Popping boost pipe joints - a cheap fix....

muddyboots

Still hanging around
Oct 16, 2002
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OK, as many will know, the inlet/boost pipe fittings used on the VAG TDIs are prone to popping apart.
If the two small retaining lugs on the end of the pipe get worn or damaged, it's often a downhill slope - once it's happened, it's quite likely to happen again. Each time the joint comes apart, the more damage gets done to the lugs, so it's a vicious circle.
And because of the design of the joints, you can't use jubilee clips...

I've recently had the problem on my Passat (PD130).
One of the pipes runs from the engine, to the top of the (side-mounted) intercooler.
I started having allsorts of problems recently - hesitancy, smoke etc but oddly, no warning lights, fault codes or noticeably power loss either. I could hear the turbo much more clearly than usual.

Turned out the hose into the top of the intercooler had partially blown off - one side had blown out, but the other side was still held in, so it was at an angle and although losing a fair bit of air, not enough to trigger any faults.

I refitted the pipe and the clip, however I noticed one of the pipe lugs was quite worn.
Took it out for a drive, and it popped straight off again.

Options:
1) Buy a new pipe, and new clip. Pipe will probably be quite pricey. Nowhere open I can buy a pipe from before I need the car on Monday.
2) Try an alternative means of pipe retention...and if that fails, revert to option 1.

So - an alternative means of pipe retention...

I refitted the pipe in it's normal position.
Using a dremel with a 2-3mm drill bit, I drilled two holes through the outer plastic housing of the "socket", going just far enough in to mark the metal of the pipe tip.
Disconnected the pipe, stuffed tissue in the 2 open pipe ends to keep swarf out.
Used the dremel to drill through the metal pipe tip where the marks were.
Cleaned everything up.
Refitted the pipes and horseshoe clip.
Screwed 2 small self-tappers through the holes in the plastic housing, and through the metal pipe end inside.
So - pipe is held in by the horseshoe clip, and also 2 screws.

An easy job to do, and went out for a drive giving it full beans up numerous hills - and it's still in place.

Because the rubber seal is right at the end of the pipe tip, the holes are "behind" the airtight seal - so if I do ever replace the pipe, I can just slot the new one in with it's horseshoe clip and no problem with the holes being there.
Also, the 2 screws are easily removable should I ever need to remove the pipe.

Let's see how it goes in the longer term, but this could be a cheap & easy fix for knackered pipe joints....
 

muddyboots

Still hanging around
Oct 16, 2002
5,739
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So far so good.
Over 100 miles now, plenty of full-boost application and pipe is holding nice and tight.
 

skullmunki

Ding Ding Round 2!!!
Nov 12, 2006
502
0
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Glad to hear it's working well :)

It's an idea to bear in mind and thanks for going to the effort of sharing it with us :thumbup:
 

MJ

Public transport abuser
Apr 22, 2008
5,508
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Manchester
m.facebook.com
Its how we've fixed many at work - as long as you get one on either side it should be fine however we have had some which have blown the seal past the pipe due to the little gap, just a rubbish design really.
 

muddyboots

Still hanging around
Oct 16, 2002
5,739
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Its how we've fixed many at work - as long as you get one on either side it should be fine however we have had some which have blown the seal past the pipe due to the little gap, just a rubbish design really.
Couldn't get one either side as that would mean removing the bumper & intercooler, and I had no time (or inclination as it was well below freezing!).

I put two screws in as far apart as I could get my dremel in to drill the holes.
One of the pipe retaining lugs was still intact anyway, so it's being held in 3 places now.
Can't see it moving with those screws in, not without the plastic housing snapping off anyway :)
 

Husbandofstinky

Out from the Wilderness
Nov 8, 2007
1,515
12
Temperate Regions
The next fix will be 'No More Nails' (someones bound to do it!)

Seems an obvious quick fix when you think about it.

The only problems as ever will be access (as mentioned already), also the state of the self tappers should you ever need to remove them. Stainless steel ones would be ideal.

Good heads up given the effort and expense involved.

I know what you mean about time and inclination as I had the rear tailgate panel off the Pug this arvo. Previous owner fitted aftermarket speakers very poorly - alsorts of crackles/feedback.

It was a case of stripping back and starting over but bugger when the sun went in and the wind picked up hands were chuffing freezing - not fun.
 

jonjay

50 Years of 911
Jun 27, 2005
5,843
1
Essex
I personally don't think that solution will work on pd150 as where the pipes pop off and split is where they attach to the intercooler. Putting self tapping screws into that plastic fitting may end of causing more problems further down the line. This is not to say you are wrong as it clearly worked well for you.

