CCsafedriver

I hope to solve this coolant leaking issue...I will definitely let you know what the outcome is! Thanks for your comments.

CCsafedriver

So, it was the aux pump and a hose. Replaced both and so far so good...knock on wood. Thanks for your suggestions.

meternerd

Here's a before and after...I wouldn't call it an easy job, but do-able for sure.

4Driver4

What's that green stuff? Wrong coolant!

Styles7

Hey guys. I'm new to the forums but not new to DIY and working on my own car. I got here via search for my 2004 a6 2.7t having a coolant leak. This is my first Audi so I'm still learning all the vocab and parts, bare with me.
About 19 months ago I can out to my car at work and all the coolant had leaked out after it was parked. I had it towed to a local acquaintance that runs a German only shop, hes a good dude and runs a nice shop. He replaced the usual... aux water pump, timing belt, all cam and valve cover seals and gaskets, water pump and thermostat.... Fast forward to today, I only drive 4 miles to work round trip. so over these past 19 months have not put very many miles on the car. During that time I have always noticed the coolant smell after getting in my garage and last week noticed a small puddle under the car when I left for work. I topped off the coolant and then a few days later while out at lunch in a drive thru I hear a faint plump sound and steam from the hood, about 2 blocks from my house, I limped home. Let the car cool down in the garage. Poured in some distilled water, in a few seconds it all ran out on the ground, left side (passenger).

I've now got it up on stands, bottom cover off, top engine cover off, pass side turbo intake lines off. Put a little water in and trying to see what is broken. It is clearly leaking down the side fo the oil pan and on the alternator like your pics above.

I need some help with a coolant hose/line diagram and the names of all the coolant hoses so I can look for specific parts and go but them.

Thanks for reading and the help!

CRuby

There is a coolant circuit schematic in this document that may be of some help, although it's just a schematic & not the actual visual layout.
http://www.ibiblio.org/tkan/audi/2.7...-SelfStudy.pdf

This link has illustrated parts layout, that could help a lot.
2004 Audi A6 Water cooling 2,7ltr.

Turbo inlet & exit lines are 18 & 19 & are located further aft of the alternator. If leak more toward front, check hoses 28, 32, & 54.

Styles7

Perfect! thank you so much. I had searched all day for that and I found a ton of diagrams for what seems like every other audi/vw engine out there.

Styles7

Also, I did end up finding the and I wish it was a hose.... the thermostat housing failed. I was lucky in that the chunk of housing didnt shred my timing belt and was just sitting there when I took the timing belt covers off. Still, super lame as my timing belt only has about 8k miles on it and I have no reason to take it off, till now.

jseklund

I was going to say - if this isn't the auxiliary water pump at the top, it is going to be the HOUSING for the thermostat, which requires timing belt removal to replace. It is a relatively common failure and I just had one go on a 2001 A6 my mom has - coolant would leak out like you are describing and when I got under, it was all over the oil pan and around the area near the alternator. I used an inspection cam to look under the intake and it was dry around the auxiliary pump. Once I took off the timing belt, it was clear the fluid was coming from the housing.

meternerd

Sure...RELAX....! You may just end up puking anti-freeze all over. I...in my vast wisdom....had a small anti-freeze leak only when driving. No leak while I was idling and looking under the car. So, I loosened the reservoir cap to "relieve the pressure" and sent my wifey off to town (15 miles). She called and said there was water all over under the car when she went to get back in. Guess what...it will overflow. Maybe this is just one in a million, though.....