smell anti freeze when ac or heat is on is it heater core floor not wet any info greatly appreciated
99 F-150

 

Unfortunately it appears to be a small leak in the heater core; which will ultimately require replacement. The core case is essentially a small "tub" that is probably holding the leaking fluid. Until that replacement can be made I'd try a premium leak stopper like Barr's Leak. It may actually help you get over a couple months to a year of service; pending core replacement.

 

i wouldn't recommend using a stop leak of any kind. it plugs heater cores, radiator and any small passages coolant has to flow through to do its job. your best bet is to save you money in the long run, just replace the leaking parts now that way you don't have do do it in the future plus what ever the stop leak plugs up.