FloridaThomas

Hey guys,
Ran into an issue with my 2011 A4 this weekend. I started up the car Saturday, drove a few miles and get a low coolant light. Its the middle of summer in Florida so i don't suspect anything major. However the engine starts to get hot so i stop as soon as i can and fill up with water as that's all i had on me. I went ahead and then preceded to fill her up with the special PEAK 50/50 Audi coolant, it only took a little bit. Having said all this, every morning since I've lost coolant with no visible signs of a leak. This morning I made sure it was full before i went to my office (29 Miles away) and just checked and the coolant reservoir was more than half empty. I've had the water pump and thermostat replaced within the last year. Anyone have any ideas? Thanks in advance!

- Thomas

SMac770

Seems to be a sizeable leak if you're losing half the overflow tank in 30 miles.
The first thought that comes to mind if it's not visible anywhere is to try the UV test and the gas presence test.
https://dannysengineportal.com/engine-coolant-leaks/
See if either of those give you a signal of where to look. There's no liquid or stain on the undertray under the engine? You might also have someone rev it up in place and see if you have a smoky white exhaust.