oil temp sensor check?

[svandamme]

does anyone know what values the Oil temp sensor should read out?

i'm trying to test mine , but not sure if it's my sending unit , or my vdo gauge that's not working

so i figured i'll put the sending unit in boiling water
that should be 60 degrees C
and then read out the sensor with an resistance meter

is there a chart for that?


alternatively , can i test the gauge by putting a potentio meter on it, and checking the values on the dial , vs the current on the wire??


so far my gauge stays at 0 when the engine is warm
but when i put current on the gauge, the needle does max out

[Peterfrans]

AFIK boiling water is 100 degrees C

[svandamme]

Riiight, swiss cheese for memory....

Peter, do you have one of those sending units laying around for little test?

putting one in boiling water, and see how it's reading out?

[Peterfrans]

I must have one somewhere, I will have a look tonight

[Early_S_Man]

svandamme,

I ran a test on a new early VDO sender in a pan of cooking oil on a hotplate ... using a thermocouple probe and Fluke 52 thermometer, and measured the resistance at 10°F intervals from 70°F to 300°F.

If you substitute a 1000 Ohm potentiometer for your sensor ... you could test your gauge by sweeping the range, and temporarily disconnecting the pot. to measure the resistance that produces readings at your gauge marked points.

The early gauge was never off by more than 4°F over the entire range ... compared to the Fluke 52 thermometer!

Temp - °F -- Sensor Ohms:
70 1148
75 1000
80 918
90 756
100 607
110 504
120 424
130 357
140 301
150 260
160 219
170 189
180 162
190 142
200 122
210 108
220 92.4
230 82.2
240 73.2
250 64.2
260 57.6
270 51.2
280 43.8
290 39.6
300 35.4

[svandamme]

brilliant !! thanks Warren

don't have a potentiometer handy , but i can easely check my sending unit with this chart