How do you tell if your diverter valves are blown?

I used to only get "honking" during HARD driving, in between shifts near the red line.

NOW, I seem to be getting a lot more honking. I was just out driving and, for example, I heard some honking as I partially let off the gas, in 3rd, during a very moderate pull (<50% WOT). Does this sound like my diverter valves are dumping boost prematurely?

Thanks

 

he bud can you pull them out quickly and pressure test them? I've seen one or two EVER that actually got stuck slightly open. I guess not enough grease inside or something. I doubt they are but hey stranger things have happened. You're sure the "honking" isn't more an "airy whoosh" as you let off of the gas?

 

The odds of popping an oring in the valves is next to none. There is not a whole lot to wear in there.

 

Thanks for the response guys. I'm going to get a pressure test done when my intercoolers arrive. Would this test detect a bad diverter valve, or should they be tested seperately?

 

Alex & Stephen -- I am ignorant in all things automotive, so I'm a bit confused by the difference between "honking" and the "airy whoosh" as potential signs of bad DV's. The ads I see for new DV's usually talk about eliminating the "honking" that you can get with the factory Bosch DV's, so I would think that "honking" is a sign of failing DV's? Would the "whoosh" sound be escaping boost (normal or abnormal?)?

Please try to excuse my ignorance, but I'm just curious as I plan on replacing my Bosch DV's with better ones soon, and I figure if I screw it up and have some leaking hose -- how will I know? I have an '01 996tt, and I hear neither a "whoosh" or "honking" currently.

 

Air whoosh is normal. Remember that when you throttle off all the air built up in the system releases from the valves the minute you throttle off. The honking noise is generally caused from the factory DVs splitting the rubber diaphragm and vibrating past the split in the rubber. It honks verses a whoosh.

On the factory DVs, it is not if they fail but often when.

 

Stephen -- Thanks for the education. I just noticed that Zippy has your IA GT700 upgrade, so he (and you and Alex) was (were) talking about his billet DV's, and not my poor quality factory DV's. Sounds like you are saying the billet type DV's rarely if ever fail, and the factory ones almost always do. Any recommendations on where to buy the billet type DV's (EVO or Bailey's?)?

 

You are correct.

Where to get them.... I bet I can help with that

 

Yes you can Stephen, just checked out your website and saw them listed for sale. Thanks.

 

Does anyone have a sound clip of the honking? I occasionally hear a screech when I shift from 1 to 2 not all the time.

 

Tonight my car started making a "hooting" sound, rather a "honking", I'm now only making .6 bar compared to the usual .7-.8? Failed DVs?

 

Usually a check engine light will be on when the diverter valve fail.

 

I pressure tested my car ans the DVs were both leaking bigtime...

 

ok this is the last time i'm asking... my car used to make the grear wooosh sound . then i added the larger fresh air intake sys ... (starts behind the airbox and runs o the turbos. the car is way faster buuuuuut the great woosh sound is gone not a hint of woosh whats the deal???

 

Markski -- What type of DVs did you have that were leaking?