Come & go leak at the heater core overflow tube

[BLK BRD 88]

Last week I fired up our 84 after it had sat for almost a month. While doing my walk-around I spotted a leak behind the front right wheel.
On closer inspection, it turned out to be the overflow tube on the heater core.
It dripped for a while, then stopped as the car sat idling.
A couple of days ago we packed up a gallon of mixed antifreeze/a funnel & headed on a 60 mile trip to see how it reacted. It didn't leak at startup, & never leaked again during the trip, nor when we shut it off in the driveway upon returning.
Is it possible that it has such a small leak that it seals itself when warm, or maybe the P.O. put some stop-leak in the radiator?
Is there any product to stop slow leaks that is recommended for these turbo engines?
Ron

[MikeFleming]

Does the car have AC? Was it run previously?

Was the stuff that "leaked" coolant or water?

It's very unlikely that a heater core leak will heal itself.


Is there any product to stop slow leaks that is recommended for these turbo engines? Not that you'd ever want to put inside a cooling system.

[BLK BRD 88]

Mike,
It has non-working AC. It was leaking coolant.
When we first started out a couple of puffs of steam came out of the vents, then no more signs of heater core failure.
I ran the heat, & the defroster, no fog on windshield??
Ron

[BLK BRD 88]

Update:
Last 60 mile run into town a couple of days ago; the antifreeze leak was nearly constant, the windshield fogged up when I turned the defroster on, & we smelled antifreeze in the car for nearly the entire trip.

Today:
The heater core is now isolated, and the intercooler has new neoprene hoses with new heavy duty metal clamps around them.
Ron