Firstly you havent given much info as in 318i ??? build year ??? and are you sure its the coolant temprature sensor :
#15 here
RealOEM.com * BMW E36 320i Cylinder Head Vanos
this is for a 320i so you can do your own search on the above if you have a different model/year etc.If you cant find it or thats not the sensor then get back to me
Remember the more info the better chance of help!
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