Coolant disappearing and reappearing 2000 s80 2.9L

Jamjarbinks · Post by **Jamjarbinks** » 30 Aug 2025, 13:10

Hey, I recently had to do a buncha work on my s80 due to a rad leak causing a head gasket failure, and have mostly fixed it. However I'm currently running into an issue with my coolant. After driving for a bit I get a coolant low msg, and when I check the reservoir it appears empty. However when I open it all the coolant flows up into the reservoir, fully up to the max fill line.

Ive just yesterday replaced the reservoir cap to seemingly no help.

My only other idea of what it could be is an air bubble, or the coolant is somehow blocked from circulating fully causing the pump to just push more in. Ive had no issues with overheating however, and it holds steady at abt ~90c

JaydieselV70R · Post by **JaydieselV70R** » 31 Aug 2025, 18:50

Seems like your coolant needs to do more Burping of air out.