SirAudi

2005 A6 60,000 miles 3.2 liter Quattro. No leaks, but losing 3/16" of coolant level in reservoir in 6,000 miles. No head gasket symptoms, performance is perfect, no evidence of a problem. Obviously I am going to just watch it for a while, but was hoping someone had a similar situation. Could the coolant level fluctuate that much? Evaporation? Normal consumption? Haven't measured the amount of coolant lost as the reservoir isn't down to minimum yet, can't be much! Thank you in advance for any info on the subject, google searches didn't turn up much on tiny coolant issues. Thanks again.

NoVA_A6

I've had to only add a little in my 05 over the last few years but not enough to be concerned and I think I'm still using the same liter of coolant I bought several years ago it's that negligible

SirAudi

Thank you for the quick reply. I would not be surprised if I have the same situation.

raj99

Your coolant reservoir could have microfractures, which occur over time or the cap could have a leak... Both are common issues which are simple fixes.

KevinGary

Plus 1

SirAudi

Thank you for the replies. I bought l.5 liter bottle of Pentosin Permafrost SF. Napa told me it was the G-12 equivalent as my dealer doesn't sell coolant. I added 300ml/8oz to fill reservoir to max. I noticed when tightening the cap it clicked into a locked position. It wasn't in that locked position before I filled reservoir up. Hopefully that was my whole problem, tiny amounts of coolant escaping as steam?? I will post back results in a month in case someone else has this "problem ".

SnowZach

There's a pressure vent in the cap that will allow coolant to escape if it gets over pressure. It's probably not perfect and some steam will escape occasionally. Every VW and Audi I've ever owned (and really any other brand) would loose coolant very slowly like this. Nothing to be concerned about. It just seeps past seals and cracks here and there.

SirAudi

To close the loop on my post, my engine is burning/losing 1/16" of coolant in the reservoir level per 1000 miles. That probably only amounts to a cup of coolant per year. Very insignificant problem unless the quantity increases significantly overtime. Thank you again for those who responded to my post.

assortedpixels

I had a very small leak pressure tested the system and turned it into a very big leak. I also have a low mile 05, this happened in the mid to upper 60k range for me earlier this year. In my case I was smelling coolant occasionally and it ended up being the heater core that was leaking.

kelisko

Same story here but I was never concerned because it is quite negligible.