Power loss at higher revs

[Mancmatt]

Hey guys.

I've a strange issue and wondered if anyone knows what may be wrong.

My RS6 seems to have lost power at around 4500rpm. Kickdown seems fine and car shoots up to a certain point then boom - the last 2000RPM or so it feels dead - like an old diesel! It's almost as if it drops into top gear when it shouldn't but I don't think this is happening as the issue remains in paddle mode.

Do the turbo's kick in sequentially? Have i lost one of them perhaps? My missus drives the car mostly so it's very rarely run at high revs - she hadn't even noticed the issue!!

Any suggestions appreciated. Cheers.

[Shoppinit]

It is time to buy that most useful of RS6 tools... a vagcom.

Start by checking:

MAFs
N75
DVs
Intercoolers

You didn't put 95 octane in, did you?

[RS6Steve]

As he said. The best £300 you will spend for a 6.

Mine saves me a fortune or cost me a fortune as I now know exactly whats going on with it.

[Rupert]

The turbos are not sequential, there is one for each half of the engine.

Mine had a problem where the acceleration would tail off towards the red line, in fact it would take (what seemed like) an age to get there.
The lower revs were OK at the start of this problem, it would have more torque when it changed into 3rd gear than it had at the top of 2nd gear.
It wasn't long before the emissions light came on, and the idle revs were high, so it would happily pull along at 30-40mph at idle speed.

In my case it was the O2 sensors in the exhaust.

[Shoppinit]

Engine out job?

Friend of mine managed to change his rear lambda sensors without dropping the engine. FYI Don't think the 2nd sensors have any effect on engine power though, just there to check the health of the cat.

[Doug_S2]

You can change any egt or lambda and get the orignal clips for the lines back on without removing the engine.

I am sure vagcom will show a lambda or egt, or you have a one way valve gone or hose split

[Rupert]

Engine out job?

Friend of mine managed to change his rear lambda sensors without dropping the engine. FYI Don't think the 2nd sensors have any effect on engine power though, just there to check the health of the cat.

According to the book yes, but they can be changed with small hands and grazed knuckles.
Apparently they were contaminated because of faulty coil packs (one on each bank).

[Mancmatt]

The turbos are not sequential, there is one for each half of the engine.

Mine had a problem where the acceleration would tail off towards the red line, in fact it would take (what seemed like) an age to get there.
The lower revs were OK at the start of this problem........In my case it was the O2 sensors in the exhaust.

This is exactly what mine is doing! Hopefully it is something this simple.

I will invest in the Vagcom soon. Short term though, I'm due a service so will book it in with Grizz and let him take a look while he has it. Praying that it's not an engine out job!

Thanks for feedback guys.

[chunky79]

Where in the midlands are you mate? I have Vagcom and can whack it on your motor if you want. I don't know what the hell to do with it but can try and help

dunc

[grizz]

We don't remove the engine for egt's or lambdas ..

[Mancmatt]

OK. Thanks grizz. Will call you to book. Hopefully you have an angle grinder to stop it shredding tyres too? ATS won't do it!