Heater core

NurseGuy

Active Member
May 27, 2019
109
17
28
Sylvania GA
So I think I have a small leak at the heater core. I can smell a very odd smell almost like sweet/electrical/antifreeze (ish). It is most prominent when I turn the heater on and the engine is cool. There are no obvious puddles on the carport floor and the floorboard is not wet. The smell mentioned above can also be smelled in the engine compartment and is most noticeable on the drivers side. It makes no sense to me. The heat still works, there is no fogging of the windows, and no spray on the windshield. If i do have a slow leak, is it safe to drive as long as I monitor my temp? What could this be and is there a way to tell for sure whether it's the core or not?
 
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Am I on a block list? Lol. Folks used to respond to postings but now it's radio silence. Just kidding. Turns out the smell I mentioned in my original post above has subsided. Heat works fine. No leaks. Is there anything else that could cause this smell while the heater is going? Almost like maple syrup.
 
Safe to drive? Yes...monitoring temp and checking your coolant level frequently (also check under the car for puddles before getting underway. How old is your radiator cap? It may be offgassing more than usual, if old, causing you to notice.
 
Why guess? Test! Perform a pressure test of the cooling system and then you will know for sure. Perhaps this will also help you to find to source of the leak.

Most auto parts stores will rent the tester for free (or a modest fee).

Or take your ride to a professional and have them do the work.

IF the leak is around the intake and the coolant is leaking into the cylinders this will damage the cats.

I can also tell you from personal experience that replacing the heater core is a BIG job. For me it took 3 weekends. One to take it apart. One to repair the control box. And another to put everything back together.

If doing the job again I'm certain I could do it faster the next time.

One piece of advice I can give on removing the dash. Don't try to use just the forums as an information source. I used a Chilton's manual AND the Ford service manuals and needed every bit of the information in both. The Chilton's had much better pictures. The Ford had more "step by step" and specifications.

Another piece of advice. IF the heater core is leaking and you decide not to repair. Do NOT cut and plug the heater lines. Instead loop them to each other. Why? Because the design of the water pump requires the flow of coolant through the heater hoses.
 
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I just went through this, to gain access you will have to remove the seats, console, dash ..it will take awhile. In my case it was an evaporator core, while I was there I replaced the evap, heater core, fan and anything else I could find because I never wanted to do it again..You can do it, just take your time and when you get pissed go inside and watch TV .
 
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Why guess? Test! Perform a pressure test of the cooling system and then you will know for sure. Perhaps this will also help you to find to source of the leak.

Most auto parts stores will rent the tester for free (or a modest fee).

Or take your ride to a professional and have them do the work.

IF the leak is around the intake and the coolant is leaking into the cylinders this will damage the cats.

I can also tell you from personal experience that replacing the heater core is a BIG job. For me it took 3 weekends. One to take it apart. One to repair the control box. And another to put everything back together.

If doing the job again I'm certain I could do it faster the next time.

One piece of advice I can give on removing the dash. Don't try to use just the forums as an information source. I used a Chilton's manual AND the Ford service manuals and needed every bit of the information in both. The Chilton's had much better pictures. The Ford had more "step by step" and specifications.

Another piece of advice. IF the heater core is leaking and you decide not to repair. Do NOT cut and plug the heater lines. Instead loop them to each other. Why? Because the design of the water pump requires the flow of coolant through the heater hoses.
are you saying make a "U" and connect the heater hoses together creating a continuous loop effectively bypassing the heater core?