usbhjr

Last fall I put stop leak in the coolant system because Vapors were coming out of the heat ducts.I added it twice.The vapor leak has stopped but I've noticed a significant drop in the amount of heat.Is that due to a failing heater core?I'm thinking of having a new one put in.Thanks for any input.

MT-2500

If it was leaking it is time for a new one.
Stop leak is only a band aid on the problem.
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

usbhjr

Thank you for your input.I still get enough heat,but Im sure it's a matter of time and winter is rapidly approaching.

MT-2500

And if the old green coolant is is bad for your health to breath the fumes off of it.
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

ericn1300

Stop leak products will inhibit leaks, but will also clog the other coolant passages in the engine. If you do have to replace the heater core bypass it first by it by disconnecting the hoses from the engine and run them together and flush the engine to remove as much of the stop leak as you can, and refill with fresh antifreeze. Lots of post here on how to change it out, less than $50 in parts but a long job. It took me a full six-pack