Hi I really could do with someones expert advice and guidance. I have a 9-5 2.2 tdi 04 reg vector it has the following problem; I have had the car now for 3 years and have never seen the glow plug light on the dashboard and the car has always been a bit of a pig in the cold weather to start. When car is hot starts a treat, when car has been standing overnight in this cold weather it can take a good 5-6 seconds to start followed by a large white cloud of smoke, car runs fine on the whole just a b***** to start in cold weather. When the car starts from hot or in normal temp weather no smoke or any other problem. I decided to disconnect the plug to the water temp sensor on the top of the engine and hey presto the glow plug light came on ! Next time I went to start the car from cold I decided to remove the plug from the sensor and the glow plug light came on and the car started within a heart beat. So this led me to shoot off and buy a replacement sensor, which I swiftly fitted and hey presto next the next morning NO glow plug light and its a pig to start again. I thought I may have got hold of a duff replacement, but I think it does work as it appears to also control the engine temp display on the dash board. So in summary, water temp sensor appears to tell glow plugs when to turn on and also controls the engine temp on dash board, when disconected glow plugs come on and work but temp sensor on dash does not. Can anyone shed some light on this for me ?