Loosing coolant

[BB540C2]

Ok guys, I've searched the forum before posting, so excuse me if I missed a post about this. I have a 2000 Excursion 4x4 with a 7.3. A little back story, went to have the oil changed & found I had oil in coolant fairly obvious ruptured oil cooled. Had it repaired & flushed to clean to get as much oil out of the coolant system as possible. Refilled with a 50/50 mixture of antifreeze & water. Well in approximately 2,800 miles since the oil change, I had to refill the degas bottle with 1gal of water. It was empty. Then 2 weeks later refill it again, with another gallon of water.

It runs great, no water in the oil oil. No visible leaks on the ground. No wet carpet inside front or in the back. No smell of antifreeze under hood or inside. No steam or anything out the exhaust.

Where the heck is this coolant going?[emoji2959]

Thank you for any input.

Carl

Sent from my SM-G955U using Tapatalk

 

[13fist]

I found my mystery leak at the back of the driver side head. The weird fitting had rotted out where it connects to the tube that runs back across the firewall. It never left a puddle or a noticeable smell. replaced all that mess with hose and a couple breeze clamps.
Mine was a bit slower leak than yours, I found it by accident looking at something else while the engine was still hot & running. I guess it was evaporating off the exhaust manifold? had me stumped for months.
have you tried pressurizing the system?

 

[tomlin]

Mine had a real small leak on the bottom of the water pump at the weep hole plug. It would never leak hot. I finally found the stains it was leaving on the belt/damper/pulley/lower hose. It was never wet when I looked at it but at some point during cool down it would leak and dry up.