1987 N/A GTU sweet swelling white smoke, i get that its a coolant leak. Its coming out the exhaust, but the exhaust did have a gaping hole in a cat, not sure if that has anything to do with it, havent started it since i fixed it. Also in the car the water temp guage dont work, but when driving for a while the warning buzzer comes on and stays on. After the car is warm it dosent smoke unless high revs are hit 7-8, and it dosent smoke as bad as it does on the start. Coolant level is still good and dosent appear to be loosing anything too fast. I believe that its a seal gasket between the housings, but im not sure because i saw no bubbles in the filler cap. What can i do to locate this problem?

 

you don't need to see Bubbles to have a coolant seal failure.
Compression test the engine and Pressure test the cooling system.That will tell you If your Coolant seals are toast...and we all know what that means.