Bad Radiator Cap? / Coolant Disappears

[BlakeMAX2019]

I encountered a coolant disappearing issue with my 2019 Expedition Max with 50,000 miles. I routinely check my fluids, and two weeks ago, I noticed the coolant reservoir was low and had to add about a quart of coolant. Today, I checked it again, and to my surprise, the reservoir was almost empty. I had to add at least half a gallon of coolant just to bring it up to the minimum line. There are no signs of coolant on the ground or in the oil. I did notice quite a bit of condensation in the coolant reservoir, please see attached picture, and I’m wondering if this is the culprit being a bad radiator cap? I’m honestly dumbfounded by this vehicle’s reliability—or lack thereof, I’ve had multiple issues.

 

[Soliyou]

There are some potential issues:
- several members here reported water pump failures.
- some hoses have tendency to leak. The crimps at the plastic connectors are made of very thin aluminum that splits.

Inspect carefully around the engine bay for crystallized reddish coolant residue.

 

[sjwhiteley]

I have condensation in my expansion tank, but no leakage or loss of fluid. It’s also impossible to take the cap off when cold. It needs to be a hot engine to allow the cap to come off without risking breaking it. Don’t know why. If you suspect the cap, just get on their cap.

 

[BlakeMAX2019]

There are some potential issues:
- several members here reported water pump failures.
- some hoses have tendency to leak. The crimps at the plastic connectors are made of very thin aluminum that splits.

Inspect carefully around the engine bay for crystallized reddish coolant residue.

Thanks, I did a brief scan and did not see anything but I’ll have to a more detailed one. Let’s say it was one of the issues you mentioned, would that account for 1/2 gallon of coolant loss in 2 weeks? There’s never any on the ground, Im curious where that much coolant went?

 

[BlakeMAX2019]

I have condensation in my expansion tank, but no leakage or loss of fluid. It’s also impossible to take the cap off when cold. It needs to be a hot engine to allow the cap to come off without risking breaking it. Don’t know why. If you suspect the cap, just get on their cap.

Thanks. I’m able to get the cap off fine when cold however it’s one of the hardest caps I’ve encountered. Even if it was the cap, would that account for 1/2 gallon of coolant loss in 2 weeks?

 

[GlennSullivan]

That sounds like a lot of fluid loss. I would get up underneath to check the underside of the water pump and check all of the coolant hoses and pipes, especially those going to the turbos. The worst possible scenario is a head gasket, have someone follow you down the road, put the engine under load / boost and have them check for white smoke out the tailpipe, that will indicate head gasket or head issue.

Start watching this at 1:24 to get some ideas. https://www.youtube.com/watch?v=gtAv_YgXtOo

 

[BigOleFordFan]

~2-3 qts of coolant going **** in 2-3 weeks is definitely NOT normal....you definitely have a leak somewhere, just perhaps not in the places you may think as the typical ones...

You could also have a bad thermostat and/or temp sensor, that is letting the engine run hot but not giving any indications on the dash or the control module....and a bad cap could easily allow that much coolant to boil off if the engine is running hot

Best bet is get it to a shop, put it up on a rack, & let it get up to normal temps, then look underneath VERY CLOSELY & CAREFULLY with a very bright LED light, as well checking for any codes stored in the ECM....

 

[BlakeMAX2019]

Found the leak not sure if it’s coming from one or two places, but this is the hose that has coolant dripping from it. The shot of underneath the vehicle is where the coolant is dripping to the ground. Not sure if that hose is leaking as well.

 

[BigOleFordFan]

Nice photo work there, glad you located it, but just to be sure, I would suggest checking all other connections/hoses in the cooling system

 

[BlakeMAX2019]

~2-3 qts of coolant going **** in 2-3 weeks is definitely NOT normal....you definitely have a leak somewhere, just perhaps not in the places you may think as the typical ones...

You could also have a bad thermostat and/or temp sensor, that is letting the engine run hot but not giving any indications on the dash or the control module....and a bad cap could easily allow that much coolant to boil off if the engine is running hot

Best bet is get it to a shop, put it up on a rack, & let it get up to normal temps, then look underneath VERY CLOSELY & CAREFULLY with a very bright LED light, as well checking for any codes stored in the ECM....

Thank you for the post. I went out this morning to inspect for leaks, just as look under the car I saw a drip on the ground. I got under it and traced it to the Y-shaped heater hoses to the firewall. They’re leaking quite a bit, I posted pics but it seems to be a very common issue. I guess I’m not shocked about cheap plastic parts but I don’t expect them to fail with 50kmi. Have a Toyota that’s almost 20 years old with 240kmi and I’ve never had to replace a hose or plastic part on the car. Guess they just don’t make them like they used to.