Hi All.

Over the past few day my 2003 A4 has started to lose coolant (about 1/2 a reservoir tank a day). I've topped the reservoir off twice now. I don't see any leaks, drips or puddles.

A glance under the hood and I saw this (I'm not even sure what part I'm looking at there):



I also checked the oil and while the consistency was normal the sides of the dip stick had a reddish liquid on them.

Any ideas? Head gasket maybe?

Thanks for any help,
Mark

 

well when i had a problem with leaking was the j plug which is located right next to the thermostat house or the flange on the back in front of the fire wall

 

that is the bleeder screw for the coolant.

 

Thanks, I did some research and it looks like that screw cracking and leaking is a common problem. Is it possible, though, that I'm losing that much coolant out of it?

Thanks, I'll try to look down there tomorrow and see if I see any signs of a leak.

 

likely the coolant flange. slow leak usually at high pressure and burns off only leaving a residue, likely that you won't smell it except very slightly. gradually gets worse until you start loosing so much coolant you overheat.

Check straight down between the engine and firewall on the passenger side and look for the residue on the exhaust. Many threads and DIY for it. Not expensive parts, just tight spots and time consuming to peel off the layers to get to it.

As far as the bleeder screw in the picture it wouldn't hurt to remove it when cold and clean it up. Corrosion could be letting a little seep out over time and continue to build up.

Good luck!