I have gone down the route of getting a full alloy system which is being professionally made as we speak. The only points of failure I can see with the new system is the small silicone joiners connecting the alloy pipework to the intercooler. If they do perish at least they will be cheap to replace with minimal effort.

Roll on all alloy turbo outlet pipe :)
 

muddyboots

Still hanging around
Oct 16, 2002
5,739
1
I personally don't think that solution will work on pd150 as where the pipes pop off and split is where they attach to the intercooler. Putting self tapping screws into that plastic fitting may end of causing more problems further down the line.
Should work fine - it's the intercooler joints that I used this technique on, and so long as you suitably pre-drill the plastic, nothing should break.
They're also in such a position that should you wish to fit a new pipe, you can remove the screws and the holes they leave behind are "outside" the seal, so no air loss. All carefully thought through ;)

It's been working 100% fine on mine for over 6 months now, or in terms of distance - around 10,000 miles :)
 
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tinky

Active Member
Apr 13, 2010
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0
Thanks for advice, might come in handy one day (hope not). But i did think of another way, didn't do it in practice tho. Clip seems to pop off the lugs because their edge gets rounded, and it sits on it at 90 degrees angle (hope you understand what i mean). If you file that lug down a bit, mainly at the base of it, it would create sharper angle and any pressure would be pushing clip IN, not off the lugs. Again, just a theory, but i'm quite sure it would work.
 

muddyboots

Still hanging around
Oct 16, 2002
5,739
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Thanks for advice, might come in handy one day (hope not). But i did think of another way, didn't do it in practice tho. Clip seems to pop off the lugs because their edge gets rounded, and it sits on it at 90 degrees angle (hope you understand what i mean). If you file that lug down a bit, mainly at the base of it, it would create sharper angle and any pressure would be pushing clip IN, not off the lugs. Again, just a theory, but i'm quite sure it would work.

Yes I completely understand your theory.
However from my recollection, the lugs are thinner and more fragile than you expect - I don't think they are solid, just pressed outwards from the main metalwork, so are effectively hollow. On one of my pipes, on my Ibiza a few years ago, I seem to remember one lug wore right through and had a hole in it, on the flat face (whether that was from normal use, or because I'd tried your technique of filing the face flat again, I can't remember!).
So I suspect if you start filing the edge of a lug flat again, it'll make it weaker - it might even start to wear right through. In that case perhaps a bit of work with some Chemical Metal or similar may help :shrug:
If you try it, I'd suggest using a new clip as well, for 2 reasons: 1) It'll be a bit stronger than the original, and 2) It'll have flat/square edges - whereas the original clip will probably have rounded a bit.

It might work, for how long though I'm not sure; If you want to be completely confident it won't happen again - my suggestion is a more "positive" method of retention such as screwing in place.

Finally - when reassembling using the normal clips, it's vital you *fully* push the pipe into the socket first, before you put the clip on. Depending on where abouts on the car the joint is, how uncomfortable/cold/wet the ground is you're laying on, how little light you've got to see what you're doing, and how caked in oily shite the joint is - it's sometimes easier said than done :)
If it's only part way in, the clip won't sit behind the lug, more likely on top - which means the pipe will pop out again. Or if you then push the pipe fully in place after the clip has bene fitted, the clip will probably damage or round-off the lugs and you'll be back to square one.

I bet there are many pipes that haven't been properly refitted following other service work, which go on to cause failures. Even a Seat main dealer once failed to refit a pipe correctly on my Ibiza (one has to be removed when doing a cambelt change). On the drive home it popped off under boost. Even though it had never happened before in the first 60,000 miles of my ownership, they tried to tell me it needed a new pipe and would charge me ££ for it. I drove it home gently, carefully reassembled it *properly*, and it was fine...
 
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muddyboots

Still hanging around
Oct 16, 2002
5,739
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Nice and shiny, but my approach does have the advantages of A) being free and B) allowing use of the existing hoses as they are ;)

I say free, I am of course assuming you can find a couple of screws knocking round in the bottom of your toolbox/kitchen drawer/nuts'n'bolts box/shed/garage.
Like being able to sharpen a pencil with a stanley knife, and posessing a collection of useful bits of wood for "stirring paint", any man should have a random collection of screws readily available somewhere :)
 

S3 AKR

livin' the dream!!!
Jun 30, 2004
1,453
1
Colchester, Essex
Another cause found on my car for the hose joint at the intercooler on the passenger (...the left for our European friends!) side that kept popping was that the spring clips themselves were slightly different sizes and fitted to the wrong ends of the pipe. Its been about 3 months without any issue (tempting fate stating that openly).
 
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