2003 boost leak but no obvious hose leaks

J

Jonnyricer

Registered User
Joined
Apr 18, 2017
Messages
12
Reaction score
0
Points
1
Hi there new to the forum!
I have just bought a 2003 8l s3 really pleased however I have an annoying boost leak but only when demanding power quickly.if you gentle on the throttle it'll boost and feel ok.
I have checked hoses and and intercooler s but all seems OK.
There is a solonoid of top of the engine electrical connector connected but no pipes to and from it.
I do have a vcds which I need to plug in but there is no mil light illuminated.but does come on with the ignition.

Anyone else had such problems ??
It's done 137k Iv just done a full service on it includes fuel filter plugs etc.

Also I'm looking to remap it and ideally sports cathe and ss exhaust. Any recommendations I'm in bexhill east Sussex.

Any advice is much appreciated!!

Cheers
Jon
 
Welcome jon

So the selonoid you are talking about is the n249. Its better the way it is :rock:

Chec block 115 and compare specified boost with actual boost. But first check for any errors. If you never pulg in vagcom its "normal" that you see some errors, clear then and go for a spin,then check again.

As for the exhaust go with a 3" dowpipe and a 3" or 2,75" pipe(depending on your future power goals). I
ve both catback and resonator from magnaflow and couldn't be happier with the sound.

Cheers
 
Cheers I'll have a look in have heard air flow meters or fuel pumps can cause similar issues but the boost is bled by the actuator??
 
there quite an array of vacuum hoses which could be leaking - if you can see the N249 - it has probably been bypassed with a pipe from straight under the inlet manifold to the DV.

most of the pipes you can "sort of follow" - but a smoke test will highlight any leaks.

are you sure it is leaking and not just the turbo spinning up or an open cone filter? they are quite noisy? also some S3s still have forge splitters fitted (waits for forum ban).

I had a boost leak the other day (whilst trying to sort out something) and you can hear a clear whistle far too early for the turbo at about 1800RPM
 
Any pipe can leak but intercooler ones as std tend not to but anything is possible if its been messed about with

What makes you think you have a boost leak? have you logged boost in VCDS? do you have a boost gauge?

If its making boost by rolling on gently but not when pressed hard then you aren't leaking boost... a boost leak is a leak... it will be there no matter what..

Use VCDS to check for fault codes... you should also get a smoke test done as this will highlight any leaks you may have

<tuffty/>
 
Yep just trying to find the time to get into the work shop.
When I boost I can psssshhhhh and the it feels flat you know.the pipes I can see are all OK on a visual.
Another thought is the metal join ing pipe is a little corroded are these prone to fail.

S3 specialists in East Sussex?? Cos I can only hear the leak when rolling so might need a d rolling road !!
 
I may have solved the mystery found a Bretherton hose split behind the dipstick tube I moved it and there was an air leak and revs dropped.just orderd a set of silicone breather hose woop woop.
 
Any suspected boost leaks, get it smoked tested. It saves a hell of a lot of time, especially with the amount of vac hoses and crap to split and leak.
 
Yep boost leak sorted found 2 perished split pipes replaced with some creation motorsport hoses needed a fair bit of triming and we see how long they last.
Cheers all hope this helps.

Now onto the suspension!!
 
You must log in or register to reply here.

Similar threads

lukens3
huge boost leak but no codes?
Replies
2
Views
930
lukens3
lukens3
L
Pipe/Hose Identification - Potential Boost Leak?
Replies
6
Views
629
<tuffty/>
<tuffty/>
G
Perished hose on intake manifold / boost leak
Replies
3
Views
1K
bree9482
B
sideways steve
Boost Leaks - Solved !
Replies
0
Views
783
sideways steve
sideways steve
Audakas
Need some help whit air leak and boost leaks
Replies
2
Views
873
AARON77
AARON77
Top
Back