I had one leak in a hose under the hood. The smell came up though the gearshift boot.

... If you have a leak the coolant system will not have enough pressure and the system will not be at maximum capacity. Sounds like a good reason to be over heating.

... You might try a small amount of radiator seal but sometimes it doesn’t work with high pressure radiator caps. 

... You might connect the inlet and outlet of the core together with a small piece of tubing to by-pass the core.

... I have successfully patched aluminum cores with J.B.Weld.

Have a good one and see you later… Don S..

It would be nice if our members would add their vehicle information to their signature (similar to mine) plus add their City and State .

A member in the same town might be willing to drop by and help you with a problem. Or drink all your beer! One took my wife!... J/K