Boost hose leak

[Chesto18]

Replaced the 3 O-rings on the boost pipes to intercooler a few months ago, and two seals are behaving very well and seem to be seated properly with no leaks. Unfortunately the one on the front left of the car, (drivers side) sealing the pipe to intercooler, is not behaving.

Caught it leaking a while back and removed the O-ring, re-greased and refitted to see if that helped. Had the tray off for an oil change the other day and same thing, oil running from the seal and the pipe itself not seated flush against the intercooler. It’s not in danger of coming off as the clip is still keeping it in place, but it’s at least 1cm pushed out instead of being tightly seated as the other pipes are.

Is the only solution a new boost pipe here?

[pudding]

It's the intercooler.  That particular pipe connection always marginal at best. Probably why VW got rid of it on the S3/6R intercooler and used normal jubilee clamps.

[Chesto18]

Is there any reason I can’t use a silicone reducer pipe and two jubilee clips to get rid of this connection?

Just a short piece of silicone boost hose that’s flared one end to fit over the intercooler, other side going over the metal coupling on the boost hose.

If I can find one with the correct diameters would this not work?

[muff1991]

I have often wondered the same thing, but I think getting a hose over the intercooler part will be hard.

at some point I need to fit the forge hoses @Dave aka give me, but not sure if the couplers are any better than the standard ones!

[pudding]

I can't remember what the OEM intercooler looks like with the pipe removed.  Is there enough of a lip to get a silicon hose over it?  That should work.  I'm not sure what kind of horrendous turbulence that might cause, but worth a shot!

[muff1991]

I can't remember what the OEM intercooler looks like with the pipe removed.  Is there enough of a lip to get a silicon hose over it?  That should work.  I'm not sure what kind of horrendous turbulence that might cause, but worth a shot!

actually.. you saying that Pud, I don't think this would be a good idea! I had my head in there last night (fitted the forge coupler/hose - still not pleased, will upgrade intercooler sometime) but the inside of the intercooler pipe is the seating point for the hose/couler. almost like a circle within a circle... so air probably wouldn't flow very nice tbf.

[pudding]

Yeah that's what I was thinking.  A bit of a bottle neck!  The S3/6R is the best and permanent fix imo, and you benefit from lower intake temps 

[muff1991]

will defo be going for one of those!

[Chesto18]

I’d love the S3 option but ATM there are a fair few mods that would take priority.

I guess that airflow wouldn’t be as smooth with a silicone coupling but I’m wondering whether it would benefit overall anyway as the seal between pipe and intercooler would now be airtight. So whether a full seal is more beneficial than flow at this point.

I’ll measure up and see what my options are. The silicone reducers I’ve seen online aren’t expensive, so might be worth a go and see how I get on.

[muff1991]

I’d love the S3 option but ATM there are a fair few mods that would take priority.

I guess that airflow wouldn’t be as smooth with a silicone coupling but I’m wondering whether it would benefit overall anyway as the seal between pipe and intercooler would now be airtight. So whether a full seal is more beneficial than flow at this point.

I’ll measure up and see what my options are. The silicone reducers I’ve seen online aren’t expensive, so might be worth a go and see how I get on.

I suppose the best way to find out would be too try it.  Like you said, an air tight seal is better than nothing.
Tell you what I tried for a proper tight fit (and convinced it works): wrap a few layers of PTFE tape in the boost pipe groove for boost seal. This pads out under the boost seal making it a little bigger in turn... a tighter fit / better seal (grease seal for easier fitting) and make sure the seal slides in nice and straight and doesn’t try flipping off the pipe. It’s worth a try mate! Don’t go too mad with the PTFE tape otherwise you’ll never get it in lol. Find the happy medium unfortunately it will not stop the wiggle of the male and female joins but it will certainly
Help seal a bit if not completely! Let me know if this works for you.


Sent from my iPhone using Tapatalk

[Chesto18]

I’d love the S3 option but ATM there are a fair few mods that would take priority.

I guess that airflow wouldn’t be as smooth with a silicone coupling but I’m wondering whether it would benefit overall anyway as the seal between pipe and intercooler would now be airtight. So whether a full seal is more beneficial than flow at this point.

I’ll measure up and see what my options are. The silicone reducers I’ve seen online aren’t expensive, so might be worth a go and see how I get on.

I suppose the best way to find out would be too try it.  Like you said, an air tight seal is better than nothing.
Tell you what I tried for a proper tight fit (and convinced it works): wrap a few layers of PTFE tape in the boost pipe groove for boost seal. This pads out under the boost seal making it a little bigger in turn... a tighter fit / better seal (grease seal for easier fitting) and make sure the seal slides in nice and straight and doesn’t try flipping off the pipe. It’s worth a try mate! Don’t go too mad with the PTFE tape otherwise you’ll never get it in lol. Find the happy medium unfortunately it will not stop the wiggle of the male and female joins but it will certainly
Help seal a bit if not completely! Let me know if this works for you.


Sent from my iPhone using Tapatalk

That sounds like a plan! Will try that.

It’s only really that one connection that’s an issue. Other side of intercooler and the hose sides leading back to engine are fine. This one seems to not want to sit correctly even with replaced gaskets.

[muff1991]

I’d love the S3 option but ATM there are a fair few mods that would take priority.

I guess that airflow wouldn’t be as smooth with a silicone coupling but I’m wondering whether it would benefit overall anyway as the seal between pipe and intercooler would now be airtight. So whether a full seal is more beneficial than flow at this point.

I’ll measure up and see what my options are. The silicone reducers I’ve seen online aren’t expensive, so might be worth a go and see how I get on.

I suppose the best way to find out would be too try it.  Like you said, an air tight seal is better than nothing.
Tell you what I tried for a proper tight fit (and convinced it works): wrap a few layers of PTFE tape in the boost pipe groove for boost seal. This pads out under the boost seal making it a little bigger in turn... a tighter fit / better seal (grease seal for easier fitting) and make sure the seal slides in nice and straight and doesn’t try flipping off the pipe. It’s worth a try mate! Don’t go too mad with the PTFE tape otherwise you’ll never get it in lol. Find the happy medium unfortunately it will not stop the wiggle of the male and female joins but it will certainly
Help seal a bit if not completely! Let me know if this works for you.


Sent from my iPhone using Tapatalk

That sounds like a plan! Will try that.

It’s only really that one connection that’s an issue. Other side of intercooler and the hose sides leading back to engine are fine. This one seems to not want to sit correctly even with replaced gaskets.

It’s allwaayyys this connection that’s crap.. trust!


Sent from my iPhone using Tapatalk

[pudding]

Standard VW toolkit 

[Chesto18]

Reseated it with some PFTE tape around the metal coupling. Seems to be holding in tighter as you would expect but time will tell if it holds up.

On inspection the hose was again around 1cm away from flush and oil dripping out. And once reseated (as has happened every time I’ve reseated this connection) the car felt immediately more responsive at lower revs and generally torquier.

Hopefully this will work otherwise I need a permanent solution. 

[muff1991]

hopefully it holds up, if not... you can use @Pudding toolkit haha! or maybe try some heat shrink layers over the join too? As already mentioned.. it is the intercooler to blame.. they are rubbish and an upgraded intercooler will defo be on my list of things to buy next year!