oil pressure question: 88 dodge ram w/ 318
#1
05-09-2010, 10:15 AM
oil pressure question: 88 dodge ram w/ 318
My oil pressure gauge reads about 1/8th of the given scale, which is just past the second "notch" on the "L" side. Ideally, I'd like to be able to test the gauge and the oil pressure sender separately (isolate the problem). So, my questions are:
1. Does anyone know what PSI the marks on the oil pressure gauge on the instrument cluster correspond to??
2. Is there any way to test the oil pressure gauge? I was thinking that shorting the sender connection should make it go to full scale?
3. Does anyone know the correspondence between the sender resistance and PSI?
4. Last but not least, are the gauges or senders prone to going bad?? Is this a normal reading for a 318 w/ 135k miles ???
And, yes, I am probably just going to buy an oil pressure testing kit...but I hate to buy things that will only get used once!!!
Thx, mike
PS - where can I find a socket deep enough to remove the oil pressure sender??
1. Does anyone know what PSI the marks on the oil pressure gauge on the instrument cluster correspond to??
2. Is there any way to test the oil pressure gauge? I was thinking that shorting the sender connection should make it go to full scale?
3. Does anyone know the correspondence between the sender resistance and PSI?
4. Last but not least, are the gauges or senders prone to going bad?? Is this a normal reading for a 318 w/ 135k miles ???
And, yes, I am probably just going to buy an oil pressure testing kit...but I hate to buy things that will only get used once!!!
Thx, mike
PS - where can I find a socket deep enough to remove the oil pressure sender??
Last edited by mjm1988; 05-09-2010 at 10:25 AM.
#2
05-09-2010, 10:48 AM
1. There is no correspondence between PSI and stock gauges. That is why they call them idiot gauges.
2. If it moves it is working even though the resistance values may have changed.
3. Again there is none as the resistance value changes with age.
4. Gauges and senders can go bad but I would not say they are prone to it. What actually happens is that over time the resistance in the sender and gauge starts to vary and therefore the gauge reading changes even though the pressure can remain the same. Gauges and senders are matched to each other by their resistance and a lot of after market senders will not give accurate readings with the gauge.
PS. I use a box wrench instead of a socket.
You can get a 0-100 PSI water gauge and fittings at the hardware store for a couple of bucks. This will give you a reading in PSI that corresponds to your trucks idiot gauge reading.
2. If it moves it is working even though the resistance values may have changed.
3. Again there is none as the resistance value changes with age.
4. Gauges and senders can go bad but I would not say they are prone to it. What actually happens is that over time the resistance in the sender and gauge starts to vary and therefore the gauge reading changes even though the pressure can remain the same. Gauges and senders are matched to each other by their resistance and a lot of after market senders will not give accurate readings with the gauge.
PS. I use a box wrench instead of a socket.
You can get a 0-100 PSI water gauge and fittings at the hardware store for a couple of bucks. This will give you a reading in PSI that corresponds to your trucks idiot gauge reading.
#3
05-09-2010, 11:56 AM
1. There is no correspondence between PSI and stock gauges. That is why they call them idiot gauges.
2. If it moves it is working even though the resistance values may have changed.
3. Again there is none as the resistance value changes with age.
4. Gauges and senders can go bad but I would not say they are prone to it. What actually happens is that over time the resistance in the sender and gauge starts to vary and therefore the gauge reading changes even though the pressure can remain the same. Gauges and senders are matched to each other by their resistance and a lot of after market senders will not give accurate readings with the gauge.
PS. I use a box wrench instead of a socket.
You can get a 0-100 PSI water gauge and fittings at the hardware store for a couple of bucks. This will give you a reading in PSI that corresponds to your trucks idiot gauge reading.
2. If it moves it is working even though the resistance values may have changed.
3. Again there is none as the resistance value changes with age.
4. Gauges and senders can go bad but I would not say they are prone to it. What actually happens is that over time the resistance in the sender and gauge starts to vary and therefore the gauge reading changes even though the pressure can remain the same. Gauges and senders are matched to each other by their resistance and a lot of after market senders will not give accurate readings with the gauge.
PS. I use a box wrench instead of a socket.
You can get a 0-100 PSI water gauge and fittings at the hardware store for a couple of bucks. This will give you a reading in PSI that corresponds to your trucks idiot gauge reading.
#4
05-10-2010, 04:10 PM
1. There is no correspondence between PSI and stock gauges. That is why they call them idiot gauges.
2. If it moves it is working even though the resistance values may have changed.
3. Again there is none as the resistance value changes with age.
4. Gauges and senders can go bad but I would not say they are prone to it. What actually happens is that over time the resistance in the sender and gauge starts to vary and therefore the gauge reading changes even though the pressure can remain the same. Gauges and senders are matched to each other by their resistance and a lot of after market senders will not give accurate readings with the gauge.
PS. I use a box wrench instead of a socket.
You can get a 0-100 PSI water gauge and fittings at the hardware store for a couple of bucks. This will give you a reading in PSI that corresponds to your trucks idiot gauge reading.
2. If it moves it is working even though the resistance values may have changed.
3. Again there is none as the resistance value changes with age.
4. Gauges and senders can go bad but I would not say they are prone to it. What actually happens is that over time the resistance in the sender and gauge starts to vary and therefore the gauge reading changes even though the pressure can remain the same. Gauges and senders are matched to each other by their resistance and a lot of after market senders will not give accurate readings with the gauge.
PS. I use a box wrench instead of a socket.
You can get a 0-100 PSI water gauge and fittings at the hardware store for a couple of bucks. This will give you a reading in PSI that corresponds to your trucks idiot gauge reading.
http://www.allpar.com/history/mopar/electrical2.html
#5
05-17-2010, 04:00 PM
I got the oil pressure gauge in the mail this weekend and the oil pressure checked out beautifully - 60 PSI @ 2000 RPM!!! Couldn't help myself, I went ahead and spent $16 ordering a new sending unit to see if I can get my "idiot" gauge to give a better reading...I know, a fool and his $$.....