Oil Cooler Return Line Leaking - Options?

[R5YUG]

Over the last couple of weeks I could smell a feint whiff of oil in the cabin. I don't drive the car that often during the week and as it's been wet and cold I thought nothing of investigating until today… originally planned the day to replace the front pads!

Doh! - wish I had checked sooner, the whole undertray was covered in oil and nearside arch and wheel was splattered and cacked as well! – Oil wasn’t registering even on the dipstick – thankfully I haven’t driven far since I first smelt the problem.

Many frustrations later (too cold to be doing this kind of job outside) I discovered the cause of the leak. - The oil cooler return line appears to have either corroded or had a stone chip damage the line near where the plastic fog light cover is on the near side.
When I eventually cleaned off the mess I traced the smallest of pin prick holes that when under pressure was spraying like a geyser!

It was hard enough removing the bumper to do a temporary repair, quite proud of myself though I managed to clean the rust and gunk off the line and using an off cut of rubber pipe and some heavy duty jubilee clips I made a sort of pressure bandage that appears to have done the trick or at least stemmed the flow to not render the car useless. – Filled her up with only a litre so wasn’t as empty as had initially thought.

This looks like a complete b1tch of a job to replace, so has anyone suffered similar and gone an aftermarket route or got any tips to share for replacement?
In the attached from ETKA diagram it’s part 14 but it looks like it’s the wrong way round the bent end connects to the cooler and that’s where the hole is.

Any help gratefully received.
Guy

[Sql_RS4]

Been there, done that. It actually turns out to be quite popular problem with RS4s.

No idea if you can get anything aftermarket. I went with OEM replacement. Had to wait like a month to get it as they don't stock it anywhere as it is RS4 B5 exclusive part (that's what I was told).

VERY expensive for what it is. But it is a pleasure not to have oil stains in your garage floor, oil smell in the car or engine totally covered in oil when you notice it a bit late after some highway runs...

[RS4KILLA]

very common problem had the same £110 + vat from the dealers

[Sql_RS4]

110 GBP? Here in Poland it was around 900 PLN so more like 180 GBP if I remember right.

Pricy for what this part looks like anyway.

[Nige_RS4]

It might be pricey, but if it fails when you're driving and you don't switch off in time, you could destroy your engine.

I wouldn't risk driving on a temporary repair myself for anything other than getting it to a garage to replace the part.

[gareth215]

I did both on my RS4 as a precaution as the pipes looked old and worn, the parts where expensive but I did the work myself on a friends ramp and it was quite easy really. I left the oil cooler in place but took the bumper off. The main problem you will encounter is that there is a very high chance that the steel nuts on the pipes will have welded themselves onto the alumimnium oil cooler. If you use brute foirce chances are you will strip the soft aluminim threads. Instead I used a air hack saw and cut the nut until you could see the thread emerging and then spilt the nut open cleaned the thres and the new pipes bolted striaght on with no leaking.It is impotant to be very careful as otherwse you will damage the oil cooler threads and need a new one which IIRC costs 480 plus VAT. When you cut the nut id you do it very slowly you will see the threads appearing before you cut them it will make sence when you do it but difficult to explane! An easy job for any half decent garage no need for a specialist in my opinion, if it all goes tits up I know a good alumininium welder who may be able to put new thread on your oil cooler!

[Virdee Autos]

I didn't know the retrun line suffers the same problem.

All the one's I have seen have been the other pipe.

[tdiquattro]

I replaced the threads on the oil cooler with AN10 threaded ally male weld on ends, (cut the old ones off) the diameter of the hole is bigger. Then replace both hoses with goodridge or lined rubber 5/8 pipe.
That gives a better flow, a good fix and isnt much different cost than one audi pipe. will not corrode again.

[R5YUG]

Thanks for the comments gents -
I fully agree it's only a temp measure to get me about but I still need to use a car and as my R32 is still work in progress in the garage It's make the best of the situation... I like the idea of welding dash 10 fittings into the cooler too. Anyone know if the OEM fixings are dash 8 AN 8 ? - I just happen to have to aeromotive fittings and pipe that I could make use of.

Out of interest has anyone considered fitting an aftermarket cooler? I guess getting a thin enough MOCAL or similar item in there is somewhat unlikely for the expense of the bumper?

I guess I'll be swapping both lines then.....

[R5YUG]

Opted to get both lines replaced next week at MRC (mainly because I don't have the energy, space in a dry area or time to do it myself) - Fingers crossed the OEM cooler gets re-used issue free!
A ginger drive up there on the way to the Wirral me thinks with my nose on oil twitching duty....

[grizz]

You going to pop in for a brew ...?

[R5YUG]

I may well do Grizz - parents 50th Wedding anniversary and they are bound to do my head in after 1 day let alone the weekend! Fingers crossed I don't have a blow out this time and need to make use of your C spanners again!