Water leak only when heater used

[Caracal13]

 

Hello,

 

I have a 2017 Dodge Journey (2.4l) that loses water only when the heater is used. Last winter water had to be added every day or two to the coolant reservoir. Water was dripping from the firewall a little left of center (closer to the steering wheel). When spring came and the heater was no longer being used, the dripping from the firewall stopped and water no longer had to be added to the coolant reservoir. The inside of the vehicle did not get wet, it only dripped from the firewall. Sounds like a heater core, but why would the dripping stop after the heater was no longer being used? Is there a bypass valve that diverts the coolant when the heater is not being used?

 

Thanks,

Caracal

[5rebel9]

Do you mean the drip is coming on the engine compartment side of the firewall???

And NO there is not a diverter valve that shuts coolant off from the heater core.

More likely is a case of poor hose clamp sealing of rubber hose to heater core tube(s) at the engine side of the firewall.

[2late4u]

I hope you weren't just adding water, as that would lower the coolant ability causing you to overheat the engine and ruin it, better have the antifreeze checked to see where it is at.......could be a bad hose or as mentioned a bad connector clamp,,,,Better get it checked out and fixed before you ruin your engine

[Caracal13]

Yes, the dripping is/was on the engine compartment side of the firewall. The carpet did not get wet inside the vehicle. It was dripping at about the same rate as the a/c condenser during the summer.  

 

Why would it stop after the heater was no longer being used? The vehicle has not lost any coolant since the heater was last used in March 2025.

 

Are the clamps that hold the heater hoses to heater core nozzles a common problem with Voyagers? 

[5rebel9]

without expounding the principles of contraction/expansion and properties of dissimilar items.... YES there have been troubles with clamping forces of the type clamps used on the Dodge JOURNEY and from what you have most likely read in your researching of this problem and found with VOYAGERS.

 It's fairly easy (compared to other vehicles) to reach those heater hose clamps and check for proper positioning, there is a bulge on the end of the heater core pipes that the clamp may not be properly positioned on the rubber hose to make good seal. OR the spring type clamp has lost it's force of clamping power.

 And YES in my decades of auto ownership and as an auto tech, I have seen such leaks happen during COLD weather and not during other seasons.

Good luck in taking care of this small concern and as said by member 2late4u, get it checked out BEFORE it turns into a MAJOR problem.

Edited October 12, 2025 by 5rebel9

[Dean H]

I agree.

 

Stop analyzing and get it checked it out. While you still have a running engine.

Edited October 12, 2025 by Dean H

[Caracal13]

Okay. Thank you for your responses. It is not my vehicle, a friend called and asked if I would have a look. It seems odd to me that it only drips when the heater is in use. If coolant is continuously moving through the heater core then it is pressurized when the engine is running. Therefore, it should leak whether the heater is in use or not in use. That is why I asked if the Journey used a bypass mechanism when the heater was not in use.

 

I will check the clamps at the firewall.

[John/Horace]

There is a separate manifold on side of engine that has its own thermostat for the cabin heat. On the 2.4 most leaks are from one of the seals on this assembly. I don’t work for these guys, best jpeg pics.
 

https://www.rockauto.com/en/catalog/dodge,2017,journey,2.4l+l4,3434427,cooling+system,thermostat+housing+/+water+outlet,10337