I have a 2006 Turbo S. Primary and Secondary cat delete. Tuned. I have about 76000 now. I had replaced the diverter valves with an aftermarket pair around 36000 miles. For several months I have been getting strange pulls from the turbo. Spools up quickly (pegs on gauge) but does not go anywhere. Every once in a while it would hit hard.
So I stated looking at the general issues. Plugs and Coils, Fuel pumps; but just continued. This last weekend I started to look for vacuum leaks. Removed the aftermarket diverter valves and found that the drivers valve would stick open. This was allowing the boost on that side to just be dumped into the pre-turbo intake and not enter the engine. To make things worse the system is connected to only use the boost from the passenger side turbo to open the wastegates on both turbos. So the passenger side would pressurize and open both wastegate.
I haven't seen any discussion on this before on this forum. Some people have written about rebuilding the valves. These have a "lifetime warrantee" but I don't know what that does exactly.
Just one more thing to think about as these engines get older.

 

Who makes the aftermarket Diverter valves you're running ? Have you contacted then about the issue and the Lifetime Warranty?

 

That would be my first thought too. Although they are pretty simple, springs and a valve so could wear out.

 

I bet its one of those shuttle style valves that were all the rage 10 years ago.

 

They are EVOMS. As per other posts on this forum I have emailed and called but no response from them. Lifetime warranty should read buyer beware.

 

Anyone running the agency power ones?

Curious if this is truly even a necessary modification or not?

 

I ran twin 50mm Tial BOVs on mine. if the stock are leaking then good to upgrade, but if not, not sure it matters much.

 

Most of what I've seen is people of given up and going back to the Porsche valves . I think if you feel surging under power I would suspect the valves are sticking. No cel.

 

Been in the same boat. Leaking evoms. Went back to stock. I have a turbo s as well. Absolutely no problems with most updated part number factory diverters. Fvd tune and primary cat delete Installed on mine. Never been a huge fan of aftermarket tuning parts. In this case stock works and works fine. 🙂

No response from Evolution motorsports.

 

Did you just put them inline somewhere? Where is there room for 'em?

 

I think you have a bad maf sensor.

If you are seeing boost on the gauge there should be boost at the engine as the ecu and gauge both get their signal from the ecu via the maf sensor.

The ecu may be pulling timing and opening the diverters and wastegates due to a false overboost situation.

I would stick with the aftermarket diverters but they are meant to be pulled apart, cleaned and lubricated every so often to preset them from sticking.

 

Do you mean Boost pressure gauge? There are 2 MAF's in the car.

 

AFAIK even the lifetime warranty BPV's need some form of "maintenance" whether it be a regular cleaning or whatnot, was this being done?

I have the EVOMS ones as well and I've put on about 37,500 miles and have not had any issues as you're describing.

 

Sorry Map sensor.