Hi, this is a 1990 g60. I was driving this morning and suddenly started to see water vapor smoke coming from under the hood. There was high pressure coolant coming out of a small cylinder with 4 wires on top right next to the battery facing the front grill, on the side of the radiator) I could hear a pssssssss sound as if high pressure was being released from there. Thanks for your help. ( sorry im not being able to attach a picture(