Bl**dy boost leaks!

[Greg_S]

Finally has a chance to do a little bit on the S2 today since it has been neglected for the past month after fixing the cam cover gasket it developed a boost leak.

Went out there today and found it was the pipe from the inlet pipe to turbo to the cam cover.

So took it all apart and re fitted the pipe and went out for a spin and was running lovely, got 3/4 way home and on boost above .8 bar was getting psssshhh

Its too dark to go and try again now so I think I will have to fabricate a new bit of pipe work with a bigger lip on it and see if I can get some stronger hose clips. Any suggestions? they are the smaller 20-25mm clips. At least it happened after surprising an S4 & TT

[Greg_S]

got a few mins this afternoon so will try getting hold of some 22mm pipe to fit my catch tank at last and get this sorted.

[s2_bo]

Let us know how you et on Greg.
I hope you get it all sorted.
Bo

[Greg_S]

Managed to fix the boost leak today, found one of the leaks was on TB hose where it had come off underneath IM a little too so boost leaks fixed now. just goto fit catch tank next

[S2central.net]

@Greg - what catch tank / cyclone solution are you going for out of interest ?

I dunno whether to go for something custom made or the Audi item from the I5 TDi engines.

Paul

[A80Avant]

is it possible to hold 1.5bar at 4th,5th,6th gear and then 1.2 steady at the red line and have a leak that you hear as soon as you plug the hoses and put air in???
as i perform a boost leak test,as soon as i get 0.5bar of air in the hoses,i hear a hissing sound along with the air blowing in,but i cannot pinpoint the sourse.Could be the turbo itself.But im not having any problems with boost.

is this posisble?????

help!

please!!

[Greg_S]

Papvas, on mine it wouldnt hold any more than .7 bar boost with the leak, but wasnt gonna push it with the leak on there though.

With your leak it is likely to be a MAF hose or similar where as it expands it opens the crack/slit and lets the air escape.

@Paul,

I have a catch tank the same as Bo's from when they were made a while back but I havent decided how or where I will plumb it up as yet

[A80Avant]

Greg_S

thanks for the answer.Is it possible to reach 1.5bar with the engine running at various speeds,and when i try to push 0.5bar through the MAF hose have all that air escape???

Does the MAF to TURBO hose ever go at the 1.5bar figures?I suppose so,if this is a closed circuit of hoses and tubes,so if that is the case,why when the car is running i do get and hold 1.5bar and 1.2bar and with the incoming test air i cannot hold more than 0.5bar????

I have checked and double checked and secured the clips on the use of the test kit caps,and all of them where secured and tightened when i performed the leak test,so no air was coming off from them...

anyway the search continues...Besides it seems that my car does the most odd things among other S2-RS2s so this is why im not getting too much feedback!

[Greg_S]

Did you also block the PCV pipe when you did your leak test?

[Jay]

Negative

Does the MAF to TURBO hose ever go at the 1.5bar figures?I suppose so,if this is a closed circuit of hoses and tubes,

The Maf to turbo hose will see a slight negative pressure (vacuum) and will effect running if split but doesnt see the positive 1.5 bar. The 1.5 bar will be seen from the turbo outlet to the throttle body.

Try taking the hose off that runs from the turbo to the intercooler inlet (at the turbo) block here, the psv system and block the end at the throttle body... has the noise gone? (the turbo shouldnt leak internally, if it does leak across the bearing/seal it would leak oil, but could leak from a cracked cold side case) when you seal the system make sure the idle control valve pipe is blocked.

Jay

p.s just a thought if have you got a leak on your N75, waste gate system because that could cause a noise by the turbo???

[Greg_S]

Or it could also be a leaky DV

[A80Avant]

Ok,
here is what i have for the boost leak test kit.
I have 3 plugs,one is for the MAF to turbo,one for the hose that goes from the inlet manifold to the intercooler and one for the oil exhaust fumes,all three blocked i hear the sound.I was hearing the same sound even if i didnt block the inlet to the intercooler hose(cause i didnt have the cap yet).Still the air was leaking allover.

i didnt know i had to cover the ISV hose as well!!!

The turbo is NEW,the DV is FORGE 007 NEW,the N75 valve is also new and all hoses are Samco replaced....

i have no turbo oil leak,unless im burning oil from the turbo and this way i have no way of knowing that im loosing oil that way.I do have some small oil consumption but nowhere near the 1l on 1000Kms that audi supports ok to lose.

[Greg_S]

Pap, if you are connected on intercooler hose there is no need to block the ISV pipe. Have you done the 'mark H' mod on your intercooler cross pipe?

[A80Avant]

yes the 'H' mode has also been done!....

[Greg_S]

I know it might sound extreme, but try taking the intercooler to intlet pipe off and testing seperate to others and so forth so you can track down exactly where the leak is from