today i was driving and the low oil pressure warning came on and i shut the engine off immediately.i pulled over and started it and after a few seconds running the top end of the engine started to squeel. the oil levels are fine and the oil is only 500 miles oil with mobile one synthetic.i got it towed home and started it again and tried to remove the oil filler cap and it wont come off because of so much vacuum.once i got it off while it was running it wouldn't run it will just stall. so i pinched off the pcv system by pinching the second vacuum line on the intake and it runs great. i am thinking that it is the t- valve which has 2 check valves on it but i am not shure.and help would be really appreciated.....the audi is a 2004 audi a4 amb 1.8t with a cvt trans.. hopes that helps thank...and it has exactly 66,600 miles on it........

 

i saw something about this on audizine.

 

i think it is that t-valve otherwise known as the pcv because it is supposed to regulate the amount of vacuum that is in the crankcase.i took the valve and it has flow back and forth and i can blow thru it with no problem so i will replace that and the prv and see if it works.

 

if you are having the same problems just replace the t-valve and prv valve... now the car runs great... here are the part numbers t-valve 06a103245f and the prv-06a129101c

 

I think I have a problem with the T-valve (bleeder valve) on my B7 too.
Does anybody know where it is located and how to get to it?