From my experience the OEM plastic diverter valves wear over time and will not hold boost long at all. I now have new metal diverter valves which will hold .8 bar all day.


I also experienced another problem and it came down to leaking vacuum lines controlling the diverters. Rather than order the specific factory parts and wait two weeks for them to come from Germany, the dealer was able to get me out the same day using 7mm bulk hose that may actually be slightly thicker than the OEM hose.

 

Yeah, I had replaced the factory diverter valves once but put them back in because I seemed to have issues after swapping them. I'm going to put the new ones back in.

I have all new hoses and o rings on the way from the turbo to the intercooler and the two bellows hoses up at the intake plenum. I'm planning on pretty much replacing everything.

And yep I'm going to grab some generic silicone vacuum line and replace not only the diverter valve lines but also the waste gate lines too. And maybe even the boost control lines if I can get to them all.

Same thing with the hoses on either side of the diverter valves. Simple straight rubber hose and they want close to $40 each for Porsche parts. Don't think so, NAPA here I come.

The good news is I can almost replace the diverter valves with my eyes closed now. And I'm getting to know all the parts and pieces of this car WAY better.