I have a 2004 AWD Volvo XC90 that I bought a few years ago and have put a ton of miles on as my college car- it has some issues but overall has been holding strong for me! Recently, there has been a coolant leak that will empty out my entire reservoir, expecially when the AC is running. Ive been diligent in keeping coolant in the reservoir, but just the other day the temperature gauge quit working too. Any ideas as to what might be wrong and how I could fix it? Thank you!

 

Your first step in finding a coolant leak - would be a visual inspection followed by a pressure test. You might find a pressure tester for loan or rent at your local auto parts store.

For the temp gauge not working - visually verify the temp sender is still plugged in. With a compatible scanner you can view live data from various sensors - and the temp sender is one of them,.