Coolant leak at the back of engine. Anyone gone through this?

[cjonesgo]

I have a coolant leak at the back of my engine. I can't find my inspection mirror anywhere, so can't tell exactly where it is coming from. It is near where the rear coolant flange is (which I replaced last year) but does not seem to be coming from it. At least not on top.
I can see coolant collected on top of my transmission housing, but just can't identify where it is coming out. From what I can see it is possibly:

Bottom of coolant flange plumbing.

or

Head gasket (between head and block) I REALLY hope that it is not this!!! No moisture in my oil, or oil in coolant so that is a good sign.


I was hoping someone had gone through this, and had a suggestion on what it might be. It is not a fast leak, only have to top up coolant every couple weeks, but still smell it and would like to fix it before it gets worse and strands me.


Thanks!

[cjonesgo]

for further clarification:

leak is at the back of the engine right at the firewall up top somewhere. no view available without some sort of scope or mirror and I don't have either.

I am looking for likely suspects on what to check

[A4ringedONE8T]

Most likely the coolant flange or the coolant flange o-ring. The quick disconnect on the hose coming from the heater core is also o-ring sealed to the flange as well as the CTS, could be one or any combination of those parts.

[7speed]

depending on if it is actually your rear coolant flange, I would advised doing this mod first
http://www.audizine.com/forum/showth...19#post2877619 it will save you countless hours

[cjonesgo]

depending on if it is actually your rear coolant flange, I would advised doing this mod first
http://www.audizine.com/forum/showth...19#post2877619 it will save you countless hours

I have not really been following this mod, been to busy lately to worry about any mods for the moment. What are the advantages of this aside from simplification of the system. What does it affect? still be able to pass smog etc?

[A4ringedONE8T]

I have not really been following this mod, been to busy lately to worry about any mods for the moment. What are the advantages of this aside from simplification of the system. What does it affect? still be able to pass smog etc?

Not something you want to do being in Cali. It will cause your car to fail all actual emissions test yes, however readiness codes can be set to passed with the correct software

[7speed]

Not something you want to do being in Cali. It will cause your car to fail all actual emissions test yes, however readiness codes can be set to passed with the correct software

oh Cali ......

[Turbo1A4]

i had the same problem it was the o-ring in the flange

[cjonesgo]

I replaced the flange and o-ring a little over a year ago. I hope it is that, because it is a straight forward fix, but I sort of doubt I am that lucky.

What else is back there that could be leaking?

[dirtyserby]

i had the same problem it was the o-ring in the flange

for me it was the flange....the biggest Pain in the ass job I ever had to do.

if you have big hands, you will hate your life.

I have scars on my right hand because of that god-damn flange, so I will remember it forever.

[B8Buckeye]

i had the same problem. it was the coolant flange. i replaced the temp sensor while doing it.

the job was a piece of cake for me. all i did was watch shawn and his tech, adrian, burn their arms trying to get past all the hot stuff back there. LOL.

[tuned A4]

yup. had to replace mine. its deff the coolant flange or the coolant flange o-ring

[jon102034050]

seems pretty common, i had it as well