79 oil level sensor
 

I've searched and can't find an answer.

I have a 79 rx7 with s513b 4port swapped into it. I have a gslse oil pan and have the original 79 oil level sensor installed. It's in the hole in the pan meant for the sub zero sensor. My sensor started leaking pretty badly, looks like it's cracked. I know the 79 sensor is different than all the other rx7s and Mazda doesn't sell them anymore. My question is can I use a oil level sensor from a newer rx7? I have a spot for it in the pan, but I'm not sure if it will work with my stock wiring and idiot light.

Unless someone can give me an idea as to another sensor from another vehicle that would work. I'm sure I'm not the only 79 owner that's run into this problem. Just wondering if there's a solution or if everyone just removes the sensor..

Thanks for the help

As long as it threads in i would think any low oil sensor would work, all it is is a ON/OFF switch essentially

Since the 79 oil level sensor is a conductive sensor and the 81+ rx7's all had float sensors, I wasn't sure they would be compatible. If I had a spare fb sensor, I would just try it, but I don't. I want to make sure It will work to turn my idiot light on/off before I spend $140 on a new sensor.

The FSM for the 1985 oil level sensor test says "When the float is on the upper side, the ohmmeter should not show any continuity, and when moved to the lower side, it should show continuity in the circuit."

The 1979 FSM oil level sensor test say "Check the resistance of the sensor with an ohmmeter. The specified resistance is 2 ~ 4 kilo ohms at 10 ~ 30 degrees C (50 ~ 86 degrees F)

This basically tells me the 1985 sensor is open/closed switch. The 1979 is a variable resistance and probably never goes to open (infinity).

You might try testing the 1979 sensor by measuring the ohms at ambient temp and then placing in a pan of water and bring it up to a boil measuring and recording the resistance at difference temps with a food thermometer.

I'm making a guess here, but my theory is that when the 1979 oil is low, the temp at the sensor is lower then with oil in the pan. You might be able at add a resistor inline with the 1985 senor with a value you measured at ambient temp.