Oil pressure 36 ford

jacob smith

jacob smith

Senior Member
On start up the pressure reading in my car is perfect. Idle at about 15 running when hot around 25PSI. I checked with a oil pressure gauge. But some time after the car warms up the oriaganl gauge starts to push to the top at about 50. When I come to a idle drops back to around 20. Any thought of what might be wrong here. Do I need a new sending unit. Thanks for the help
 
I've noticed that the OP goes up and down to some degree (like the gas gauge) based on the voltage output of the generator. It is a resistive circuit that moves the needle depending on the current through the gauge, which will vary with the voltage.

However, if this behavior just started, then it's either the gauge or the sender. The sender is the easier one to change, I expect. You might take note of the generator output when the readings change and see if they match up.

Mine runs about 50 to 20 psi until the oil is thoroughly warm. (20/40 Rotella T3)

John
 
J Witt said:
It is a resistive circuit that moves the needle depending on the current through the gauge, which will vary with the voltage.
John
Click to expand...

Sorry, that is not correct, it is not a resistive circuit, it is a pulse circuit. There is a set of points in the sender that open and close. The rate at which this occurs determines the current (and there for heat) in the gauge circuit.

All of the early Ford gauges and senders work on a similar principle.
 

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Funny thing is I just installed a new genorator and it would make sense because when i let off the gas the amps and oil pressure go down. What should be down to solve the promblem or does that mean I need a new sending unit
 
Have your battery checked to make sure it is still good. Charge it up, then take it to one of the auto parts stores.
 
I agree with Terry, there is something not correct with the charging/battery system. I would start with the battery, as suggested. If the generator can not keep a good battery charged than need to look into that. But start with the battery, it's the most likely source of the problem.
 
I will check the battery but I am not having a issue charging. Amp meter reads around 10 when driving and a little above 0 when idling. I drove it to a show this morning with the lights on and it wa charging .

Lawson I have not polarized the genorator. How do I do that
 
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