coolant temprature guage

[Fraz06]

I've Got a 89 520i and when i go into the car and turn on the ignition without starting the car the needle on the coolant temprature guage goes straight into the red and stays there for bout 15secs then goes back in2 the blue section of the guage to tell me the engine is cold, i then turn the ignition back off and wait 2mins or so and turn the ignition back on and same situation the needle goes in2 the red section of the guage and stays there for 15 secs and goes back into the blue section of the guage this is constantly happening without me starting the engine up, does any1 know what is wrong and how to fix this problem ?

Thanks guys

[E34-520iSE]

Hi! Didn't you post this question a couple of weeks ago? Well, lets see if we can fix it for you then. What position does the needle go to after you have been driving for, say, 10 minutes? Have you tried disconnecting the BROWN temperature sensor plug on the T-stat housing? By doing that you will track the fault down to a bad instrument cluster or a bad temp. sensor.

HTH,
Shaun M