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JCKustoms
01-27-2013, 10:40 AM
I've searched and found lots of info regarding no boost or low boost issues, but I haven't really found what I'm looking for...

I purchased an '01 A4 quattro with 119k miles about 3 weeks ago and it had no issues when i first got it. Also, the previous owner
said he had the turbo replaced a few weeks prior. After about a week the cel came on so I scanned it with my VAG and it came up
with the secondary air injection pump code, got that fixed (crack hose). Soon after that I noticed there was a severe loss of power...
couldn't even pull out it front of anyone, and with the pedal floored it took forever to get to 55 mph...and no cel or codes...??? So I did
a boost leak check and all good, vacuum check is good (18 at idle). I do not have a boost gauge (ordered one from AWE and should
have it wednesday). I checked the N75 by disconnecting the wastegate line... and no luck... still a dog with no power...???
From the day I test drove it, it has had a high pitch whine that gets louder and faster as the engine revs. I just thought it was the
secondary air pump, but when I disconnected the wastegate line and drove it the whine went away completely (sounded normal)
hooked it back up and it whines again. I checked the wastegate manually and it works... I just can't figure out why I have no power!
Do I need another turbo, or ???

Any help would be greatly appreciated! Thanks

redline380
01-27-2013, 10:44 AM
get the boost guage in and report back, but sounds like a wastegate issue to me if theres no codes/limp mode. if you pull the wastegate line it should overboost, throwing it into limp mode anyways.

how did you check the wastegate? if your grab the rod you shouldnt be able to move it. if you put pressurized air to the line, how much pressure did it take to open the wastegate?

JCKustoms
01-27-2013, 10:57 AM
It definitely did not overboost when I pulled the wastegate line. I did just grab the wastegate rod and it moved freely...???
How will I know if I'm in limp mode?

edit: when I moved the wastegate rod it moved aft, towards the rear of the car. It is all the way forward, towards the front or car when not touching it.

redline380
01-27-2013, 11:06 AM
It definitely did not overboost when I pulled the wastegate line. I did just grab the wastegate rod and it moved freely...???
How will I know if I'm in limp mode?

edit: when I moved the wastegate rod it moved aft, towards the rear of the car. It is all the way forward, towards the front or car when not touching it.

if you can move the rod with your bare hand like that than it either need to be adjusted something fierece or the wastegate acuator is bad

redline380
01-27-2013, 11:12 AM
i'll try to explain it. there is a hole in the turbine housing that lets exhaust bypass the turbine and go straight out of the exhuast. this would be bad while the turbo is attempting to spool, because it will waste all them good exhaust gases. there is a flapper covering that hole that is connected to the wastegate acuator by a rod. the forces on the flapper by the exhaust gases are pretty substantial, so the acuator needs to be quite stout to hold up to the pressure that is force of the exhuast gases inside the turbine housing. im terrible at explaining stuff, but basically im saying if you can move the rod freely, that flapper is easily going to open thereby allowong all your spooling capabilities out the exhaust.

JCKustoms
01-27-2013, 11:42 AM
Makes sense! Thanks. I'll pull the turbo and see what's wrong.

QuattroGinger
01-28-2013, 03:51 AM
my waste just was bad and i could move the acuator back and forth with some resistance whether or not i plugged wasgate hole up front. it was deff bad, cost extremely low boost, couldnt even break 5-6lbs on ko3s. replaced and it was good. i also recently broke hose on my secondary air up front by core cupport and it sequels really loud while it runs, then fine when it cuts off.

does yours sequel the whole time?

JCKustoms
01-28-2013, 08:08 PM
Well it turns out that the whine was coming from the turbo. The nut on the fresh air side of the turbo shaft came off and was wearing against the blade. Ordered a new turbo today! Hope to get it in on Thursday...

redline380
01-28-2013, 08:16 PM
I'm going out on a limb here but I'm guessing that's your problem....
on a serious more you may want to check the intake tract for turbo material

JCKustoms
02-03-2013, 10:30 PM
Installed new turbo, cleaned up intake tubes, and now it runs awesome!
Thanks for the info and help!