Hey guys, I searched the boards, but couldn't find anything specific on this subject. I was wondering if I would have to drain the coolant to replace the coolant flange. I assume I need to replace that at least.
From appearance, it looks like coolant is leaking out of where the coolant temp sensor actually goes in. I can see dryed up coolant underneath where it is at and the coolant has gotten all crusty around the sensor. Do I need to replace the whole flange, or is there some sort of gasket or something.

 

There is a rubber 0 ring that sits between the sensor and the flange. I would try replacing the 0 ring and/or sensor before doing anything else. Since your taking the sensor out to put in a new 0 ring, you might as well just replace the sensor too if your car is more than 5 years old. Its a common part to fail with these engines anyway.

 

When I took out the coolant temp sensor yesterday, there was no rubber ring.....thanks again onepoint8tee

 

Are you SURE? Sometimes they get stuck down in the flange. Take it out again and stick your finger down in there.

 

alright...I will try that later, when the car has cooled down a bit and let ya know what I find.

 

I have a leak coming from the fiange on my wifes 02 A4 1.8.Do you know what the cost is to replace the flange?

 

Ok, so I did find that ring you were talking about, and I reset it back on the CTS. It doesn't appear to be leaking out of that area any more, (and I stress appear) but I did find some crusted up g12 where the flange meets that black metal pipe (forgive my lack of the correct word). So I am going to try and tighten the bolts where the flange meets that metal pipe and also where it conects to the engine.
I was at the audi dealership today, and they sell the flange for 31.00 bucks. In case I need to get the flange, does anybody know of a better website to pick one up?

 

at the dealer its about a $600 job...i made that $600 mistake..$500 for labor...get outta here

 

Dang...more than 500 even. I was wondering if you need to drain all the coolant before you change the flange, or can you just raise the rear of the car and loose a small amount of g12?

 

I got a quote here in Ct. from 300 to 400 .That was over the phone who knows what they will whack you with once they have it apart.