Temp Gage going to RED instantly

[vtyagi]

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?

[bmwbmwfan]

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

[vtyagi]

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

[m5james]

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.

[thedweeb]

Originally Posted by vtyagi

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?

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

[vtyagi]

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?

[rogerkiu]

you must circulate the cooling system after refreshing the coolent.

[m5james]

Originally Posted by vtyagi

it goes to RED (without starting the engine).

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.

[diyanich]

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

[vtyagi]

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?