Possible leak

[RobC]

I noticed when I looked under the bonnet yesterday that my undertray was showing signs of moisture in a large area towards the left hand side as you look at the engine. Interestingly I also had an odd looking area of condensation on the sound deadening on the bonnet directly under the belt, as if it were being ‘flung’ up by the belt at some point.

Got under the car and under further investigation it looks pretty wet on the underside of the boost hose but especially under the coolant hose - are the latter prone to leaking or the seals failing?

The liquid is almost gel like in consistency and has a green tinge to it which makes me think its not oil or coolant (as mines pink) so possibly air con?

Any ideas? 57 plate Edition 30 for reference.

[pudding]

Judging by the colour of the oil and where it's gathering, I'd say worn out O rings/boost pipe. Very common issue.  Engine movement wears out the O rings and pipe connections, so the choices of fix are:

Replace like for like, or:

Upgrade to the 6R/S3 intercooler and associated rubber hoses, which does away with the stupid bayonet clip connections in favour of good ol' jubliee clamps.

[RobC]

Judging by the colour of the oil and where it's gathering, I'd say worn out O rings/boost pipe. Very common issue.  Engine movement wears out the O rings and pipe connections, so the choices of fix are:

Replace like for like, or:

Upgrade to the 6R/S3 intercooler and associated rubber hoses, which does away with the stupid bayonet clip connections in favour of good ol' jubliee clamps.

Thats what I would have thought initially, except for 2 reasons - 1) Ive already replaced them in the last year or so! 2) When these go you tend to see a directional spread of oil on the hard pipe where the pressure is causing the oil to ‘spray’ out (thats what mine looked like previously and also a mates S3) but in this case its just a thin even coverage everywhere.

Messaged a mechanic mate of mine and he said from how Ive described it its likely aircon dye/oil. In the first pic you can see 2 star headed bolts and behind those sit 2 o-rings which are likely to have worn. In makes sense as it would help to explain how the residue got every, obviously the system itself is under pressure and so presumably its sprayed out covering the area, including the belt and hence why it was on the bonnet sound deadening.

Anyway, at least its not urgent and will get it picked up during my normal service in a month or so 

[pudding]

TBH I haven't seen air con oil that colour before, must be old and dirty!  Looks like engine oil but if it doesn't smell or feel like it, it could well be aircon stuff then!   Have you got a UV lamp?  Shining that onto the area would defo confirm air con dye 

[LC5F]

Is this pipe fully home?

[RobC]

TBH I haven't seen air con oil that colour before, must be old and dirty!  Looks like engine oil but if it doesn't smell or feel like it, it could well be aircon stuff then!   Have you got a UV lamp?  Shining that onto the area would defo confirm air con dye 

I think if it is Air Con fluid then its mixed with old oil/dirt under there from a previous boost leak although Im sure I cleaned this up!


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[RobC]

Is this pipe fully home?

Didnt actually notice that before. Will try and get under again this weekend and investigate.

Seeing as the clip is in place, is there any slack/movement in these pipes? Or is it possible the clip isnt holding it in place properly, so if I remove the clip, reseat the pipe and put the clip back in place it should be flush?


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[pudding]

That connection(s) is notorious for leaking.  It may look and feel sound physically, but hard boost with engine movement can cause those connections to weep boost pressure and consequently any oil from the breather that hangs around in those pipes.

This is why I'm a big advocate of the S3/6R intercooler upgrade as it does away with those stupid connections.  With one of those ICs fitted, you halve the amount of bayonet connections.  The one on the turbo never leaks as there's no movement there, but the hard pipe to intercooler rubber hose can leak if there's excessive engine movement.  it's not just the O rings that wear, it's also the pipe itself.   It's a process of elimination.  My hard pipe connection leaked constantly, even with new O rings.  Got a new pipe off ebay from a low mileage S3 and it's all bone dry under there 

[muff1991]

Hey @Pudding the hard pipe that comes down from the turbo and joins to the bayonet can be cut and replaced with a DIY hard pipe and silicone hose including a couple of V bands. I've got a mate who done this for less than a score. So if you have the 6R or S3 intercooler.. you would then have no Bayonets on the car.. unless theirs one more that joins the intake pipe to the intercooler on the passenger side, which thinking about it.. there is isn't there. But thats a good way of doing away with one of the damn bayonets. 

[RobC]

UPDATE - scanned the car with VCDS and have a 'Low refrigerant pressure' fault code or similar so it looks like it is the Aircon leaking.

Are TPS still open during these strange times?

[pudding]

I don’t think so. All of the dealers in my area are closed down and I’m still using the car every day, so I hope nothing breaks!