RS6 C5 New Onwer FON - Car gone into Limp Mode

[Imola_Sid]

Hope it's not the same issue as mine.

The only thing i remember about mine was it sounded slightly louder when idling (maybe it was me just being a bit paranoid and imagining it).

But my car drove perfect, just no boost.

Probably worth speaking to Doug as he diagnosed it, so i'm sure he can shed some light on this.

Have you tried all the usual stuff, n75 etc... I went through all of that but had no luck obviously.

Here's what Doug said about mine:

Sid, I'll post what I posted on the other site to see if we can get a more interesting dialog going here:

I am trying to get my head around the symptoms. What is bizarre is that there is no boost at all, not a jot. You'd think that some boost would register before it started blowing air out of the other MAF.

I'm sure that MRC is right, but I have seen cars with a bad turbo making half boost. So why is yours not showing any boost at all.

And why does the 2nd MAF drop to zero on overrun or when the throttle closes? That's what I can't figure out.

This is really common on the RS6. If one turbo does not spin at all - either broken shaft or a manifold collapsed and stuck in the hotside, then only one side spins - but the easiest path for that flow of air is not into the manifold but out the other side of the bipipe - through the dead turbo and flow out the intake side. That is why when not on boost and on engine sucking you get air flow on both banks but as soon as one side that works spins up, that side airflow increases but the opposite side goes from 20-30g/s down to 0 as the air is flowing backwards over the maf. Now you get zero boost on vagcom - nothing significant registers at all. You do need to pressure test to make sure there is not a massive leak (which can also cause really low boost)

Thread is here:

http://forum.rs246.com/viewtopic.php?f= ... 9&start=30

Good luck with it dude!