hello GRM, I have a 90' 325is. I have had my bimmer for a couple months now, when I first bought it it had a weird problem, it would run hot (creep up to the 3/4) but only when i was idling or running at very low RPMs. i thought it was the fan clutch but after about a week and then it just completely stopped. so i left it alone. but recently i decided to check on the coolant when the engine was completely cool. as i unscrewed the overflow tank cap it slowly hissed for about a minute. now the same problem came back as before... why was there pressure in the cooling system when it was completely cool? did this pressure somehow fix the problem i was having with the idle? ALSO the coolant fan switch wires are messed up and possibly not making any connection. but it was like this the entire time ive had the car.
thanks for your help guys.