1992 toyota corolla dlx blown head gasket

hi just wondering my friend thinks i have a blown head gasket, but car never gets hot, there no water in the oil or oil in the water, what i do have is always creamy brown gunk in my radiator overflow bottle the water never lessens in the radiator, and after driving it when you stop there is a lot of bubbling under the hood , my radiator has the the 50/50 mix of coolant and water, already bought that way, does anyone have any other suggestions.

Your transmission cooler tubes run through your radiator. You may need to replace the radiator.

Check your transmission fluid to see if it is milky. Disconnect the small hoses from the bottom of the radiator (plug the hoses with golf tees or something) and with the coolant drained from the radiator, apply pressure to one of the inlet nipples which were connected to the transmission cooler hoses and plug the other. See if they hold pressure.

Alternatively, plug the radiator hoses and replace the radiator cap. With the small hoses disconnected, apply pressure to the radiator core and see if air comes out of the nipples.

If your transmission cooler is leaking in the radiator core, you will have to replace the radiator and flush the transmission to get rid of any coolant.