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bigrobby
08-30-2009, 01:51 PM
99.5 a4 1.8t MT APR 93 octane 170k

i finally got a 710n diverter valve (used for less than a year) and i could immediately tell a difference in power after shifting.

anyways...the car has a moaning noise now....only under very light throttle....boost gauge reads about 5 in hg.

now i've heard that before on a bad diverter valve...a valve with a small vacuum leak can be struggling to open at 5 in hg which creates that moan..............however...i put a vacuum pump on mine and it held 27 in hg for about ten minutes. i also put the pump on the hose from the manifold and no vacuum leak. i made sure the hose is back on the manifold tight....it is no going to leak at that connection. still moans

so i'm prepared to just replace the diverter valve because.....after all....it started making the moan after i installed it.....however i just wanted to make sure i'm not missing something. i dont know why a DV with no vacuum leak would make that noise. dont know if there could be a problem with the spring in the DV or what.....just seein if someone else knew

thanks

old guy
08-30-2009, 02:21 PM
Try reversing the DV and see if the noise goes away.

Clicky click (http://dv.mistertam.com/7.htm)

CrtchRktRcr
08-30-2009, 02:29 PM
Could it need to be greased?

old guy
08-30-2009, 02:36 PM
The 710N is non-serviceable. It is a diaphragm DV, not a piston type DV.

bigrobby
08-30-2009, 07:24 PM
reversing it seems like boost psi would push the diaphragm up which would kill the boost.....unless i somehow have the thing backwards....but i dont think i do. i'll check....obviously the opening at the bottom of the DV needs to be on the non pressurized hose...

but assuming i'm not an idiot.....and other ideas?

old guy
08-31-2009, 02:36 AM
reversing it seems like boost psi would push the diaphragm up which would kill the boost.....unless i somehow have the thing backwards....but i dont think i do. i'll check....obviously the opening at the bottom of the DV needs to be on the non pressurized hose...

but assuming i'm not an idiot.....and other ideas?

Go back to post #2 and read the article. Also read this thread: Clicky click (http://www.audizine.com/forum/showthread.php?t=306204&highlight=710N) Pay special attention to diagnosticators comments on DV noise.

j2da
08-31-2009, 08:53 AM
bump for same issue here with 710n, and if i reverse it it makes a different but even worse grunting noise. also only happening around 5hg - 0psi. im gunna read those links and see if anything pops up

bigrobby
08-31-2009, 07:26 PM
alright so according to the article and the thread the links led to..... the correct setup for a 710n is "reverse" with the bottom of the dv going to the charge pipe.

this is how it's been set up all along.....

i switched it anyways though....now the charge pipe end is going into the side of the cylinder on the DV

noise still exists but is different and substantially quieter. its hard to notice now. but still it's not right obviously. and according to guys who know....the current quieter setup is wrong.

add that to the fact that it holds vacuum perfectly and is not too old and it has me pretty confused. i guess in theory the spring could be weak but i doubt it...and it feels stronger than a new stock one still.

bigrobby
09-01-2009, 01:26 PM
anyone know?

j2da
09-01-2009, 01:34 PM
did the noise change from a moan at 5hg-0, to a lower "grunt" around 10hg after you reversed? beacuse thats what happened in my case.

im in the middle of the same annoying issude, what im going to do is bypass the n249 (do a quick search on it), and run my dv straight from manifold. i dont know if thats even the problem but i have heard the n249 can cause the dv to do that on dbw cars. and id rather bypass a pointless valve than buy another diverter.

dont quote me either haha, but ill be sure to post after i delete the valve.

old guy
09-01-2009, 04:11 PM
anyone know?

There is no "right" or "wrong" way to install it. Whichever way works best for your application is the "right" way for you.

bigrobby
09-01-2009, 07:47 PM
did the noise change from a moan at 5hg-0, to a lower "grunt" around 10hg after you reversed? beacuse thats what happened in my case.

im in the middle of the same annoying issude, what im going to do is bypass the n249 (do a quick search on it), and run my dv straight from manifold. i dont know if thats even the problem but i have heard the n249 can cause the dv to do that on dbw cars. and id rather bypass a pointless valve than buy another diverter.

dont quote me either haha, but ill be sure to post after i delete the valve.

maybe in 2000 when they switched to ATW there's a solenoid in between....but on my car the DV does run straight from the manifold. the sounds with it "reversed" was a lower louder moan. now with it on forwards its a much more subtle moan that sometimes pulses....its weird. and when i turn the car off i hear a final poof that i never heard with the stock DV

bigrobby
09-01-2009, 07:50 PM
There is no "right" or "wrong" way to install it. Whichever way works best for your application is the "right" way for you.

i think as far as performance is concerned i found the best install for my car....so thanks for that tip....but i still don't get the noise considering the DV holds vacuum well.

I'm not bein cheap here....i dont mind buying a new 710n . i just dont wanna do it if the noise is gonna return.