Temp gauge

[Moo2]

Hi all,

So I know there is a lot of info out there about this but hard to narrow down my issue.. hope some one can help?

My temp gauge was completely dead so I tightened the nut on the back and cleaned/sanded the pins on the back, it now has power but the reading is still not right, it only goes up max just over the blue marker.

[biffer]

The reading you get is about right if your engine is a 6-cyl. one.
For a 4-cyl. motor the needle should be vertical/ 12-o-clock.

[steve_k]

is you engine a 6 cylinder? aka m20?

if so check the brown temp sensor in the thermostat housing,

[Moo2]

6 cylinder m20 320i year 1985

[steve_k]

in that case test the brown temp sensor,

disconnect the plug & the gauge should read zero,

ground the sensor & the gauge should go into the red zone,

if it fails to do either of these then replace it.

[Moo2]

Stupid question - how do I ground the sensor?

[Brianmoooore]

Stupid question - how do I ground the sensor?

Remove the plug from the sensor and use a piece of wire to connect the single pin in the plug to a good body earth.
Have you considered the possibility that the gauge is telling the truth, and the engine isn't reaching full temperature?

[Moo2]

So I have 2 sensors which seem to be wrong from my research...any ideas?

I’m not sure why the brown plug is connected to the blue plug?

And I bought a temperature sensor which only had 1 pin!?