bad headgasket or waterpump ?
hi i have a 2001 530i i just got this car about 2 months ago. it does not overheat but i do have to put coolant in the expansion tank also i have checked the tub going from the valve cover to the ccv and i does have a yellow like gel in it but i read that it could be from moistuer .i can let the car idle for 30 minutes and it will not over heat or any power loss so im kind of stumped . also no codes ??? thanks for any input going to order the ECS Cooling Maintenance Kit .