Hi I have a 2005 a4 1.8 and recently noticed that my coolant was low. Turns out there was a leak coming from the spot in the images below. I had a friend take a look and he put the hose that is circled until I get the cap that was originally in that spot. Unfortunately, I don't know the name of the cap or part number that I need. Can anyone help?





Thanks for the help!

 

I believe that's a coolant bleed screw. Check this link:

Genuine® W0133-1932955 - Audi A4 2005 Coolant Bleed Screw

Did it look similar to that?

 

wtf why is there a hose on it...

 

And green coolant