Heater coil

My car is leaking antifreeze on the inside under the dash. Is this a heater coil issue?. It is also smoking from the dashboard!. Yikes!. How do I fix or replace it?

The “smoke” you are seeing is likely vapour from the hot coolant that’s leaking. This is something that needs fixing right away. If you are lucky it could be a loose hose, but most likely it is a leak in the heater core. Most good shops can fix this and although the core costs about $60 or so, some cars need to have the whole dash taken apart and that can get costly.

On my 1976 Granada, it was nearly 8 hours labor. So budget at least $500 or so and best go to a specialty cooling system shop.

Yes, you have described the symptoms of heater core leakage.
The “smoking” that you observe is the result of coolant being aerosolized and then vaporized by the actions of the HVAC system.

In addition to causing a mess on the insides of the glass and creating an unpleasant smell, this vaporized material is very dangerous for your lungs when it is inhaled. I know that from personal experience, as a result of winding up with some really nasty respiratory problems because I did not realize for a couple of weeks that my Taurus’s heater core was leaking.

How do you fix it?
Well, depending on the exact make, model, and model year of your mystery vehicle, the only solution is to remove & replace the heater core, with the complexity of the operation depending to a great extent on the type of vehicle.

Some pickup trucks make it possible to do the job from underneath the hood, while almost all passenger cars require removal of the dashboard. In other words, this is one of those classic cases of parts that cost…maybe…$80, and labor that can wind up costing…perhaps…$500 or more.

In the short- term, you can eliminate the health hazard and the leakage by cutting the hose that supplies coolant to the heater core, and routing it back into the coolant passages of the engine, but, if you live in a part of the country where temps are beginning to drop daily, this approach is not recommended for anything more than…perhaps…a few weeks.