WGVF hose disconnected

[Jas11n]

What problems would I have if the bottom hose from the WGFV to the coldside of the turbo was found to be disconnected ?
Just waiting for answers to see if I have found the HUGE hissing noise I could hear and a few other problems I've had with my purple monster this last week ( )

Jas

[BRY]

That would do it, hissing that is.
No boost above the spring load?

[kwlw]

What problems would I have if the bottom hose from the WGFV to the coldside of the turbo was found to be disconnected ?
Just waiting for answers to see if I have found the HUGE hissing noise I could hear and a few other problems I've had with my purple monster this last week ( )

Jas

Simple - you will get overboost cutout in most unpleasant way .

Sau

[Jas11n]

That would do it, hissing that is.
No boost above the spring load?

(With chips in) boost was going to 20/21psi in overboost, and holding before dropping at higher rpm.
(Standard) boost was going to 16/17psi in overboost and holding before dropping at higher rpm.

Simple - you will get overboost cutout in most unpleasant way

No overboost protection cut in with either chips. No fault codes on vag-com the 6/7 times I've checked.

[BRY]

Who's changed your spring then?

[S2central.net]

NObody has touched the spring !

WIth that hose missing, then the WG is never presented with boost pressure.

The only thing that would open the WG is when EXHAUST gas pressure gets sufficiently high to creep the WG open.

The main problem caused by this missing/faulty hose is loss of boost pressure - and yes I guess it would be audible hissing...

Paul

[BRY]

Everyday is a learning day!

[Greg_S]

Mark H had this happen to his car which gave a 2.X bar boost spike which may have caused his damaged pistons, because it came off when he was going on boost. Mark will be able to explain the situation better

[Jas11n]

Thanks chaps.
Yep, car felt really strange before I found this. It seemed to boost better, and pull better on 1/2 - 3/4 throttle than WOT.
Also with the chips in it didn't seem any quicker than standard even though boost gauge was telling me otherwise.
1st/2nd/3rd gear acceleration side by side with my bro was indentical, but 4th/5th/6th and he was slowly creeping away even though I was getting a higher boost reading than he was
The wastegate spring hasn't been touched in any way, still 100% standard, still got the seal on the top

Thanks again, I think I understand it now

Oh, would I have any problems if I extend the piping for the TBV so that it sits further up, rather than being buried down behind the headlight? 710N Bosch valve was only new 2 months but it was nearly holed due to rubbing. New Milltek one will resist that better with it being alloy, but I'd rather not damage it if I can help it (looks to bling for that ) and besides, it will look good if you can see it

Ta
Jas

[Greg_S]

Jas the original one that was on mine when I got it was well worn thru, you could put a pipe off of the cross pipe to the throttle body and have it in there if you wanted.

I have a Miltek one on there now with no complaints Which chips are you running? guess it could be a boost leak somewhere still giving you misleading info?

[kwlw]

Mark H had this happen to his car which gave a 2.X bar boost spike which may have caused his damaged pistons, because it came off when he was going on boost. Mark will be able to explain the situation better

Why ECU hasn't cut the fuel ? Sounds strange for me. Some modified chips ? From my expierence when that small hose drops off, cutouts are inevitable. Of course in stock config.

Sau

[Greg_S]

Sau,

Im afraid I dont know all of the ins and outs of it all so cant really answer that one.

[S2central.net]

Overboost protection only comes on when EXCESSIVE air has entered the system - meaning that unmetered air has got sucked in. Manifold pressure must be over a certain threshold to trigger protection mode. The source of this leak is such that any excess air sucked in under vacuum would be quickly expelled under boost - as it would easily blow out the open take-off hose from the compressor housing.

The other danger here is that the turbo could be overspinning in order to reach the target boost value - assuming its within range of WGFV adaptation of course... but Motronic has failsafes (IIRC) that provide limits on the WGFV adaptation to prevent this scenario... can't remember if that could/should trigger a fault code.

Paul

[Jas11n]

Thanks again for the replies

Car is sorted now, well, was yesterday after I hooked that pipe back up. Stock chips have been back in for a week or so. Never had overboost protection cut in ever, even on stock chips.
New Milltek valve makes a nice sighing noise when opening, also had a little chatter from it on the way home from work last night when lifting off throttle after a hard 2nd gear acceleration
The chips I was trying were those digitec ones Greg.
I'm leaving it stock "for now" but am planning RS2 upgrade sometime in the near future (when my bank manager tells security to let me back in the bank )
Anyway, car is now back to normal, makes it's boost at the correct throttle positions, no more snakes under the bonnet and drives just like the day I picked it up
Erm I'm having a bit of a fick blonde moment Not sure what you mean Greg? Could you explain a bit more about moving the TBV into another position?
I thought of just extending all the hose connections to the valve and maybe having it sit just in front of the airbox higher up.

Once again, thanks for the replies

Ta
Jas