Turbo Stall????

[Snoopie]

Just out of curiosity, I was driving home from work last night at a very low speed stuck in traffic. When the traffic free'd I pulled out to overtake a slower car, and realised all my boost had gone. I had noticed up until this... My dump valve from Forge was making a weird noise. I had no turbo whatsoever. I turned off the engine once stopped and re-started and the turbo was back. I presume this may have been Turbo Stall (Limp Mode) ....
Can this be caused because I'm using the wrong spring in a dump valve? I'm using the blue one, ideally should be running the yellow one?

Cheers

 

[Big_daddy]

could be, you should use the right spring for remamp type, the higher the boost higher tensity spring in the dv

 

[Snoopie]

I know which one to be using. But... I was sent the wrong one from Forge when purchasig my Dump Valve.

 

[Big_daddy]

well i know what u mean forge sent me the wrong service part for mines once, sorted it out evetualty.
should ring them up or email them, as if you use the wrong spring this could put strain on ur turbo life

 

[ElasticTangent]

I'd have though that if the spring was too stiff that you'd have this problem all the time Snoopie tbh. Is this a problem that you've only had since installing the new DV?

 

[Snoopie]

The dump valve decided to make weird noises all of a sudden. Then no turbo.. ?

 

[Big_daddy]

yeh the dv is jamming up, causing back pressure to the turbo! recommend u get it checked
keep ur right under control till it sorted

 

[Snoopie]

Cheers...

 

[Mitchy]

No a turbo doesn't just stall and remain stalled. As soon as you re-apply the throttle the waste gases will drive the turbine and re-spool the turbo.

A sticking valve will produce a ''wastegate chatter'' sound, and this is a result of the excess air flowing back the wrong way because the valve has failed to open and vent/recirculate the excess air.
As a consequence, it slightly stalls the turbo but will not stop it fully and that is why you hear the chatter sound. It sounds like a bunch of squirrels

Continued use like this will damage the turbo, so you need to clean/regrease your valve or replace it.

However i have no idea how you managed to lose your turbo for a moment as wastegate chatter happens every time you lift off. The turbo would still work and spin with accelerator applied.

 

[Snoopie]

A couple of fault codes registered - N249 Valve...... any ideas to expand on this?

 

[Songman]

A couple of fault codes registered - N249 Valve...... any ideas to expand on this?

The N249 valve is the small electromechanical valve which sits, on the LCR, underneath the top, decorative engine cover - it ports are connected by vac hose to the DV on the one side, and the inlet manifold on the other.

Upon command from the ECU, the N249 valve is switched, thus exposing the DV to the depression within the inlet manifold - this creates a vacuum inside the sealed body of the DV, and consequently the combination of forces acting on the DV piston are changed.

The DV spring pressure is defeated and the piston raises, alowing the redundant boost to relieve into the turbo inlet hose

You can often get a mechanical fault code register, when you change to an aftermarket DV - I think the code is 17608 - not too much to worry about.

It could mean perhaps that you try a slightly lighter spring in the DV.

 

[Snoopie]

Thankyou very much! That's the answer I was hoping for. I asked for a Yellow spring or even a Green one for my remapped Leon Curpa R... And Forge sent me the Blue spring. I believe this is the issue..