I have had a similar problem for the past two months. My glow plug light will stay on after the car has started. It will stay on for as long as I have dared to keep running it. I have had to turn off and restart the car two to three times to get the light to cycle off. If I let the glow plugs fire for 40 seconds or longer before starting the car, the light does not come on after start-up. I live in Palm Springs so I am not looking foreward to sitting in my 170 degree farenheit car this summer for one minute everytime I start the car. It seems to me that the problem has something to do with the ignition, because if I rattle the key a bit in the ignition it seems help a little bit. I do have a sporadic vacuum leak in my shut off. Sometimes it takes a few seconds to shut off, sometimes shut off is instant. I'm guessing that it's a vacuum leak at the ignition, but possibly a connection problem at the ignition-glow plug relay. I've searched high and low through the diesel forum and have not found the same problem that I have. Diesel gods--Please, I need your widsdom.