I heard that since bubbles are poppin up in my radiator coolant overflow that my water seals are bad and exhaust is comin up and heating up the coolant. Other symptoms are temp stays at 1/2 and then will suddenly go up sometimes and i am forced to stop and let it cool off. Any way I can be totally sure its the seals and not some lil thing? i fill the rad up all the way, drive it around for 10min then coolant fills up the overflow and a mixture of bubbles and coolant comes out of the overflow. The rad is then down about 10oz of fluid.

any help would be great!
Luke
If its definitley the engine let me know of a good place to get a rebuildable S4 or 5 engine or a cheap lo mileage S5.
thanks

 

Sounds like it. You need to have the cooling system:
1. Pressure tested
2. Checked for combustion gases