Temp Gage going to RED instantly
 

Anyone know why the temp gauge would go to RED with the engine being cold and there is plenty of coolant in the tank. When I put the key in, turn it 1/2 turn, it goes to RED (without starting the engine).

2001 X5 4.4

FYI, I just replaced the radiator, pump and thermostat along with all hoses!

So it has to be a sensor?...or does it need to be bled?

For someone I know, it was a faulty cluster. He had resoldered the capacitors in the cluster. Not sure if this applies to you.

No, I haven't messed with the instrument cluster. I only worked on the cooling system.

Sounds like you obviously missed something, time to start double checking. The fact that it never did this before will likely rule out that you have a cluster issue and simply missed or swapped a connector.

The circuit to the temp sender has gone to earth which in effect loops out the sender...Check your conections:thumbup:

I had to remove 3 sensor connectors:
- one located on top of thermostat
- one located on top of water pump
- one located on lower radiator hose

I removed, cleaned and re-set each one of them. Still the same issue.

Anything else? Perhaps one of the wires is broken inside? Or, has the sensor gone bad?

you must circulate the cooling system after refreshing the coolent.

The temp needle it going instantly to hot w/o the car even running, so that's not his problem. He's got a wiring issue, somewhere, somehow. Maybe Weasel can assist him w/ a pin out of the cluster and which wires to trace like I had to when resolving an oil pressure light in my mom's 328ci. After figuring out the wire had shorted somewhere, I was forced to run a new wire from the oil pressure sensor harness to the back on the gauge cluster.

try disconnecting one by one all of those 3 you have cleaned..should it point to the faulty one? I guess it should ,but I am not sure.
good luck

I think I have two options:
a) Take it into the dealer for a scan to see which sensor is reporting a short. Then trace the wire.
b) Cut the sensor wires and re-make them from scratch.
c) Remove the 3 sensors and place them in one by one while keeping an eye on the temp gauge.

Anyone other thoughts?