Hi All,

Hope I'm posting in the right place and someone with some more knowledge than I have can give me a clue as to what's going on with my car. Here's the situation: 2005 A4 1.8TMQ, 43k miles. There's a good amount of coolant leaking out of this round "thing" (maybe blowoff valve) that is built into the hard coolant line running from my radiator, over the intake runners, towards the back of the engine bay. Here's a link to 3 photos I took this evening of the offending part:

http://www.dantesgiftbaskets.com/coolant/

Does anyone know what that part is, and why it would be spewing coolant?

Thanks in advance for any advice/assistance.

 

The part is a threaded plastic screw with a small indentation on one side that allows you to slightly open up the coolant passage to let air out when changing coolant. You may be able to just tighten it, but be careful. Mine snapped off at the top and I had to dig out the plastic and put a new one in. Dealer part, I think it was about 2 bucks. Check the o-ring on the screw to make sure it is not damaged.

Hope it helps. John

 

i had the same problem and replaced a lot of parts but it ended up to be a faulty o-ring. just a heads up

 

I replaced the bleeder cap screw today - the new one came with an o-ring on it. I'm going to post photos and a more detailed description later when I get off of work. Believe it or not, the head of the old one was sheared off from the get go, before I even tried doing anything to it, so just the threaded body was left intact, it was fun getting that out.

***

I didn't get a chance to take photos, but I want to describe the repair in more detail for anyone that comes across this problem.
1) I made sure the engine was warm/hot when I attempted removal of the old part, I did this so any plastic bits would flow out with the warm coolant out of the bleeder cap, instead of down into the system.
2) In order to remove the old part, since only the threaded portion was intact, I heated the tip of a flathead screwdriver with a MAPP gas torch (propane or acetylene also work) until it was red hot, then pressed it straight down into the middle of the threaded portion of the screw. I waited for everything to cool down, then turned the screwdriver counterclockwise to remove the threaded part of the screw. My part was plastic, so this technique worked, I've heard other versions might be metal, so keep that in mind. I can't take credit for this trick, I read it on another forum post, but I can confirm it works well.
3) Since the engine was warm, after I removed the threaded part, coolant started coming out of the cap at a good rate, so have the new part close by.