loss of power...turbo not spooling

**ipop07** · 10-28-2009 05:13 PM

1998 1.8T A4 B5 AEB quattro 5spd
Ok so long story short, I bought the car back in may and the guy who i bought it from said the turbo was rebuilt a month or two before i got it.
starting yesterday i've noticed a significant loss in power. I just went on a drive with it to check things out and realized that instead of hearing the regular turbo whistle i hear a clicking noise.

The noise is not audible at idle or when just cruising but it is when i am accelerating. could someone help troubleshoot this? this is what vag come gave me (i checked for errors hoping it will say something that could help):
VAG-COM Version: Release 409.1-S

Chassis Type: 8D - Audi A4 B5
Scan: 01,02,03,08,15,17,25,35,45,55,56

-------------------------------------------------------------------------------
Address 01: Engine
Controller: 8D0 907 557 P
Component: 1.8L R4/5VT MOTR HS D04
Coding: 06201
Shop #: WSC 06435
1 Fault Found:
17584 - Bank1: O2S (Lambda) Correction Behind Catalyst: Control Limit Reached
P1176 -- 35-00 - -
Readiness: 0000 0000

anyone with some advice or troubleshooting advice please help...If I need to get another turbo I would like to upgrade to ko4 so if someone could tell me what are the things this upgrade would require (only things that are required for it not preferable) ..

Thank you in advance

**h4robkr123** · 10-28-2009 05:17 PM

I'm not sure on the turbo issue but the parts required for the upgrade depend on the year of the car. Giac k04 files are different for the different engines.

**ipop07** · 10-28-2009 05:30 PM

its a 1998 aeb

**97a41.8t** · 10-28-2009 05:31 PM

are you burning oil or coolant? A blown turbo would make a loud drill like noise when you go into boost and most likely will start to leak oil/coolant from inside the CHRA.

Before you go replacing turbo's, do a boost leak test and maybe check your injectors

**ipop07** · 10-28-2009 06:04 PM

it doesnt burn oil nor coolant, but im thinking it might just be a matter of time..
the noise is not so much whining or whistling as it is ticking...would a boost leak do that?

**Altech75** · 10-28-2009 06:56 PM

Something could be up with any one of the mechanics that control your wastegate causing it to open and close causing a clicking noise. I suggest you unplug the N75 valve and take it our for a light cruise, see what happens. Don't run it hard while it's unplugged, bad things could occur.

**ipop07** · 10-30-2009 07:11 AM

i checked the turbo, and the turbo seems fine but it doesn't spool at all....taking it to 3rd mechanic today to see whats going on..

**ipop07** · 10-30-2009 01:54 PM

maybe this will help someone figure it out.

:(

http://www.youtube.com/watch?v=OTv6iP9F_Tc

please I need help figuring out what it is, i went to a mechanic and all i needed was 5 minutes of his time and he was a jerk and brushed me off, he said he knows whats wrong with it but he wants me to leave it there so he can diagnose it, cost min 1 hr $70-100, for a 5 minute if he already knew what was wrong..

i am really short on money and still have to pay 2k by end of november for school, now this came up

**Castor Troy** · 10-30-2009 02:22 PM

sounds to me like a problem with the wastegate actuator on the turbo.

**Seerlah** · 10-30-2009 02:22 PM

As another mentioned, remove the line from the wastegate to the n75 valve and see if you build boost. But don't even attempt this if you don't have a boost gauge. You don't want to build boost past maybe 15psi. You just want to do this to check if the turbo is working.

**ipop07** · 10-30-2009 04:46 PM

alright i will check that.

thank you

**walky_talky20** · 10-30-2009 10:33 PM

If that checks out, I bet you're in limp mode due to that fuel mixture correction code (o2 sensor control limit). What are your fuel trims (measuring block 032)? Have you tried clearing the codes/resetting the ecu to see if the boost comes back, even for just one drive?