

Thanks in advance,

Steve

 

the rage is very wide. ALL DATA says 5psi minimum(engine hot) light comes on at 4, at 3000 rpm 30-80psi is good. so that 100 psi gage sounds right.

 

A very good question, and I wish I had the answer.
My 94XJ with the 4.0 has always run between 40-60 at startup, dependent on the outside tempature, the colder, the higher the pressure. Running Mobil1 10/30 from 1995 after the switch to synthetic, along with a Mobil1 filter, and oil changes about every 6K miles, my pressure has stayed a constant 40PSI, during intown driving and highway speeds as well. On a hot summer day after driving the highway for a couple hours then coming into town, and sitting at a light at idle, the pressure has dropped to as low as 20 PSI, but never below that. I would think that the 3.8 would run about the same pressures, but since Chrysler has not seen fit to give us a gauge in the JK, I just don't know. Seems to me that with a full pan of oil and a good filter, and maintaing oil changes, the oil pressure should not drop to the 4-5 PSI that I understand the switch is set to, for a low pressure indication. I would believe that running a pressure of say 5-10 PSI for an extended time could produce an ill effect on the engine.
Perhaps someone who has hooked up a gauge could chime in.

 

Hey guys, sorry about replying to a very old thread, but I just wanted to chime in for new guys here looking for this information as this thread died at one comment lol. On my manual gauge, I'm running 30-40 psi at cold idle and 60 driving. At full temp I idle at 16psi and 58-60 psi driving.

 

Hi Alexander,

I'm glad you replied to this thread. I'm planning to add an oil pressure gauge to the 3.8L engine in my 2010 JK Rubi. Can you please answer a few questions ...

1. Does your Jeep have a 3.8L engine?
2. If "yes", where did you install the oil pressure sensor for your gauge?
3. What diameter and thread does the hole have in the engine block?

I already have a digital Banks iDash gauge installed and just need to add a sensor and analog adapter. I heard that there are two ports on the driver side of the 3.8L block where an oil pressure sensor can be inserted. One is occupied by the factory low-pressure sensor that triggers the low-pressure indicator in the instrument cluster at 4 psi. I'd like to leave it in place so the "idiot" light still works. So I'm hoping that I heard correctly and that there is a second port where a second pressure sensor can be added. If so, I need to know if an adapter is needed for the Banks sensor which has a 1/8 diameter and NPT (National Pipe Thread) thread. Thanks.

 

I have a 2010 3.8 Rubi also. The stock 'idiot light' sensor is on the passenger side of the engine. The extra port is on the driver's side, toward the front of the block and just under the exhaust manifold, it has a hex key plug. It's a 3/8" NPT so you'll need to adapt down to your 1/8" NPT sender.