2012 Ford Focus, 155K miles, it is leaking a decent amount of coolant when my partner drives it to work but doesn’t even leak a drop if I drive it to work. The mileage is the same but I don’t sit in traffic. Could the extra heat from sitting in traffic be opening up a pinhole sized leak in the coolant line?
Edit: Thanks to a tip from the comments when the heat is turned on it leaks. I should be able to bypass that line pretty easy.
Thanks Kolgeirr@sh.itjust.works
When coolant heats up, it can evaporate of there’s a way out. Do you have any residue on the inside of your hood?
If you’re experience a LOT of coolant loss it could be escaping into the engine through a falling head gasket. In this case you wouldn’t see any residue on the inside of your hood.
God speed.
Inside hood is clean. The coolant hoses though look and feel like they are near the end of their life. I’ve not located where the leak is occurring, no signs of fluid on the engine block. The puddle I saw was next to the inside of the front right tire, under the coolant tank. I checked and it’s leak free.
I added some stop leak to see if that solves it for now. Car only has to last another six months before we replace it and my teenager gets to deal with it.
If its head gasket I would expect the loss to be consistent. If you open the rocker cover cap / oil filling point and it looks like there is Mayo in there, then it could be a sign the head gasket is failing.
I’m afraid that your partner has a coolant addiction and you need to get them checked into rehab.
On a serious note, perhaps sitting in traffic is causing the temp to increase and causing a leak. This would make me think perhaps the radiator fan isn’t working properly?
Any chance your partner uses the heater and you don’t? Many cars have a heater core bypass valve that only allows coolant into the heater core when the heat is on in the cabin.
Thanks! I tried this, and it leaked. The issue is at the heater core. I’ll putting together a bypass to the line that is leaking now.
So you are breaking the heater in your car and removing the defroster a safety feature? Just replace the heater core…
Even with that design it would leak coolant. The bypass just prevents the flow of coolant but it should always be primed with coolant even when it isn’t flowing.
It’ll be primed but not pressurized. Some leaks, especially in older rubber hoses, only leak under pressure when the swelling of the hose opens the split.
I’ve only seen bypass valves that block off one of the two heater core hoses to prevent flow but not both. Same idea as a thermostat blocks only one side of your radiator to prevent flow. So even though coolant isn’t flowing, it is heating up and pressurizing. There may be vehicles out there with an unusual design that blocks both inlet and outlet hoses to the heater core. But this isnt one of them.
Not trying to argue, just trying to share some of my knowledge as a former Ford tech.
Not a car expert, just a guy that learns how to do something when it needs to be done…
I don’t know how relevant the “why” is… you’ve got a leak, and the easiest first step is to inspect to see if you can figure out where the leak is originating from. If you can figure it out, then fix that. If not, the next easiest might be to just replace the coolant lines. If it’s still leaking after that, it could be either the radiator or a gasket.
Good luck!
