## A4 - Coolant Loss - Advice required to fit part.##

[RickT]

Chaps,

Got a small coolant leak on the A4.. 2.0 petrol..

Following investigation i have located the leak, its at the rear of the "block" on a plastic valve which bolts onto the back of the head..

Today i whipped the air intake all and a few other parts to get to it to see if i could change it myself, ..

After looking at it, its looks like its going to be a nightmare of a job to do..

Below are some photos of the offending part, I'm going to do it tomorrow with my mate (who works for Audi :approve: ) but just wondering on thoughts regarding the best process to tackle it.

Photos below.. (the photos are not the best quality as taken on a camera phone)

Thanks in advance for any advice..

Rick.


First photo to give you an idea of the area we are taking about.... The "black hole" behind the block..

http://i148.photobucket.com/albums/s13/RickT_album/29022008128.jpg

The offending part... and hose.... The hose runs from there, into the section next to the battery and then into the bulk head.. (into the cabin)

http://i148.photobucket.com/albums/s13/RickT_album/29022008126.jpg


Possible leak around the sensor.... seal failure maybe...

http://i148.photobucket.com/albums/s13/RickT_album/29022008129.jpg

Coolant on the top of the gear box from the leak...

http://i148.photobucket.com/albums/s13/RickT_album/29022008136.jpg

http://i148.photobucket.com/albums/s13/RickT_album/29022008139.jpg




Another photo...

http://i148.photobucket.com/albums/s13/RickT_album/29022008134.jpg

[Crasher]

A real hand ripper to do, very tight and awkward and becoming common. :banghead:

[RickT]

Still not had chance to do this..

Loking at doing it Monday night now.

Rick

[RickT]

Just to let you know... problem now solved..

It was the seal around the sensor which had "disolved"

Replaced and re-fitted..

Jobs a good one!

Rick

[a4sportman]

Hi, I have 52 plate 2.0l petrol sport with same problem. I have allready replaced the sensor and seal, which solved it for a while. Now though there is a water leak from the black plastic housing itself. Upon removal, the whole thing is literally crumbling away. Awaiting replacement part arriving at dealers.

[fla]

what size seal is needed here - i assume its similar on the 1.8T as the 2.0? You wouldnt by any chance have a shot from slightly higher up to locate the sensor mentioned?

[RickT]

what size seal is needed here - i assume its similar on the 1.8T as the 2.0? You wouldnt by any chance have a shot from slightly higher up to locate the sensor mentioned?

Hi,

These are the only photos I have. The sensor is the green bit.

The plastic casing connects to the block.

Thanks

[nevo]

Its the temp sensor "O" ring you need £2 from audi

[vince70]

Or 75p from euro car parts lol, The O ring seal is the same seal as the one that's on the breather pipe.

[fla]

Just checked this on ETKA and it is an o-ring size 19.6mm x 3.6mm

[fla]

i've bought a replacement flange and seal for this. It looks very congested, what the easiest way to get access to te flange face to get at the bolts? I assume the rocker cover needs to be removed?

[Crasher]

Lots of bad language...

[fla]

Lots of bad language...better make sure either the elders or my kids are not around then ;)

[fla]

you were not wrong about the bad language! Changed the o-ring in the flange today, will post some pics shortly, although i didnt take as many as i would have liked. The old seal had gone hard and there was some deposits on teh back of the sensor so i guess this was where my leak was from. Took about 3 hours all in - about 1 hour to remove the sensor and about an hour to get the clip back in. The rest was not too bad.

[fla]

well it looks like teh seal is not the only culprit as i could see the coolant dripping onto the gearbox after it had warmed up, so it looks like the flange is going to have to be replaced. Great :( Problem is, how do you get to it? What needs to be removed? Looking at it on a basic level, ite seems that half of the back of the cylinder head needs to come out...unles there is a clever short cut?

[Crasher]

I thought that was what you had replaced. If you thought changing the sensor was going to make you swear, just wait until you try changing the flange, there is no short cut.

[fla]

Oh dear... what definitely needs to be removed and opened, Crasher? Would you be kind enough to label a few things for me on a pic of the bay? Mechanical work is fine for me, I dont really enjoy electrics though. Roughly how much time should i allocate to this? Thanks

[Crasher]

It is around the back of the head, impossible to photograph.