moelharairi

Hello Guys, Please help…..
I have an Audi A6 2.8L ATQ 2000 automatic. Recently the RPM has been fluctuating when I drive in the City between 25MPH to 50MPH. Having my foot steady on the Gas sometimes the RPM drops below 1500 then it goes back up to 2200 by itself. At times, the cars seem sluggish going up hell. And It really takes its time to speedup unless I press my foot hard on the gas. However, over 60MPH seems to be fine.
I recently purchase the car and I am not sure what type of tune-up it had. I am trying to do maintain it without spending that much money on it. I called the dealer they said it might be bad valve I am not sure which one they are taking about.
Things I have done thus far:
Engine Light was on: I changed O2 sensor downstream right, code cleared.
ABS/Break lights are on; put it on the computer no communication. I think the ABS ECU needs to be rebuilt. Not sure if this has something to do with my issue or not.
This is my first Audi and I really would love to keep the car. Please help.

Joby

Check your vacuum lines. I had a '00 A4 2.8 and had a bunch of vacuum leaks. Every time I did service on the car, if I even touched any of the hard, plastic vac lines they would crack.

moelharairi

I did some pocking around and here is what I found.
Check engine light is back on: Autozone got communication error. But they were successful in the past when I changed my O2 sensor.
1) Breather Hose is broken into many Pisces. And it looks like it’s clogged. Should I just change the hose or is there anything else I need to do.


2) Something seems to be disconnected on the passenger side, see the picture for details.


3) There is hose under spark plugs, sorry for the bad image, I am not sure what is it for. Do I need to change it and how.

I hope this will help to pin point the problem. Also, can some send me a link on how to do replace my spark plugs on my Car? I am looking for something in details with images.
Thank you all.

rossej

The vacuum hose you asked about in the picture goes to the combination valve. The combination valve is part of the secondary air injection system which is used to pump oxygen into the exhaust to warm up the catalytic converters faster.

Joby

This is the link for spark plug replacement: https://www.audiworld.com/tech/eng36.shtml

And this is the link for breather tue repair. https://www.audiworld.com/tech/eng79.shtml


You can also browse the tech articles yourself. At the top of the page, at the drop-down menu "Resources"go to "Tech Articles"then click "Engine".

You can get the vacuum line at any part store. I'd replace every vac line I could reach in order to forestall any more vac related codes. Like I said before, every time I did anything engine related on my 2.8 those pesky vacuum lines (the cloth ones and the hard tubes) would break. But don't do like I did. I used factory cloth covered vac tube from the dealer, and now the friend that I sold my 2.8 A4 to is now having to replace them all again.

As far as your brake light/abs light, the abs module fails, then you have to replace the module or send it out for repair. It's unrelated to your performance problem. I've heard of Module Masters on one of the Audi forums, or maybe VWVortex forums. You should do some research on it, they aren't the only game in town.

moelharairi

Thanks for your quick respond. How about the line that goes from the driver side to the passenger side in the first picture. It’s very tiny line that got broken on the passenger side. What do they call it?

Should I be worry about the clogged in Vac hose? Can I clean that?

about the line in the 2nd picture under the spark plugs, what do they call it?

thanks again!!

moelharairi

To Keep guys Updated:
I did breather hose fix as per "Tech Article Breather Hose Repair" by Kris Hansen – the only diff I used a metal clamps

Before installing the hose, I sprayed the Carb cleaner in the gunky line. I heard it is safe to do that. I called 3 AutoZone and I spoke to their manager they said no harm should be done. I'll keep you updated if anything.

The small vacuum line, the tiny line in the picture it turns out to be a hard Vacuum line. I got genric one from autozone about $5.00 and I replaced it.

Car drives a bit better but I still get the fluctuation here and then I'll keep you posted

moelharairi

Here where I am: I changed few more hoses and I still have the same issue. I scanned the Car using VAG-COM and I get the following. Any clue where to take it from here.
Background: I had 2 new flex pipe welded, I am not sure if the Monkey guys f***ed something in there see attached codes and readiness

Please help, I am going nuts trying to figure out why there is loss of power and the Fluctuation

moelharairi

Anyone!! please help!!

2.7Lturbo

look up how to run the tests on your oxygen sensors, cat, and evap.... you can run a systems diagnostic on all three of those parts to make sure they are not broken. what it sounds like is you combi valve may still be having a vac leak problem.


give me a bit and ill pull up my old vw tech school book and tell ya how to do those tests