TroyN

I have some PET diagrams and posts here and I just can't tell.

On the below pic (borrowed from one of those other posts), what is the spade connector by the top arrow for? On my car there is no female connector connected.


Is what is pointed to by the bottom arrow the diverter? I have a housing that I removed (bottom pic) one of the end plates and can see that there is a piston held by a spring that, if pulled against the spring, would open between where the intercooler dumps into the throttle plate and the piping to the turbo intake. It would seem this would dump overboost back into the intake flow if some vacuum pulled the piston against the spring. However, again, in the PET it shows a diverter valve as a separate unit, and based on some descriptions in posts here it also would seem to be something else. So, what is it?? Thanks...

OSI930

That sending unit that you are pointing to is the overboost sensor. That entire assembly is typically called the recirculation valve assembly.

TroyN

So it sounds like there should be a wire connected to the sensor spade terminal? And it also sounds like the diverter is something else (is it the gold-topped part in the lower middle part of the pic?). I think the diverter diverts back to the intercooler, where the valve I have taken apart diverts back to the turbo intake. Right?

Thanks for replying, this forum is a bit quiet sometimes!

DWalker

Quite often the overboost sensor wire is "modded", which is a pretty dangerous thing to do. If you like Troy you can give me a call at 720-212-5838 and I will be happy to help you sort through all of this.

EDIT- Im probably not too far from you and could maybe swing by if need be.

JFairman

You have 2 diverter valves in that picture. They get called different things at different times, and a diverter valve diverts or reroutes air flow from one location or hose connection to another when vacuum is applied to the fitting that activates the valve.
The entire cast magnesium intermediate manifold is called a recirculation valve, blow off valve, or diverter valve depening on who is saying it and when. Even Porsche calls the blow off housing a diverter valve in some diagrams.

The other diverter valve in your picture is one of the 2 air injection diverter valves, and it is the small cast aluminum on with gold cadmium plated steel top, and it's in the center forground of your picture with a hose still attached.

The small sending unit you have pointed out is the overboost switch that disconnects ground to the fuel pump relays when boost goes over 1.3bar, shutting them off.

OSI930

Yes, that is the diverter valve in the lower middle part of the first picture. It is part of the emissions system.

TroyN

Thanks all, it's making much more sense now. DWalker, thank you, I'll give you a call tomorrow, great that you're local too.

Basically I'm experiencing a boost run-on condition when I lift off the throttle. I think I need to remove my intercooler so I can really see what's going on down there.

DWalker

Boost run on? Can you elaborate?

TroyN

I get a momentary surge when I let off the throttle.