So I've been searching for the source for coolant leak .....

[francis_a]

For months, I've been looking for the source of the coolant leak. It's a slow leak and over time, I just lose coolant and the light comes on.

After an oil change, I decided to take off the engine cover and lo and behold, I found something broken.



Is that the cooling system bleeder screw? The head on that plastic hex bolt is cut off and I believe that's where the leak is coming from as I can see traces of coolant on the driver side engine block, right around the fuel rails.

Gonna call the shop if they have a replacement and better yet, a stronger one.

[SlickFix]

Yep, that's what it looks like to me.

[Outerfroggy1]

Pretty common leak.

Mine was leaking in the same spot and I took it to dealer under warrenty. The tech put a stainless metric bolt in there with a copper crush washer. Smart man.

[francis_a]

Thanks for the replies.

Going to find that stainless metric bolt. I hate leaks

[walky_talky20]

Here is the official Audi replacement (metal!):
http://www.ecstuning.com/Search/ES470119/ES470119/

However, there is a Vin split in 2004 (8E-4-170 000), forward of which this replacement is called for:
http://www.ecstuning.com/Search/WHT000316/ES472266/

This corresponds directly with a change to that upper water pipe, so the newer cars (mid 2004+) may not be directly able to switch to that metal bolt/crush washer linked above. They appear to use a plastic bolt with an o-ring seal. The older pipe has since been superseded to the newer one w/plastic bolt. So I'm really not sure on the compatibility here. Both the plastic and the metal bolt are the same M10x1.0 threads (according to ETKA - they actually look different to me in the photos), so as long as that washer has a surface to seal, you're golden.

[Outerfroggy1]

My car is a 2005 and I have the stainless bolt/washer method.