Audi A4 Avant 1.8T - b6 A4 coolant loss

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Sun 26 Sep 2010 11:16
Audi A4 Avant 1.8T - b6 A4 coolant loss - 04a4
Good morning.

The issue concerns my wife's 04 plate avant. She informs me she is regularly topping up the coolant system... WITH WATER FROM THE TAP.

I have searched the Internet, done the relevant here, lifted the bonnet and uncovered what I believe to be the cause of my problem. I just need one final piece of information to be able to source and or fit the correct part.

Someone else had helpfully hosted some pics, so I will plagiarise his work, then help him find a solution to his (same) question.

Briefly, the situation looks the same as this...

www.dantesgiftbaskets.com/coolant/

Anyone able to let me know what this is and does? It's pretty loose, and liquid has pooled under here and stained the road, suggesting that after a drive and while the engine is off and cooling, it drips down out of here.

Appreciate any advice for a newbie!

Thanks
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Sun 26 Sep 2010 12:47
Audi A4 Avant 1.8T - b6 A4 coolant loss - Peter D

That is the bleed screw used when filling the system up. Try turning it to tighen it up. or obtain a replavement O ring and remove., clean and fit a new O ring. If you have been adding just tap water then you have diluted the pink G12+ Coolant so buy a 1ltr bottle and fill it up with neat G12+. Regards Peter

Edited by Peter D on 26/09/2010 at 12:51

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Sun 26 Sep 2010 13:12
Audi A4 Avant 1.8T - b6 A4 coolant loss - Peter D

Ensure the engine is cold when you remove the bleed cap. Do not allow too much coolant out or air in, get someone to help you with a thumb over the vent whilst you clean and fit a new O ring.. Refit the cap and top up the header with neat G12+ run the engie for a couple of minutes then turn off and release any air from the bleed cap and retighten. Regards Peter

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Sun 26 Sep 2010 13:27
Audi A4 Avant 1.8T - b6 A4 coolant loss - 04a4
That's great thanks a lot Peter.

Looking at it again, it looks like the cap itself has sheared off from the thread of the plastic screw, as I can see no way of tightening it. Or as a result, undoing it to get to the o ring underneath? (I'm assuming the cap itself should have some threading on it.)

Point taken about refilling with g12+.

Cheers


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Sun 26 Sep 2010 13:47
Audi A4 Avant 1.8T - b6 A4 coolant loss - Peter D

This may be a plastic cap and the top has cracked so you need a new one. Regards Peter

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Mon 27 Sep 2010 21:36
Audi A4 Avant 1.8T - b6 A4 coolant loss - 04a4
Hi Peter, thanks again for this info.

I have reverted to my local mechanic outfit who informs me that the plastic bleed cap system was replaced Round the time of the b7 with a new metal and Allen key set up.

Altogether much more solid sounding but, of course, the new metal cap doesn't fit into the existing plastic housing.

Therefore I need a new pipe itself, which is allegedly a bit of a b1tch to replace?

Even if I could find a new plastic cap the plug (I guess with the screw thread which I previously said must have sheared off) the cavity where the new plastic cap would sit has been blocked up.

Does the information that am getting sound consistent with your experience?

With regards
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Tue 28 Sep 2010 08:05
Audi A4 Avant 1.8T - b6 A4 coolant loss - Peter D

Yes I have seen both types. This is going to get expensive if the treads of the pipe are damaged. Regards Peter

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