Oil pressure gauge not working on cluster swap

[ratty]

Hey. I just did a cluster swap on my 88 4.0 from dummy lights to gauges. So far everything is working fine except the oil pressure gauge. With the truck off, the gauge is at 40. When I'm moving, the gauge just goes up from there. Any ideas? Thanks.

[Strokermjcomanche]

You changed the oil switch to a sensor correct ? Did you use teflon or equivalent? 

[ratty]

2 minutes ago, Strokermjcomanche said:

You changed the oil switch to a sensor correct ? Did you use teflon or equivalent? 

 

 I changed the switch to a sensor. I used plumbers tape too. 

 

[Strokermjcomanche]

16 minutes ago, ratty said:

 

 I changed the switch to a sensor. I used plumbers tape too. 

 

Take the plumbers tape off and thread the sensor in , the threads will seal without the use of tape . It may be making the sensor read wrong . 

[ratty]

 

1 hour ago, Strokermjcomanche said:

Take the plumbers tape off and thread the sensor in , the threads will seal without the use of tape . It may be making the sensor read wrong . 

 

Ok. I'll try that. Thanks. 

[ratty]

1 hour ago, Strokermjcomanche said:

Take the plumbers tape off and thread the sensor in , the threads will seal without the use of tape . It may be making the sensor read wrong . 

 

I tried it, but nothing changed. When the engine is turning over, the gauge goes to zero. 

 

So when it's off, it rests at 40, when I start it, it hits zero, and when I'm idling, its at 50. 

[Ωhm]

Key Off, Engine Off. Remove wire at sender and measure resistance to ground thru sender. Should range between 0 - 5 ohms.

[HOrnbrod]

What's the manufacturer and part number of the sender you are using?

[Swampy]

keeping an eye on this thread because because my cluster just reads flat out past 80 psi

[ratty]

2 hours ago, HOrnbrod said:

What's the manufacturer and part number of the sender you are using?

 

I'm using the Duralast PS133 

[ratty]

3 hours ago, Ωhm said:

Key Off, Engine Off. Remove wire at sender and measure resistance to ground thru sender. Should range between 0 - 5 ohms.

 

I don't have the means to do that unfortunately.. 

[Eagle]

Try the super basic gauge test. Ignition on, but you don't need to start the engine. Remove the wire from the sender and isolate it. The needle should go to 80 (or peg to the right). Then ground the wire to the head or to a bare spot on the chassis. The needle should go to zero (or peg to the left).

 

If it fails either or both of those tests, either you have a bad gauge or there's a problem with the wiring.

[ratty]

1 minute ago, Eagle said:

Try the super basic gauge test. Ignition on, but you don't need to start the engine. Remove the wire from the sender and isolate it. The needle should go to 80 (or peg to the right). Then ground the wire to the head or to a bare spot on the chassis. The needle should go to zero (or peg to the left).

 

If it fails either or both of those tests, either you have a bad gauge or there's a problem with the wiring.

 

Awesome. I'll try it in the morning. Thanks. 

[HOrnbrod]

20 minutes ago, ratty said:

 

I'm using the Duralast PS133 

 

That's for an idiot light.

 

EDIT: Disregard, that's the correct sender for the gauge.  Do what Eagle said.

[ratty]

7 minutes ago, HOrnbrod said:

 

That's for an idiot light.

 

I copied it from here: 

 

https://www.naxja.org/forum/showthread.php?t=921205 

 

What should I be using? 

[ratty]

17 hours ago, Eagle said:

Try the super basic gauge test. Ignition on, but you don't need to start the engine. Remove the wire from the sender and isolate it. The needle should go to 80 (or peg to the right). Then ground the wire to the head or to a bare spot on the chassis. The needle should go to zero (or peg to the left).

 

If it fails either or both of those tests, either you have a bad gauge or there's a problem with the wiring.

 

Ok. So when I isolated the wire it went to 80 and when I reconnected it, it went to zero. When I drive it, it stays at around 40-70 and when I park it and shut the engine off it remains at 40 still. 

[Eagle]

"... around 40 to 70" is a large range. With the engine at normal operating temperature, what does it read at idle? What does it read on the highway at 60 MPH in overdrive (around 2,000 RPM)? If you're sitting at idle, in neutral, and you blip the throttle -- does the oil pressure show a momentary jump, or does it sit still?

[ratty]

1 hour ago, Eagle said:

"... around 40 to 70" is a large range. With the engine at normal operating temperature, what does it read at idle? What does it read on the highway at 60 MPH in overdrive (around 2,000 RPM)? If you're sitting at idle, in neutral, and you blip the throttle -- does the oil pressure show a momentary jump, or does it sit still?

 

 

At idle it stays at 40 on the highway it's around 70. Although, right now, after regrounding the wire it was at zero, but when I just started my car to try what you said the needle jumped to 70 and moved a tiny bit when I hit the throttle. After I shut the engine off it stayed at 70.  

[Eagle]

What year vehicle did this cluster come out of?

 

There's a reason for asking. At one time I had a 1984 Cherokee Wagoneer, with full gauges. The small gauges in the '84 did not (by design) return to zero when the ignition was switched off. They stayed at whatever position they were in when you killed the power. The next time you turned on the ignition, all the gauges would return to zero until you started the engine and they then had data to report.

 

That had changed by 1988, but I don't know when the change occurred. I don't remember if the gauges in my '87 go to zero when the ignition is switched off, or not -- and it's not running at the moment, so I can't check it.

 

It's possible that you just have an old-style cluster. Maybe your engine just has good oil pressure.

[Swampy]

My oil pressure sender on my 2.5l reads about 40ish psi at idle and when you blip the throttle it moves to about 60psi but returns to normal when back at idle

[ratty]

1 hour ago, Eagle said:

What year vehicle did this cluster come out of?

 

There's a reason for asking. At one time I had a 1984 Cherokee Wagoneer, with full gauges. The small gauges in the '84 did not (by design) return to zero when the ignition was switched off. They stayed at whatever position they were in when you killed the power. The next time you turned on the ignition, all the gauges would return to zero until you started the engine and they then had data to report.

 

That had changed by 1988, but I don't know when the change occurred. I don't remember if the gauges in my '87 go to zero when the ignition is switched off, or not -- and it's not running at the moment, so I can't check it.

 

It's possible that you just have an old-style cluster. Maybe your engine just has good oil pressure.

 

Interesting. I'm not sure what year it was out of. I got it from a junk/part store. 

 

Thanks for your help. 

[Minuit]

99% certain that the gauges in my 91 also stay where they were when you shut the engine off.. Once you turn the key back on the oil pressure gauge goes back to 0.

 

edit: Yes, they "stick". The engine is definitely off in this pic:

 

Unless I'm misunderstanding things there's a decent chance your gauge is working correctly, ratty.

[ratty]

36 minutes ago, Minuit said:

99% certain that the gauges in my 91 also stay where they were when you shut the engine off.. Once you turn the key back on the oil pressure gauge goes back to 0.

 

edit: Yes, they "stick". The engine is definitely off in this pic:

 

Unless I'm misunderstanding things there's a decent chance your gauge is working correctly, ratty.

 

Well that's good news haha. I'm not used to that sort of thing happening. Thanks.