I have a 2000 1.8t quattro a4, I have replaced the maf, turbo, n75, camshaft position sensor and I am still having issues. The problem I'm having is the car will start to build boost.. (you hear the turbo spooling up and can feel the boost) and it will randomly like loose pressure or something and spool down then spool back up and continue this repeatedly until the throttle is let off. I ran vag com and I am pulling the following codes... please help!

VCDS-Lite Version: Release 1.0
Monday, 13 September 2010, 12:46:36.


Chassis Type: 8D - Audi A4 B5
Scan: 01,02,03,08,15,16,17,25,35,37,45,55,56,57,67,75,76 ,77

-------------------------------------------------------------------------------
Address 01: Engine Labels: Redir Fail!
Controller: 4B0 906 018 Q
Component: 1.8L R4/5VT G 0006
Coding: 07251
Shop #: WSC 06335
8 Faults Found:
18098 - Malfunction Indication Light (K83): Electrical Malfunction
P1690 - 35-00 - -
16725 - Shareware Version. To Decode all DTCs
P0341 - 35-00 - Please Register/Activate
18014 - Shareware Version. To Decode all DTCs
P1606 - 35-00 - Please Register/Activate
17963 - Charge Pressure: Maximum Limit Exceeded
P1555 - 35-10 - - - Intermittent
17834 - Evap Purge Valve N80 Open Circuit
P1426 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
17956 - Boost Pressure Regulation Valve (N75): Open Circuit
P1548 - 35-10 - - - Intermittent
Readiness: 0010 0001

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01V-927-156.LBL
Controller: 8D0 927 156 AP
Component: AG5 01V 1.8l5VT USA 3132
Coding: 00002
Shop #: WSC 06335
No fault code found.

 

btw I do not have a boost gauge

 

Why don't you decode the fault codes to save us having do the work.

http://www.bentleypublishers.com/tec....dtc.table.htm

 

I have a 2000 1.8t quattro a4, I have replaced the maf, turbo, n75, camshaft position sensor and I am still having issues. The problem I'm having is the car will start to build boost.. (you hear the turbo spooling up and can feel the boost) and it will randomly like loose pressure or something and spool down then spool back up and continue this repeatedly until the throttle is let off. I ran vag com and I am pulling the following codes... please help!

VCDS-Lite Version: Release 1.0
Monday, 13 September 2010, 12:46:36.


Chassis Type: 8D - Audi A4 B5
Scan: 01,02,03,08,15,16,17,25,35,37,45,55,56,57,67,75,76 ,77

-------------------------------------------------------------------------------
Address 01: Engine Labels: Redir Fail!
Controller: 4B0 906 018 Q
Component: 1.8L R4/5VT G 0006
Coding: 07251
Shop #: WSC 06335
8 Faults Found:
18098 - Malfunction Indication Light (K83): Electrical Malfunction
P1690 - 35-00 - -
16725 - Camshaft Pos.Sensor Circ Range/Performance
P0341 - 35-00 - Please Register/Activate
18014 - Rough Road Spec Engine Torque ABS-ECU Electrical Malfunction
P1606 - 35-00 - Please Register/Activate
17963 - Charge Pressure: Maximum Limit Exceeded
P1555 - 35-10 - - - Intermittent
17834 - Evap Purge Valve N80 Open Circuit
P1426 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
17956 - Boost Pressure Regulation Valve (N75): Open Circuit
P1548 - 35-10 - - - Intermittent
Readiness: 0010 0001

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01V-927-156.LBL
Controller: 8D0 927 156 AP
Component: AG5 01V 1.8l5VT USA 3132
Coding: 00002
Shop #: WSC 06335
No fault code found.

 

Well you most likely have a bad wire in the N75 harness, this is causing the car to over boost and when that happens the ECU actually closes the throttle. This can even be seen with the Vagcom on the block that shows throttle body %.

 

10-4 I am very unfamiliar with vagcom and I only have the free version, is there still a way to check this without having the full paid version? could i possibly manually test the wire with a volts/ ohm meter? also on a side note i noticed my n249 makes a repeated loud ticking noise, is this normal?

 

You should be able to if you look at block 003.

 

what am i checking for in block 003? sorry for my stupidity

 

The throttle position % and to see if the ECU is actually closing the throttle. If it says anything less then 100% when you are at WOT then the TB is being forced closed.