Corroding pipe - (Images)


Registered User
Jun 29, 2009
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Surrey, UK
Hi all,

Last week i posted about a problem i was having loosing all boost.
I found a possible culprit to this:
The image below (if i posted it correctly) is where i found a massive leak!
The circled pipe - the plastic one meeting the rubber one was not connected!


I'm not sure what this does (totally non technical) but i pushed them back together and used the jubilee clip to hold it.

After doing this instead of having no power i now get initial boost (perhaps a little late) and at about 3k revs sudden hesitation, it started as hesitation then boosting again after a second or so, now it seems to not quite boost 100% at all.
Pausing at 3k revs and picking up a bit but still not great.

The car is not running rough nor are there any problems under 3k revs driving normally around town.
Its just when you open her up!

I have a suspicion...
The pipe circled in the image below:


This whole pipe including the bit that was disconnected in the previous image is very spongy and highly warn... I dont know what it is or does (apologies for noob knowledge) But i believe this could be the cause?

What are your thoughts? could this be collapsing under pressure? (again i dont know what it does so maybe im wrong) or am i barking up the wrong tree?

Either way this is very weak and it needs replacing so any pointers as to where to get replacement or upgrade would be appreciated too.

Many thanks in advance

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similar problems have been covered in the last few days, the oil breather pipes degrade over time/use as they are exposed to oil vapours, end up getting blocked and splitting.

Basically need replacing as they break up and bits of rubber clog pipes, valves and end up in the sump will cause poor running, but also can pressurise the valve cover and cause valve cover and cam tensioner gaskets to leak/fail.

Forge do some replacement pipes, or just use r6 oil pipe and connectors, i'd have a proper check through of the breather pipes and pcv, ie remove and check for gunk/splitts etc....

Long shot but as your getting a misfire around 3k rpm, which sounds like a coilpack, check that the valve cover gasket hasn't leaked around the spark plugs and soaked a coil pack with oil.

Have a look at these threads too
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Wow that doesnt sound too good that it was totally disconnected.... no wonder it looks like theres a bit of oil around it...

Wont be driving that till its fixed :-S

Thanks for the information, i think i have found the bit i need to replace the circled rubber pipe - thanks to your links:

Forge Motorsport | Alloy Fabrication

Is that the correct replacement?

apologies for the lack of knowledge but the PCV is the hockey puck valve in the picture, correct? If so essentially what i want to do is replace the piping around it with the pipes in link above and check for gunk either side of it?

Then hook the new pipe up to the hockey puck and thats the degrading pipe issue sorted?

The coil packs for the 3k problem, ordered a new MAF so see if that sorts it first!

Then fingers crossed problem solved!

Anything else around the area i need to do too you reckon?

Many thanks
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Those forge pipes are for the pipes under the manifold, this is the one you'd need;
Forge Motorsport | Alloy Fabrication
have a look on ebay there was a selling doing them for about £5 less than forge

The PCV is a small valve under the manifold, the hockey puck is the PRV (pressure release valve) i got these two mistaken to being with

The problem is i expect your find that most if not all the pipes from the cam cover and PRV down to the oil return and PCV will be knackered. Have a look in the last thread of the three i posted. The rubber pipes actually breaks down so you can't clean them out successfully and the rigid plastic one become brittle and snap.

I ended up pulling it all out together with the PCV system and just replacing with some R6 pipe off ebay, about £30 rather than nearly £150 for all the replacement audi + forge pipes.


Have a read through the threads below, it is shows basically all the pipes which could be effected by degrading around that area, both breathers and pcv, if i were you i would remove the lot and spend the money on a catch can instead, as that is what i have decided to do, all these pipes fail in the end!!!

1.8t - PCV simplification and catch can installation - uk-mkivs

and here

I would also pull out the coil packs and check for oil, incase the valve cover has been pressurised or oil down the back of the engine
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You definately need to get under the manifold andcheck those pipes, as they are whats causing boost problems. Need to check the nonreturn valves are functioning correctly.
Great thanks for the information.
Looking at the catch can thread, looks a bit of a nightmare for me so may just replace all the piping.
I been looking on the threads and trying to find the correct replacement pipes on the forge site, found the cam breather hose (the one in my picture that I knew needed doing) Sportstractor - you mention the manifold pipes possibly causing the servere power loss - apologies for the noob questions but how can I find these pipes?
Is this link all the piping I need to replace the manifold pipe you speak of?
Forge Motorsport | Alloy Fabrication

So I replace with these two pipe kits and I should be good to go without worry of corroding pipe doing damage?

Thanks so much for your help so far!
Your not really gonna know until you pull the pipes out and have a look to see what is damaged.

To generalise I would say all the rubber pipes will need doing, hard plastic ones checking they not too brittle, clean and check valves.

Yep those are the under manifold pipes from forge, mine hadn't failed in the places which forge do the replacements for so would also of need the whole assemble from Audi ; 06A133789 £58

when i was gonna refit mine as oem with a few forge bits i was looking to get

t-joint PCV 058103247A
PCV valve 035103245A
PRV valve 06A129101A
oil breather down pipe 06A103213AK
under manifold VAC 06A133789
Forge 3 piece oil breather kit
Forge Cam cover breather
19mm dia 250mm long silicone hose
3mm silicone hose for fuel pressure

and possibly the right angle pipe oil return 06A103213F

I'm doing the catch can route to simplifly all this and reduce the cost

Pic below show most of the effected pipes below the manifold level
the Cam breather, oil breather down pipe and PRV are above manifold

part no. 058103247A joins the PCV and oil breather systems, PCV are the lower pipes in the pic

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Basically just have a look at it in your car then pull it all out and it will become much clear what pipes are needed!!
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Thanks for the detail. I'll have a poke around then and see what really needs doing to save overkill of doing everything.
I'll have a look tomorrow and see what's on the shopping list based on your picture.
Many thanks for the detail :)

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