hi new to the forum
please can you help i own a4 1.9 tdi 1997 afn i keep losing turbo power one min
and the next back again cold or hot and when i change gear
i have changed all vacum pipes put a new valve
next to the turbro i think it the n75 or contol pressure regulator i think it got at power chip fitted called powerlink all so think its got a new ish turbo it look to clean had the car 6 months
hope you all can help thanks stuart

 

maybe a bad DV

 

dont think iam thick put whots a bad dv

 

Couldnt wait to jump on the booze huh?? From what I gather, you are asking what a dv is... Its a diverter valve.. When you take your foot off the gas and the throtle plate closes, there is presurized air that is in the system from the turbo and needs a way out so it doesnt get forced back into the turbo and kill it. A dv diverts or routes that air elsewhere into the engine. SOme turbo'd engines use a BOV -blow off valve instead which lets that presurized air into the atmosphere when you let off the gas/throtle plate closes. It makes that "ppshhhht" noise. Most DV's dont make that "pppshhht" noise when its diverting the air because it goes right back into the engine and not out into the atmosphere.. A lot of jack asses want that "ppsssht" noise so they but a BOV on their audi which is BAD, makes it run rich (too much fuel) and ultimately will kill your catalytic converter among other things in the long run. So there is a valve inside your DV that can tear (its made out of rubber and is actually is more like a diaphram) and you will get inconsistant power/boosting if its bad.
Looks like this:

(you can see the valve/diaphram inside that opens to let the air through)

None of this may make any sense to you, but just kick back another, and pretend that it does.

 

thank you for your help. this has helped do you know where it is located
is the diverter valve part of the rocker cover or some ofter part

 

its under the car on the pass side