Serious hiccups at 5500rm, any hint ?

[Taipan]

Hello everybody,

I have a persistent issue with the RS4 when the code is turned on (ie not in 380hp setup).

Here's what happens :

- in 4th, 5th and 6th gear, I have serious hiccups around 5500 rpm and above. The whole car starts shaking back and forth.

- I had a VAG-Com log done and it shows Pinging/Knocking and Timing <beep> as high as 8 degrees BTDC (Before Top Dead Center) in the higher gears.

- The Turbo (or so it seems) make a very strong and irregular whistle sound, all the time (from 3000rpm and beyond).

Any hint ?

Eric

[johneroberts]

Yeah Eric..... get a MTM Chip [img]images/graemlins/grin.gif[/img]
Cheers
jr

[Taipan]

Hehe.. Sir Charlie Big Potatoes [img]images/graemlins/FIREdevil.gif[/img]

The thing is I've been in a few RS4's with the SAME code and they don't suffer the same prob.

The other thing is I "heard" Kim Collins had a similar issue with an MTM 458hp RS4 and hadn't find a solution yet.

Thus my candid question putting the code aside.

Eric
PS : although there are examples of highly expensive failures with MTM tuning and difficulties in implementing 460+ upgrades, if I go down that path, that may not be for just 460hp [img]images/graemlins/wink.gif[/img]

[Nordschleife]

Eric
It sounds as if you have two issues,

failing turbo(s)
the after effects of a bad tank of fuel

I am resigned to failing turbos (100% failure rate) and I know that bad fuel really upsets tuned engines.

Incidentally, I would pick a tuner who gets on with Audi, that way, when your turbos fail, you will get them covered by Audi or the tuner (or both), will Revo pick up your turbo bill?

Sorry to hear about your problem
Robin

[DuncS3]

Eric,

Dont know if the RS code is so different to the S3, but on the S3 you should not be getting <beep> of more than about 3-4% without something being wrong. Do you have a SPS3 device? Have you advanced the timing recently?

The other thing that could be the culprit is your MAF. The MAF has to work more in chipped mode (hence okay in stock), and if the MAF is faulty, it could be upsetting your mixture, causing the car to knock. Ben Bjacks had a faulty MAF on his S£, caused the same result (regarding knock).

Also a 'faulty' MAF will not register a fault code on VAG-COM.

On the S3 around 190-200 g/s is a good value in chipped mode to indicate its working, but for the RS I have no idea. Contact REVO mate...

Dunc [img]images/graemlins/s3addict.gif[/img]

[TimJMS]

Hope you are well Eric. Long time no post!

Sorry to hear the problem still has not gone away.

I wonder if your unique exhaust system is causing a problem. If you are planning a radical future modification, then perhaps its time for the downpipes on the Milltek now to remove this restriction?

After all, there is very little to be gained by cleaning the drains, if you never take the plug out of the bath!

Cheers

[rs4steve]

normally find a glass of water does the trick for me [img]images/graemlins/bigwave.gif[/img]

eric on a serious note sounds like a faulty sparkplug

c u later steve [img]images/graemlins/tung2.gif[/img]

[Taipan]

Hi guys,

Thanks for the fast feedback, i'll try and answer all points/questions.

- Bad tank of fuel : I only use 98 premium fuel from majors like BP/Total/Shell. Also it does it all the time since I get the upgrade (made about 20 tanks since then). Keeps doing it.

- Code : I SERIOUSLY exit the code as the cause because (1) i've tried several codes and it always did it and (2) I've been into RS4s with identical/similar codes and felt nothing like that. I may also test an MTM 458hp code but from what I gathered, the weakness is most likely in the engine components per se, thus a different code won't make any difference.

- SPS3 settings : I've tried different settings, from low boost to high boost, standard to low to high timing, and also did a full reset of car (unplug battery). Keeps doing it.

- Exhaust : whichever exhausts I had (standard Milltek one, Special Track one -no intermediate silencer- and now full Milltek with Sport Cats/Downpipes), it keeps doing it.

