Hey this is my first post, I’ll try my best to make this as comprehensive as possible. I’m going to share my issues with the cooling in my Volvo S80 and share the solutions that helped me. If anyone also has this issue or any other solution I’m looking forward from hearing from you.

So I daily a 2004 Volvo S80 2.5T AWD with around 165,000 miles. The car was bought almost 5 years ago and worked on regularly.

Most recently I’ve had issues with a dash message reading “Coolant Low Stop Engine”. Of course I did and it was low so I topped it off and looked for a leak and didn’t see much. A few days later the same message. I checked again and saw a slight leak on a radiator hose going from the rad to the thermostat. I ordered the replacement hose and threw it on thinking nothing of it. Come to find out that hose had melted from the heat, but my temp gauge had shown no issues with heat. Turns out the thermostat was bad causing the engine to overheat and showed no signs in the gauge cluster. This excessive heat lead to many more problems like an exhaust leak under the driver side, leaking coolant, destroyed fitting on the radiator and excessive engine wear. The exhaust leak has also caused trouble idling, check engine codes and a bizarre response to throttle. So to put it briefly, if you have a coolant leak check the thermostat, a $30 part could destroy your engine.

The only solution I found to this was to buy a new thermostat housing (couldn’t find just the thermostat locally). This has stopped my heating issues but ill still need to replace the radiator, repair the exhaust and replace the hoses. A temporary fix would be to just remove the thermostat but this keeps the engine blow operating temperature most times. I hope this might help someone having an issue similar any suggestions, comments or concerns are always welcome. (Ill attach videos and pictures of the mentioned issues at a later date)