RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

Took the RS4 up to Charlie at Surrey Rolling Road on Saturday (highly recommended by the way). I have had the car 3 months now and have had my suspicions that it was a little down on power and wanted to get it checked.

I was a little disappointed at the 357bhp recorded, although for a 2007 car with 60k miles and no record of ever having a de coke it is probably not too surprising.

So now it is a case of booking it in to have all those nasty carbons removed and try and get it breathing a little better. Once done, I will get it back on the dyno and post the results.


http://forum.rs246.com/gallery/image_pa ... ge_id=1198

I suspect you may have a vacuum leak to cause that level of power loss - didn't think you usually lost that much through carbon build up alone (can of worms here!!).

Get it up to mrc who'll be able to diagnose what's going on.

Dave

Mine made similar power on mrc rollers pre carbon clean up and 409 afterwards, so not unusual
It'll feel like a new car afterwards with all that extra power

Its more than carbon for those losses,do you still get the 'kick' @ 5500rpm in the higher gears?

lengster1 wrote:Its more than carbon for those losses,do you still get the 'kick' @ 5500rpm in the higher gears?

Mine was 356 from memory and was still giving a kick at 5500. MRC said it was just carbon, but really bad.
It might be something altogether different, who knows

No one's mentioned the 3k-8k test for a while. It's a quick and reliable test to spot cars significantly down on power, originally suggested by ArthurPE. Handy for those of us how can't be arsed putting their cars on dynos.

Search his posts for a wealth of info on the subject or have a look at this link: http://forum.rs246.com/viewtopic.php?f= ... hilit=2+8k

It would be interesting to read a few 3-8k runs before and after these improvements.

The car still kicks at 5500 just not as significant as it should be, it's booked in Thursday to be checked for any vacuum leaks and to have a look at the state of any carbon build up.
Will then decide a plan of action. I don't know if I will get a chance to try the 3-8k thing before thursday morning. If I do I will post the results here.

would love to see this car carbon cleaned and dyno'd back at this same place, for consistency and to eliminate the Shop doing the carbon clean from being the same one to write their own report card.

like what we did 3.5 years ago?

http://www.mrctuning.com/index.php?opti ... &Itemid=18

Well the initial diagnosis is in... There are more carbon deposits than you can wave a stick at. Fortunately after investigation there are no vacuum leaks in the system nor error codes from Vag Com. I am going up to the indy this afternoon to view it myself and will take some pics. The plan is to remove all those pesky little carbons including replacing the oil and the plugs.
I did notice yesterday that the limiter was kicking in early at 7k, which according to previous threads on here and audisrs could be due to a vacuum leak but as there is no leak I'm hoping this is in response to the badly coked engine.

Should have the car back by the weekend and have asked the indy to take pics of the process. I will book the car back on the rolling road asap to get a before and after comparison.

Fingers crossed.

hard limiter or just not wanting to rev past 7k?

Mind too was hitting the limiter at 7000 even after decoke and deflap
Are you running standard exhaust ?
If you are make sure the vacuum pipes are connected to the silencers and listen out for any rattling from the silencer flaps.
Sure sign if vac leak somewhere.
Or make sure the lines which should be connected are plugged sufficiently.
It could be the vac solenoid under the air box you can isolate this by disconnecting the vac pipe straight connector by the right side of the radiator - plug the pipe heading back to the manifold - do this and see if it makes any difference to the kick - if there is no difference the solenoid is fubar
Mine had a cracked casing

It was the hard limiter and yes I am running a standard exhaust. Thanks Roy, will check the points you have raised.

Doug_S2 wrote:like what we did 3.5 years ago?

http://www.mrctuning.com/index.php?opti ... &Itemid=18

Linky no worky. MySQL issue, I'd guess FW or DNS is culprit... (or the link is incorrect).

Well just picked the car up and wow, what a difference, so much smoother and stronger, revs strongly all the way to over 8k.
No vacuum leaks detected, just 6 years worth of carbon deposits which have now been removed, also had new plugs, oil change and air filter.

Will get it back on the rolling road next week and post the results.

Just to confirm the rolling road and indy are completely seperate and independent of each other.