Have reasons to suspect they are going, I have a 2.7t w/ APR 93 chip and the stock 710A Valves. How can I test them or see if they are bad?

 

I would assume they are bad. A couple of weeks with my APR and both of mine were torn to shreds. But to test them, take them out and push the diaphragm in with your finger and put another finger on the small hole on the opposite side. If the DV is OK, your finger on the hole should hold the diaphragm in place from the suction, and then will release when you take your finger off. If it is bad obviously there will be no suction at all. I wouldn't even worry about testing them becuase they WILL go bad soon. Get at least 710N upgraded DVs. Otherwise there are many aftermarket choices.

 

Ditto, those 710A's will go out or already out.

If you dont have enough cash for some Baileys or other aftermarket DV's go to your local Audi Dealer and order two of these: 06A-145-710N

They range from $40-$60 a piece.

 

If you really wanted to test the DV you need a small vaccum pump with a guage. Hook the vaccum gun up to the DV and see if the valve holds vaccum, if it doesn't it needs to be replaced.
Chances are the're already toast.