Diverter Valve Failures
#1
Three Wheelin'
Thread Starter
Diverter Valve Failures
Hi Gents...My Turbo build is complete. Had some delays for the past several weeks chasing vacuum leak issues (real or perceived) during the tune process and then things really went sideways when the RPM would marginally increase when the throttle was released. This issue was eventually diagnosed as failing diverter valves (new Forged diverter valves had been installed as part of the build) and the OEM DV's were reinstalled and Walla! All problems disappeared and the heretofore drivability/throttle application issues were also resolved.
Just curious if anyone else has experienced DV failures and if so what your symptoms were (I am kind of kicking myself as I was the person who requested the Forged DV's when we put the build list together).
My car is being shipped back Thursday and I am really looking forward to some seat time.
Just curious if anyone else has experienced DV failures and if so what your symptoms were (I am kind of kicking myself as I was the person who requested the Forged DV's when we put the build list together).
My car is being shipped back Thursday and I am really looking forward to some seat time.
#2
Rennlist Member
Everything I've read is that the stock DVs work well and there is no reason to change them. Maybe if you are going for a much bigger build they make sense. Didn't you upgrade your turbos, too? Which ones did you get?
Kinda like headers, most everyone says the stock ones are pretty darn good unless you get into the 800+ or more HP builds..
Kinda like headers, most everyone says the stock ones are pretty darn good unless you get into the 800+ or more HP builds..
#3
Hi Gents...My Turbo build is complete. Had some delays for the past several weeks chasing vacuum leak issues (real or perceived) during the tune process and then things really went sideways when the RPM would marginally increase when the throttle was released. This issue was eventually diagnosed as failing diverter valves (new Forged diverter valves had been installed as part of the build) and the OEM DV's were reinstalled and Walla! All problems disappeared and the heretofore drivability/throttle application issues were also resolved.
Just curious if anyone else has experienced DV failures and if so what your symptoms were (I am kind of kicking myself as I was the person who requested the Forged DV's when we put the build list together).
My car is being shipped back Thursday and I am really looking forward to some seat time.
Just curious if anyone else has experienced DV failures and if so what your symptoms were (I am kind of kicking myself as I was the person who requested the Forged DV's when we put the build list together).
My car is being shipped back Thursday and I am really looking forward to some seat time.
when were your leaks apparent? idle?
#4
Rennlist Member
The Forge pistons ones can cause all sorts of issues. They can get stuck in the cold weather, jam up in hot weather/temps, leak from the o-rings twisting around. I have always just run stock diaphragm style ones without issue.
#5
Three Wheelin'
Thread Starter
Everything I've read is that the stock DVs work well and there is no reason to change them. Maybe if you are going for a much bigger build they make sense. Didn't you upgrade your turbos, too? Which ones did you get?
Kinda like headers, most everyone says the stock ones are pretty darn good unless you get into the 800+ or more HP builds..
Kinda like headers, most everyone says the stock ones are pretty darn good unless you get into the 800+ or more HP builds..
Last edited by usrodeo4; 12-19-2018 at 11:51 AM.
#6
Three Wheelin'
Thread Starter
We had 3 or 4 leaks identified; some manifested themselves with rough idle and one was mid rpm ~4k rough throttle, then the last issue was RPM increase after the Go pedal was released. The leaks were throttle body hose, o ring in one of the diverter valves, a bolt screwed too far in one of the intercoolers that caused a loss of pressure and possibly a fuel regulator hose. Sam at ByDesign felt the failing diverter valves may have been contributing factors all along as once they were replaced with OEM DV's even his base tunes were almost perfect. The silver lining to the cloud is the car was thoroughly pressure tested multiple times.
#7
We had 3 or 4 leaks identified; some manifested themselves with rough idle and one was mid rpm ~4k rough throttle, then the last issue was RPM increase after the Go pedal was released. The leaks were throttle body hose, o ring in one of the diverter valves, a bolt screwed too far in one of the intercoolers that caused a loss of pressure and possibly a fuel regulator hose. Sam at ByDesign felt the failing diverter valves may have been contributing factors all along as once they were replaced with OEM DV's even his base tunes were almost perfect. The silver lining to the cloud is the car was thoroughly pressure tested multiple times.
Oh trust me....I have been dealing with a "leak" of some damn sort for months now. Ordering my oem valves now.
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#8
Three Wheelin'
Agree, I previously used Forge DV's and returned to stock. OEM's are plastic whereas Forge are metal. IMO that's the only difference and contrary to popular belief they do not increase horsepower.
#9
EVOMS sells the metal cap and a stiffer spring to use with the OEM diaphragm setup.
#12
I also found part which is goes from back of the plenum...and then tees off to the AIR injection system and also controls the diverter valves. I wonder if when faulty is also causes leaks.
9A1-605-165-00
It is cheap enough to replace....so i think Io am going to replace as well.I keep getting P2187 and P2189 CONSISTENTLY....but it is intermittent. Sometimes car is horrible to drive and others it is fine. Luck of the draw when it starts up....so it has to be some sort of valve failure (electrical at that).
#15
Originally Posted by usrodeo4
The last drivability problem that was so vexing that was fixed by installing the OEM DV's was not throwing a code.
Last edited by Turboslut; 12-27-2018 at 11:05 AM.