- Fuel Pressure regulator : was upgraded from 4bar to 5bar (thanks for that, u guys know who u are). Keeps doing it.

- DV's : I upgraded from standard DV's to Forge DV007P with green springs. Keeps doing it. Upgraded to red springs (thanks again, guys). Keeps doing it.

- Failing turbos: never investigated that. How do u check failing turbos ?

- MAF : never investigated it. I may replace it "per principle".

- Faulty sparkplug : never investigated it. Any brand/model recommended ?

- Vag-Com logs : I can post two of them if anyone masters these.

Eric

[Nige_RS4]

Eric, did you see any fault codes in the 'engine' module when you checked with vag-com ? Send Andiroo a PM ref. typical MAF g/s settings for a modified RS4 before you replace it - I think they max out at 355 g/s or something near that ?? Doesn't sound like a boost leak, but worth putting a boost guage on to see what the boost is doing (might be going into limp mode or something?)

Hope you get it sorted m8

Nige [img]images/graemlins/thumbs.gif[/img]

[rs4steve]

forget the b*llshit definetly sparkplug been running high boost turbo'd cars since my turbo'd pushchair think about it the sparkie is the main essence of combution isaac newtown may not be alive but i am

thanks again blackcuntry nutter steve [img]images/graemlins/jump.gif[/img]

[fade2grey]

Here's a couple of things to try - Millers (or equiv) octaine booster - If that helps the map may be to agressive for your conditions. Also check intake temps as this can also cause knocking etc.

Check your coils & as said further up the thread, your plugs. One of my friends has a similar problem with his skyline at the moment - turns out to be the coil packs being dodgy.

For both of the above you should be able to tell pretty quickly if they are the cause of the problem or rule them out.

A

[Nige_RS4]

forget the b*llshit definetly sparkplug been running high boost turbo'd cars since my turbo'd pushchair think about it the sparkie is the main essence of combution isaac newtown may not be alive but i am

B*llshit doesn't baffle brains theses days Steve - vag-com didn't exist either [img]images/graemlins/tung2.gif[/img]

Eric, does vag-com show detonation on a particular cylinder, if so, it is more likely to be coil-pack, plug related.

Nige [img]images/graemlins/thumbs.gif[/img]

p.s. turbo cars weren't around when you were knee-high to a grass-hopper [img]images/graemlins/033102ass_1_prv.gif[/img]

[Taipan]

Thanks again, guys.

Just a quick one : what is "coil" or "coil packs" ?

Also, on the vag-com : I am a total newbie in the field so I wouldn't know where to look for detonation in a particular cylinder.

I posted the two Vag-Com log files under CSV format so they can either be opened with Excel or with VagScope (for graphical display).

Http://www.rs4-video.com/vagcom

Anyone who can read/detect something weird, please don't hesitate because I'm clueless.
(I think one file also recorded the intake temperature).

Cheers,

Eric

[Joshie]

Thanks again, guys.

Just a quick one : what is "coil" or "coil packs" ?

Eric

In the olden days the charge to the spark plug was supplied by a coil (to generate the charge) and then a distributor to allocate that charge to the relevant spark plug.

Nowadays there isn't a coil or distributor as this has been replaced by coil packs - one for each cylinder. The command to generate the charge comes from the ECU.

[sitas3]

Eric,

just quickly looked through your log files and there is definitely too much knock being detected by the knock sensors at the higher revs (target area is closer to zero as possible in CF columns on measuring blocks 022,023 and 24 with anything over 4 considered to be excess detonation)- this could be because of too much ignition, dodgy ignition circuitry or they are picking up some kind of mechanical noise (probably unlikely as I think these sensors listen for a specific harmonic frequency)

I'm with Steve - first bet is the spark plug(s)/coilpack - maybe buy one and install on each cylinder in turn and do more logging after installation until the dodgy one is found.

Please get in touch with Mitch at REVO about this for more advice. can you put the car back into stock mode, do some more logging and see if this does the same?

best logging method is to start the logging whilst in 4th gear at low RPM and then slam your foot straight down on the gas until 6kish revs

for boost leaks, maybe try logging block 115 and look at requested vs actual pressure