I have a 98 b5 a4 1.8tqm and i am really having a lot of trouble. The car has 95 k on it and was well took care of but i think that my turbo is out or something...It didnt feel like it was boosting when i bought it, so I bought a new diverter valve for it and nothing. Then i just thought it was under powered, so i bought the giac 1bar ecu, and a boost gauge, and it is still running like 2psi....i dont know what to do now..i even changed the n75 valve and nothing changed. I also took the boot off of the turbo to see for shaft play and there is none, so i really dont know what to do now...i am going to buy a new turbo, but wanted to know what you all thought was the problem? Im running only 2psi, instead of about 14.7, so please some one tell me what might this be. thanks

 

it may be a good sized vacum leak check that out i had the hose on the "pancake valve" rip on me once it ripped on the bottom so it was hard to see and it made my car boost at like 5psi changed that hose and back up to 18psi we went

 

WHere is the panckae valve? and why wouldnt i be running any boost at all?

 

usually when the turbo goes, there is a lot of noise, and also shaft play that you already checked for.

Are you getting any codes?

definitely get the codes read, and look for leaks. Bad hoses are common sources of problems on these.

 

there is no shaft play, and there is no codes being thrown.....maybe the exhaust side bad, or the wastegate?

 

the pancake valve is in the turbo inlet hose on the right pretty much in plan veiw

 

Sounds like a bad DV, or a hose falling apart somewhere.

Check the hose that goes from the front of the intake down to the turbo. Its hard to get to, but its a common point of failure.

 

I just put a new dv valve on it.......maybe i could get a new pancake valve, but when i pulled off the intake tube to the turbo there was no shaft play. i dont really know what else to look at now.....

 

i wouldn't just go out and get a new pancake valve check the hose also check you turbo inlet hose i wish i had a picture of where the pancake valve is im not sure what the valve is really called.

 

round flat valve just off of the turbo inlet? does that have a diafram?