06 coupe, sport tuned suspension, premium package, 6mt, 154k miles, nearly perfect interior... Already replaced rotors and pads, new tires, both front struts, and a control arm... Drives great, uses some oil, not too bad...

Problem is I am smelling coolant and getting foggy windows, from what I can find here, I will have to pay someone to remove my dashboard to replace the heater core if that is above both my skill level nor do I have the tools... I have bypass the heater core for now so I can continue to drive the car.

My question is whether or not there is a possibility of using some type of radiator stop leak to fix my heater core since I have it isolated and don't have to worry about gunking up my radiator or engine itself... Could I just run the stopleak through the radiator core using an external pump? then flush it out before reconnecting it to the engine to prevent the gunk from getting into the rest of the system... I'm afraid that 12 to 16 hundred dollars to replace the heater core properly is out of my budget at the moment....

Any ideas or suggestions would be greatly appreciated I love this car and plan on spending whatever it takes to get it fixed properly in the long run but I need to make it through the winter...

 

First thing is to find the leak, rent a pressure tester and see where the coolant is coming from. You can remove the cabin air filter and use a borescope to look through the air duct to look at the heater core.

It's very likely the leak is somewhere else but the vapor is making it's way in to the cabin, failing heater cores are EXTREMELY uncommon. The hose may have ruptured right at the bulkhead fitting though which would cause the coolant steam to get up into the dash area. Or it's coming from the engine bay at one of the failure-prone fittings like the bleed valve and then the vapor is being sucked through the cabin filter into the cabin.

If you scope it out and it is leaking from the heater core then yes you could definitely try some Bars Leak liquid aluminum. If it's the difference between selling the car or not then it's better to just toss in the stop leak Just make sure to follow the directions on the bottle, it probably says to only use half a bottle but I would just use a turkey baster and suck out some coolant from the radiator then put the ENTIRE bottle in. For the next few days you will need to drive around with the heater temp turned to max and the fan speed on max, this ensures that the heater core valve is FULLY opened so the stop leak gets completely up into it.