Why is There Coolant Leaking into My Car?

I don’t know if you’ve ever had the opportunity to own a car that was old enough or cheap enough that you had trouble with it leaking into the passenger compartment, but I have. I’ve actually had a few different cars that would get your wet feet if you jumped in after a rain storm. If you find yourself in a position where you’re asking yourself, “Why is my car leaking antifreeze inside my vehicle?” you’ll find that there are quite a few seals and openings into the cabin of your vehicle. This makes finding out where the water is coming from can often be a difficult job.

You can try checking the seals on your doors, especially if you have free standing windows like some Subarus and sports cars have. Make sure the window is rolling up all the way and the seal is well seated in the jamb. You can also check sunroofs and even your windshield seal. Most leaks into the cabin come through your ventilation system. Most cars gather air at the base of the windshield under the back of the hood and draw it from there through the blower fan. Unfortunately this is also a place water likes to collect. Most vehicle ventilation systems have a drain to let the water out of the ventilation box while keeping the air flowing through the blower. Check to see if that drain is disconnected or clogged.

The last thing you can check is to see if it really is water, or if it is an antifreeze leak coming into your car. Antifreeze runs through your heater core which usually sits somewhere behind or under your dashboard, many times on the passenger side. Heater cores are relatively fragile and it’s not unusual for them to acquire small leaks over time. To check if you have an antifreeze leak and not water, dab some up with a white cloth. If it is green, smells sweet or has a slimy feel it’s probably antifreeze.

Some other possible indications you need to stop a leak in the heater core:

vapor coming from your vents
a haze or fog on the inside of your windshield
a sweet small Inside the car
low coolant light

Due to the location of the heater core, most of the time they are extremely difficult to replace, even though it is a relatively inexpensive part. Due to the difficulty of replacement, repair costs can be high because of the long labor times that are charged. Often times, heat cores can even be difficult for a home mechanic to replace as well due to the number of electrical components that need to be removed and wires that will be left to get forgotten or crossed upon re-installation.

The best solution for fixing a leaking heater core is to seal it from the inside out. This process does not require removal of any components, nor does it pose any risk to the rest of your cooling system. BlueDevil Pour-N-Go is the best sealing agent for stopping a leak in your heater core. When your car is cool, add BlueDevil Pour-N-Go directly to your radiator for best results. Next time you drive your car, Pour-N-Go will be circulated through your cooling system by your vehicles water pump. Once your car is warmed up, there will be a temperature differential at the leak point in your heater core. This temperature differential will activate the chemicals in Pour-N-Go causing a permanent chemical weld at the leak point. BlueDevil Pour-N-Go is suitable for heater cores made of all types of material.