Diverter Valve, Smiverter Valve

[97AUDIA418TQ]

Hey guys, just wanted to share a recent experience I had.

I bought my car used and it always seemed a little "jumpy" and not as powerful as I thought it should have been. After doing some research I came across the topic of "diverter valves", learned how they are an intergral component of the turbo and etc. So i decided i was going to replace mine, maybe that would solve some problems.

Yesterday I swung by the local Audi dealer and picked up a Bosch 710N. Got home and popped the hood to install it.
(This sucker is located so deep in the engine in a tiny little area, it was a pain, but somehow I was able to work on it with only taking apart some of the plastic intake pieces)

Anyways, as most of you know, the DV has three valves coming off it, two larger ones and a smaller vacuum tube that connected to the headers.

Here is where the fun started. I grabbed a hold of the vacuum tube near the DV in my car and pulled on it a little to get some slack. Oddly, the tube seemed to pull easily and kept coming out as if it had tons of slack. ...

All of a sudden, the end of the tube flys up in the air and im looking at it in my hand.

THE DAMN VACUUM TUBE SNAPPED LONG AGO AND WASNT EVEN CONNECTED TO THE HEADERS!

Turns out the tube was EXTREMMELY dry-rotted. Just bending it at any position caused it to snap in half and practically dissentegrate into dust.

So in the end, i ran to the auto store. Picked up a new vacuum tube and clamps. Installed the new 710N DV. and my car now is twice as fast, and 5 times as smooth. Smoother shifts, smoother accel and decel. Smoother everything.


What a day.

 

[Dave_Cooper00]

Had exactly the same experience on a 4 year old Quattro. Vaccum line at the intake end was totally disintegrated from heat (and therefore useless).

Purchased and installed new vaccum line and the DV decided to work properly. I'm assuming the valve was continually diverting some boost with the vaccum line disconnected.

Now I don't trust the stock d_valve to be operating correctly due to age. Will likely replace with after market.

Hearing conflicting stories on performance impact. Some say new DV won't improve power (possible improvement in engine responsiveness) - others say they notice the difference. I figure it depends on whether your old valve is dead or not.

 

[philwest]

Hi guys. Is the stock diverter valve on a 1996 1.8T a round looking plastic part about 6 cm diameter, down near the turbo? I would like to try replacing mine but am not sure where it is.
I have the same sort of unsmooth performance that you have said and would like to check the vacuum lines etc.
Can you describe its position and appearance please?
Thanks.

 

[Dave_Cooper00]

DV's look like this...

http://www.a4stuff.com/performance_turbo.php

Boost from turbo enters valve from below and exits the side. Vaccum line attaches to the top..

 

[cbass]

Bosch makes a couple of different DV's and I have found one to be better than the other. Bosch's stock one that comes on the 1.8T engines is pretty bad, it is a diaphragm type, so it reacts quicker, but it is basically crap. The stock one is VAG part number 710A. Bosch also makes the DV's for porsche and the DV that comes on the porsche is the 710N and it is much better built and still a diaphragm type so you can get the quick response from it. It also has better flow rates, the diaphragm is tougher, etc. They are about the same price as a 710A also. All in all, I am very satisfied with my 710N. Here is some more information on them>>> http://www.s4biturbo.com/art-dvtests2.shtml Mike Shimon is the guy that I got mine from. He is great about shipping them and stuff, but I don't know how he would do international orders. Either way, I am sure you can find the same things over in the UK.
Good luck with it!
-Brad

 

[DavidR]

The 710N is the version stocked by main dealers in the UK.