Oil Pressuge Gauge - 95 YJ w/ beastly 2.5 - I4

[MrChubbyHubby]

Since I bought this thing, the Oil Pressure Gauge has not worked right. When I start the Jeep up, it takes about 3 seconds for the gauge to peg to the right above 80. The needle never moves until I shut it down.

Here are my questions:
Is the OP Sensor located on the left side of the motor right behind the alternator?
If so... is this a good place to start troubleshooting / replacing?
IF that is the OP sensor, I disconnected the harness to it and started the jeep up last night, and I got the same result as if it was connected.
hmmmmm????????????

Could something be connected wrong under the dash????

Any thoughts would be greatly appreciated. Thanks

 

[bryanjeep]

YEs, the sensor is on the passenger side behind the alternator. My piece of crap 4 cylider usually reads right around 80 psi. I have heard that many jeeps do that, I doubt it is acurate.

 

[derff96963]

One suggestion I could make would be to put a manual gauge on it. I did it on mine and I am very happy with the results. I replaced engines in my jeep and the gauge worked with the one engine just a week before. When I put the other engine in I had no pressure when you started it, it would go up to 0 but no higher. I replaced the sending unit on the engine with no change. I was worried the oil pump was bad. I got a manual gauge just to make sure before I pulled the old pump out. I started it up and it went right up to 50 psi. I was happy and it has worked ever since. You can get a gauge at autozone for about $15 I think.

 

[Tug-n-pull]

camber adjustment on XJ?

I have a question about air in the line of a manual oil gauge. Is ther a way to bleed this off and get a more accurate reading. I have pulled the line and let it pump oil through the line but after a bit of time it get more air. Is this normal and am I worried about nothing here. tug

 

[jay79cj7]

I am not certain about this, but the wire to your sending unit might have a short.

I don't know about the oil pressure sender, but I assume that it is like the temp or gas gauge in that its basically a variable resistor and the 12V that goes to the gauge is grounded through the sender. As the resistance changes, the current through the circuit changes and so does your gauge reading.

If you are getting needle movement when you power up, that means you have a complete circuit. The fact that the needle doesn't move after it shoots over to 80 means that the resistance isnt changing and just might mean you are bypassing your sending unit and going straight to ground. I guess it could also mean that your sending unit is bad, but the fact that you get the same result whether or not you have the harness plugged to the sending unit tells me that the unit is not to blame, at least not entirely.

To check, I would disconnect the wire to the sending unit from the back of the gauge and the sending unit to isolate the possible short and just run a long wire from the terminal straight to the sending unit and see what happens. Just a thought. I have been able to get all of my gauges working just due to simple stuff like this.

Of course, this is based entirely on my limited CJ knowledge and may be completely irrelevant for a YJ.

 

[avyoung]

Tug

My new manual gage does the same thing. When it is running the oil goes all the way up so I figured it was normal. When I installed it the directions did not say anything about bleading it so I would assume it is normal.