Loosing boost... :-(

[RS6-Croatia]

Guys, i have a problem... :-(

today i was boosting thru the city and sudenly i felt a los of boost...

At first i was thinking ok, right side tube from the turbo to intercooler is busted (last week i changed the right one because it bursted...) i will change it and will be ready for boosting again... BUT

I checked a tubes and pipes and all looks fine ????
I could not a find a hole and i hear it loosing boost somewhare...

Sound is coming from midle like form intake manefold, but i am not sure..

No Oil or other signs of leak... hm...

Anyone have experience with busted intercooler ??

Or maybe with blocked build in blow off valve??

It sounds like it is recicelying inside the intake, but to loud... on the other hand it must be leeking somewhere outside since i lost power and check engine come on...


When i press the tube from intercooler to intake and give a throtle i feal the pressure... so it looks like it is coming to intake and piping is ok..
Any known issues with intake maenfold it self?

HELP ???... :-(

[Duma]

koji auto???

[AndyBG]

C5 RS 6..., I presume.

[RS6-Croatia]

yes...

RS6 2003

[GrantG]

Does the pressure build up and die about 3k rpm or do you get no pressure build up?

[RS6-Croatia]

it`s build up... and die... i can feal the boost (when i squize the tube with my fingers) in ruber tube connecting the intercooler and intake... And i can hear it leaking somewhare like real loud bushhhhhhhh... like a wird blow off....

[GrantG]

Hmmm, ordinarily I would suspect either the N75 valve (common failure and cheap part) or BPVs. If you can hear it then I would get it pressure tested. My faulty N75 would allow the pressure to build up to between 3000-4000 rpm and then the pressure would be suddenly released.

Don't know if that helps.

Grant

[RS6-Croatia]

it helps a LOT.. thank you for your prompt answer !!

All i need now is to find it... :-)

[SpinEcho]

When my diverter valves failed, the symptoms were similar to yours and I heard a noticeable whistle.

[GrantG]

When you take the air filter housing off the top of the engine then the N75 is between the two rear air inlets (back of the engine). It's on a raised metal bracket and has 3 vaccuum hoses and an electrical connector.

Note, if you do replace it, make sure nothing gets in those exposed inlet pipes!

As SpinEcho says, I'd also check the BPV/DVs at the front of the engine under the removable cover, they are easy to test.

[RS6-Croatia]

TNX a lot !

I am aware that those tubes leads direct to turbo.. :-)

as soon as i get home i will test those and let you guys know, maybe it will help someone also... :-)

[RS6-Croatia]

SOLVED !

Right BOV was busted... constant open... now i am boosting again full power... :-)