oil temp guage

[WBofTN]

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My oil temp gauge has not worked since i purchased the car. Alan sent me a new SW guage which I installed this weekend.
Guess what:[xx(] still will not work.
So I'm calling for your expertise.
Is it the sensor - whats the part number?? or ground - needle went to
0 when I turned the key???????
WB

'93 Unique 427/351W/4sp

[Mike Geddes]

OK...here's my experience with the SW oil temp gauge.
For the longest time....almost 3 years...I figured my gauge was belly up.( same as my ammeter.)
Then I happened to take a long distance run...2000 mile round trip.
Some of the driving was pretty aggressive.
WOW...the gauge actually worked.....moved up to 142 degrees.
I think it starts at 140 low reading on the scale.
I have never actually checked what the oil temp. is by any other means.
The car runs a pretty consistant 190 degree engine temp....so 140 for the oil seems OK to me.
Maybe you do not have a problem with your gauge.
Mike

Mike Geddes

[WBofTN]

Mike:
My car runs around 190 for the most part also.
I have been as high as 230 in heavy traffic with no movement (oil temp).
this was however w/ the old guage. The ride I took this weekend was
only 10 miles or so and the air temp was around 63 degrees. So maybe your
right. I wonder if I could put a heat gun to the oil pan near the sensor to check it??? I have an ohm meter, but I'm not smart enough to use it other than checking continuaty (sp).
WB

'93 Unique 427/351W/4sp

[Jim Harding]

WB,

My mechanical oil temp sensor is located low in my 8 qt aluminum pan and will only register anywhere near the water temp gauge (180) in warm weather and when standing still..... the smallest amount of air flow around the pan causes the reading to go down about 20 degrees.

From some old notes around here, I show the electrical resistance of the SW oil temp sensor to be:
At less than 140 degrees, around 1000 ohms.
At 200, around 476 ohms.
At 230, around 300 ohms,

Water temp sensor should be around 130 ohms at 190 degrees.

Just remove the wire from the sensor and place your ohm meter (automatic ranging) from the block to the screw terminal. Not polarity sensitive, so just hook up the leads. I don't know about the heat gun trick, but if you can remove the sensor and dip it in some hot water, this will give you a go/no go condition. A meat thermometer placed in the hot water will give you a better indication of accuracy, but allow for some wide tolerance in both the meat thermometer and the gauge.

Some problem areas for the electrical sensors.... do not use teflon tape to seal the threads, as this sometimes will not 'ground' the body of the sensor to the engine block/pan, and the result will be a zero reading.

- Jim -

Jim Harding
La Plata, Maryland

1982 #3004
http://www.capitalareacobraclub.com/albums/album26/1aLeftside.thumb.jpg

[Okiesnake]

I used Teflon tape, but I drilled a small screw into the housing and added a small sheet metal screw for grounding (see http://pages.sbcglobal.net/tdockstett/OTmpSnd.jpg )

[GeorgiaSnake]

My oil temp probe is in the remote filter. I get high temps in the 190 / 200 range. I have the oil cooler disconnected for the winter and see about the same temps. You need to get the oil hot to remove water and fuel contaminants. My gauge is mechanical.

Randy

Unique 289 FIA
Southern Automotive 396
Team III 16's
Brilliant Silver

[eliminator]

You can also check the voltage to the sending unit, I remember when I wired my car that there was voltage flow to the sensors, oil & water tempt, it wasn't 12 volts, something like 6 or 8 volts. I drove yesterday and it was about 65 degrees it never moved off 140. My sensor is in the top of the Canton Oil Pan.

Eliminator

[WBofTN]

Jim and Eliminator:
thanks for the info, I will play with the ohm meter soon. Or try the
hot water trick. The new gauge could be working - just didn't get it engine hot enough to register.
WB

'93 Unique 427/351W/4sp

[Tony Radford]

WB, I concur with most of the points above. When I purchased my car, the sensor was mounted in the dipstick hole in the Canton oil pan. It never worked. When I got my new engine, I had the sensor moved to the remote oil filter bracket and it works fine. My engine runs 190 degrees in normal traffic and runs a steady 230 when I'm running hard. I'm also running a remote oil cooler. I did replace my original gauge with a lower temp gauge (280 I think) for a more accurate reading. My gauges are SW.

427SC, Torch Red / white stripes
427 Windsor Stroker from Southern Automotive
Delicious example of Beauty + Power.