temp gauge not working....where to start

[328Marcos]

I pulled out a sensor with four pin connector under the intake, screwed in the head when removed coolant came out, took it to a shop and they told me that was not my sending unit to needle on gauge. told me to look for one with only one wire. is this right? where am i looking for this sending unit and once found how do i test needle and gauge? Thanks

[Lord Vader]

That is the temperature gauge sensor. Theirs also A sensor on the radiator by the expansion tank.

[328Marcos]

what should i be looking at for a needle not working on my temp gauge?
where should i look? i took a coolant sensor out of the head under the intake with a 4 pin connector. but i was told it was the wrong one.

[328Marcos]

sorry mr vader, i thought you replyed... WHAT is a temp sensor. (my bad)
so im looking for a temp sensor , where am i looking? i found the sensor on the radiator and one on the coolant fill tank. the one on the rad turned on the fans and the one on the fill can is for low coolant right?

[Lord Vader]

Your correct. Those are the fan and low coolant sensors. That's why the one on the head underneath is the temp sensor.

What's the year and model of the car? If you enter your serial number on RealOEM.com you can search for the part number. Or see if there is a part number on the sensor and type it in.

[328Marcos]

1998 328is

[328Marcos]

if i replace the sensor and it doesnt fix it, what would be the next thing to check?

[Lord Vader]

Is this the part here: Pelican Parts - Product Information: 13-62-1-703-993-M323

If it fails to correct the issue then it's possible it's an electrical issue. But for $13 a new sensor is worth a shot first really. Check the wiring though and make sure theirs no short or anything.

[328Marcos]

mr vader, so got the new temp gauge sensor in , the light on the red side works now when i turn on the car then goes out after a couple seconds. that is new, but the gauge still does not move.

[328Marcos]

where shall i venture next?

[328Marcos]

also forgot to mention i got in the dash to inspect the back of gauge and all looked good. im woundering if i should try thermostat? anything?

[Lord Vader]

When you removed the cluster was the connection secure? Try an Instrument Cluster Test at the link below. If the the gauge is working, the needle will move following the conclusion of the test. If the needle does not move then the problem is with the gauge/cluster itself.

instrument cluster test