Coolant leak

[Doofuss]

I need to get a new radiator for mine too but having nothing but problems getting/finding one!

The part number on mine is 4B3121251P which goes over to the F ..Which is the really fuppin expense one! It’s B/O at the factory and can’t find one for love nor money!

Tried the E and that ones no good.

[IchBautAuto]

Also judging by my lights, quite a big risk off snapping off the lower mounting points doing it without the bumper coming off. I have just made some replacement mounts which seem to have done the trick:

HeadlightMount.png
unnamed.jpg

Just done this again and modded the lights. Drilled out the bolt hole in the sheet metal above the lower outer securing bolt to 18mm.

Reduced the round peg and square locating tab length by half. The light can now easily be removed using a spatula to bend back the white plastic mount shown in your post,(It's very flexible) and sliding the light to the outer side before swinging the inner edge forward and out. The reduced length locating peg makes no difference as still engages fully. Only a few minutes now with nothing else needing removing.

[carlssonaero]

but how do we get a bufkin pipe as Bufkin no longer make them. How about this on ebay. I just asked the question on the message board if anyone used one etc and with what results?

https://www.ebay.co.uk/itm/Aluminum-Aud ... SwCyFbTP1-

julian

[Mɐʇʇ]

Looks the same.

[IchBautAuto]

It's a dead simple turning job for any machinist if you can't get one over the counter. I bought two not that long ago so if Bufkins are now off the market then it's only just happened. The only thing I recall is that you need to check the O rings as some copies didn't use the right product and you risk the same outcome as with the plastic pipe.

[steve2003rs6]

Just a quick update on mine.
Still no water leaking. Baffles me.
Radiator and hose to cooler connector was diagnosed as the problem.
Gave them the go ahead to replace the items.
Then radiator was no longer available and also one of the hoses.
Looking to get a rad made but haven’t lost a drop of coolant since.
So this repair on hold at the moment.
Audi gods seem to have smiled on me this time. But I really hate problems that “fix” themselves.

[Shoppinit]

Good call. Wait until it becomes a problem. And keep an eye on temps.

[steve2003rs6]

Yes Shop. Temps are spot on. Was checking coolant levels every week. Then every two weeks then every month or so.
Back to hardly ever checking it unless the bonnet is raised for some reason.

[Mɐʇʇ]

The coolant tank sensor is also decent at flagging a drop before it becomes critical.

[steve2003rs6]

Yes Matt. That’s how this all started. Was out for a drive then got the low coolant alarm come on.
But I never rely on alarms just in case a sensor goes faulty.

[Classik]

Just a quick update on mine.
Still no water leaking. Baffles me.
Radiator and hose to cooler connector was diagnosed as the problem.
Gave them the go ahead to replace the items.
Then radiator was no longer available and also one of the hoses.
Looking to get a rad made but haven’t lost a drop of coolant since.
So this repair on hold at the moment.
Audi gods seem to have smiled on me this time. But I really hate problems that “fix” themselves.

Hey Steve,

I've had the same issue with my former S6 and more recently (3 years ago) with the RS6, and I can definitely confirm the Buffkin pipe symptoms can vary from day to day. As I don't believe in self-healing mechanical problems, I suppose it has to do with how the pipe is broken inside the oil cooler and your luck of the day. Again I may be wrong when saying this is the explanation of your leaking issues, but it smells very much like it. In all cases there's a high probability it will fail at some point so if it were me it would be the first thing to do,
even before considering changing the rad and all surrounding hoses. As mentioned earlier, don't forget the oil cooler O-rings kit in the process.

[steve2003rs6]

Many thanks classic for the very informative details.
Yes I too hate problems that fix themselves.
If it is the bufkin pipe I can manufacture myself. And rather than ally I would use 316 stainless steel.
Still no leakage at the moment. From memory I went to unit 20 a while back for a service and coolant leak diagnostic. The bottom of the rad was covered in coolant leakage. IIRC THE Aux coolant pump was mentioned.
Parts could not be obtained.
Was looking to have a rad made from serck like a fellow member. Then leak stopped quite some time ago. Nothing since.
Just waiting to see how it goes but all good at the moment.
If I do end up making bufkin pipe. I will put a post on here in case any other members want one. Not a lot to them so would be fairy cheap to make. Also have a o ring company close by. Reckon I would use viton o rings instead of buna or nitrile. Either way the o ring company would advise me.
Fingers crossed it stays leak free ?

[Classik]

FWIW I bought this part (077117411A) from this vendor :https://www.ebay.co.uk/itm/Billet-Oil-C ... SwniRWN001. Never lost a drop of coolant since.
For the price, even if I had the time and skills I wouldn't bother doing it, except for the fun of course.

[HPsauce]

That might be the one I bought a while back.
Somewhere I have a drawing with the dimensions on, I'll dig it out and post it.

I suggest someone with a sample pipe to hand and suitable measurement tools verifies that, I can't!

[steve2003rs6]

HPsauce. Just ordered one from the info classik provided before I saw your reply. £21:67 including delivery from Poland. Many thanks for the diagram. If I need to I can now manufacture one from the dimensions provided.