robbie_boy

Hello Everyone

I still kinda New to the Turbo scene and have only had my A4 for about a month now. And when i got the car there was no noise coming from the engine bay when i stepped on the gas but now it really sounds like it is sucking air.

It is really loud and i'am kinda getting nervous about it. What do you guys think this could be?

Could the turbo need a rebuild? I have 180,000 on the car and i'm pretty sure it could use a rebuild as i think it has some lag to it. Does anyone know where i can get a rebuild kit?

Thanks,

PwrDriftr

I've owned 3 turbo cars in the past and they all make a whistling kind of sound. Have you noticed any decrease in your car's performance? If so, your blow off valve may be stuck open.

robbie_boy

OK i notice the loss in power in around the 4,000 range

if it is the BOV then do i nee dto replace it or can it be cleaned?

Cheers,

PwrDriftr

Most likely replaced. The blow off valve has a strong spring on it to keep it closed. When you have boost pressure in the turbo and let off the gas, the boost pressure is strong enough to force open the valve and allow the boost to escape out the blow off valve. Over time, the spring can break and therefore the valve is always open and all your turbo boost is going out the open valve. This is why you hear the noise and do not get the turbo performance you normally get. But even for Audi, it should be "fairly" inexpensive to fix.

I hope this helps...

robbie_boy

Thanks very much

CHeers,

Sole_

btw a4s dont have blow off valves we have diverter valves

PwrDriftr

Does the diverter valve operate differently from a blow off valve?

a4rob

sole is right it is a diverter valve and i dont think the stock ones make any noise.

In our cars when you step on the gas you get a whistle, thats just how a turbo works.

But if you get a loud dentist drill type sound then your turbo is dead. Look around youtube for other dead turbo sounds and compare with yours.

http://www.youtube.com/watch?v=GFSiM...eature=related

robbie_boy

ok well from what i have seen on youtube my turbo is not blown i guess i will be more exact on the sound since i listened hard this morning.

It sounds like a really loud turbo spooling up. The Car seems to have the same pick up just the turbo seems louder around 2,600 rpm to about 5,000 when i shift. I will try and get a sound/video clip tonight if the weather holds up here

Thanks,

DuskBoBB

the diverter valve cannot open when your in boost! the spring dosn't do anyting for retaning boost pressur. the spring give you the range of vaccum you need for make it open. it just change how you need to release the gaz to open it. if your DV or BOV is install correctly the boost pressur push the side of the piston and the top of it so it cannot open. By the way if you got a OE DV, its made of plastic diafragm and it can broke on high boost or just by the time. A Forge DV or some kind of DV whit a machined piston cannot fail until its durty and stay open.



like a4rob said its maby some kind of loose in the turbo or it can be cracked like this




the turbine is cracked on many place and it do a dentist tool like sound. loose of boost by the way.

you can do another ting to se if its the shaft. put out the charged pipe of the turbo and take the compressor wheel and play whit it up down and push pull . if you see some kind of loose its mabe your center bushing that is gone.

sorry for my poor english. maby it can help.