Ooops what does this mean.. hope it's not bad!?

[BrilliantBlack]

Took the 99.5 S4 out for a fun drive on some good straight roads nr me and noticed something that I got that instant feeling about.. always at exactly 3400rpm in 3rd and 4th gear the car seems to hesitate a little.. and then boosts back to life with a little kick.. what i can describe as a very small flat spot.. it's not dramatic.. just enough to notice..

On first inspection I noticed that on the air box, the far right/bottom clip hadn't been clipped back on.. in the end I had to take the entire air box out (cause I'm a weed and couldn't clip it back on by hand).. took the car out for a spin after completing a "reversal of removal" and it's not as noticable.. so I'm convinced it's "air" related... but don't let me mislead u experts out there..

Its got a "superchip" remap on the ECU if this is any help.

Doesn't do it in 1st, 2nd or 6th no matter how easy/hard boost i push..

Plus another note, how well do your cars idle. My 2000 1.8TQS is so steady at idle i sometimes to check if its still running. It doesn't waver AT ALL.. but the S4 has little blips at idle.. is this normal.

Sorry for numerous questions.

Thx all..

Nige

[ChipHazzard]

Evening Nige

I would suggest getting a VAG-Com scan done to see if any DTC's are apparent, I'm sure there's some body near you that could help if you dont have it yourself.

Failing that I'm sure one of the more learned members on here will be able to assist / offer more advice

Cheers

Mike

[s4woody]

well my clip was off for months so i dnt think thats anything to worry about..they have an air intake at the slam panel so the airbox aint a sealed unit or pressurized..
as for idle mine fluctuates sometimes but i just ignore it..as long as you have no boost related air leaks then it shud be fine..
but like chip say,s if your worried find a member near u with vag-com and just check for any fault codes..

[jfeb]

I don't know about the airbox or flat-spot but my 99.5 S4 also has a pretty uneven idle - so much so that Minhea at MRC commented on it. I haven't done anything about it though.

[jimbogrey]

are you sre that's 3400 and not 4300 as at that point its something to do with the timing changing and is most noticeable in 3rd, but I'm no mechanic just something i was told .

jimbo

[MarkB]

are you sre that's 3400 and not 4300 as at that point its something to do with the timing changing and is most noticeable in 3rd, but I'm no mechanic just something i was told .

jimbo

Camshaft timing changing?

[dr_wimpkins]

My idle is smooth as can be at about 800RPM, but then again, it is a standard beast.

[BrilliantBlack]

Might have something to do with the missus...

She so kindly put a tank full of 95 RON from flippin Tesco and not mentioned it..

I thought I'd never noticed it laggin before; it must just not be running the same with 95 RON and it being chipped.

Is a panel air filter worth fitting? e.g. Green/RamAir/K&N?

Nige

[SimonS4MTM]

Stick with the OEM filter

[BrilliantBlack]

Anyone else share Simons view with OEM filter?

Why's that Simon?

[oliew]

id say stick with standard too... the rest dont really provide any better airflow and the paper ones dont need oiling which is known to kill the MAF (mass air flow) reader

[SimonS4MTM]

No flow gains to be had with changing it.

I believe that there are some mods you can do with the airbox, but I am sure someone else will be along to advice on that one.

[Jez]

There is a 'sportec' mod you can do to the airbox, which is basically cutting a whole in the front of the box. I din't notice much difference other tha slightly more induction noise.

As for filters... as far as I am aware this is not a restrictive part even when at stage 1 (remap). In fact I have yet to see valid claims that an after market filter flows more than a clean OEM filter!

[CliveH]

Nige,

I would suggest that you get your car to reputable tuner for a full health check, but in the meantime certainly run Vagcom on it with someone who can interpret the results for you - or post them on here.

[s4-99]

Anyone else share Simons view with OEM filter?

Why's that Simon?

I have had my K&N induction kit fitted for about 18 months now. I've had no problems and it sounds nice....I'm not sure it gave me any more horses but i felt improved throtle response. You just have to be carefull not to over oil it when you give it a clean. I haven't had to change any Maf's because of it. I must admit, i haven't come across anyone else yet who has one fitted.