S3 boost issues

danny_dj3

danny_dj3

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Hi all, new to the forums and looking for a little help;

Bought a 2001 amk s3 just before xmas as a treat for myself, however there are a few issues that have popped up and to be honest, I have searched the pages here for hours trying to find answers with respect to boost issues/ leaks.
The problem is when I set off, I have good boost in 1st gear, then as soon as i grab 2nd its as if the boost has simply died, then reapears in 3rd and goes like a train to about 4500 rpm where it feels like boost is dropping again. After various youtube vids and searching the forums, i put it down to the n75 which i swapped out for a new one this afternoon, however after a quick run about the its still not right. So i read a bit more here, and a lot of peaple seem quite set that running a dump valve is bad. The car has a remap by AmD and on the recipt it states a forge dump valve was fitted [gonna try and bell em tomorrow and see what map it got] but looking at it, it appears to be a recirc/blow off valve.
All lines seem in good condition, altho no doubt a smoke test would be a good idea.

I'm wondering if i should get a straight divertor like the 007p or if the one thats running is on because of the tune.

I'm also looking for recomendations for a good S3 specialist in the Manchester area :)

sorry if this has been posted prior, just cant get my head around the on/off boost and the more i think on it, the more i think its the dv.

thanks all,

Danny
 
Not sure the DV will cause it to give you your intermittent boost issue, however, it wouldnt hurt to go for a 007p/stock Bosch/GFB DV. If you have one of the SplitR ones, bin it, they're poo and cause all kinds of problems...

Check all your hose clamps are tight, check the hoses are all ok (smoke test would cover the above). One other thing to consider is that in some cases, the TIP has been known to collapse on itself while the turbo is sucking in air, so check on that while you can too.

If none of those things work, get the car scanned/logged with VCDS and use that to figure out exactly what's going on.

I'm running on the assumption that you use V-Power/Tesco Momentum fuel, but if you are just using regular fuel, it could be a contributing factor

Sent from my CLT-L09 using Tapatalk
 
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Yup, thats pretty much what i was thinking about the forge splitter thats currently on, as so many peaple here recommend a standard/007p because its the way the car is supposed to run. I did have the management light come on whilst driving to work so nipped to my mechanic who scanned it , 5 faults were brought up, one of which being for mechanical turbo failure, which i was told could possible be the wastegate not closing properly. Ithink the others were for the alarm, an o2 sensor and some minor stuff
The turbo seems fine, no play nor damage thats visable.

failing actuator maybe? Would that match the symptoms of the boost dropping and not being there for 2nd as the wastegate is still shutting?

been a while since i got into cars, a wife, 4 kids and a business take up most of my time xD
 
Best thing to do would be to first eliminate any boost leaks and investigate any O2 sensor issues if you have them (dont remember if AMK is wide or narrowband - I'm sure smarter people than I will chime in with better info!)

Can possibly use VCDS to log actual vs requested boost but I'm not sure how much information that will yield - I would say first port of call is a smoke test

Sent from my CLT-L09 using Tapatalk
 
The specialist I use in Manchester Is awesome gti or unicorn motorsport in stockport
 
Vcds scan should be your 1st thing to do, if you don’t have it I’m in Manchester if you want it scanning save you paying for it
danny_dj3 said:
cheers for the replies fella's, at least now i have a route to go at it :D
Click to expand...
 
Also just get the oem recirc valve the forge 007p is no better than the standard one
 
check fault codes for why its probably dropping into limp mode.
have you checked codes yet?
VCDS is your friend for S3 ownership
 
Aye, I will try and grab a standard tomorrow if i get chance, TPS / euro i guess.

Tj, thanks for the offer, I know my usual garage has a snap- on diagnostics, not too sure about VCDS tho. [not really up to date on current fault finding equipment] so if you are ok for me to pop down over a weekend, that would be great :)
 
Yeah that’s fine , I’m in burnage
Tps can be a bit funny saying it’s trade only but Trafford seem to be a bit relaxed on it if not audi dealership
 
checked awesome, and they have them in so might hit there on my way out to a job, will post up n let you know how it goes.
 
big thanks to TJ, ran the VCDS :)

4 Faults Found:
17608 - Boost Pressure Control Valve (N249)
P1200 - 35-00 - Mechanical Malfunction
17544 - Fuel Trim: Bank 1 (Add)
P1136 - 35-10 - System too Lean - Intermittent
18010 - Power Supply Terminal 30
P1602 - 35-10 - Voltage too Low - Intermittent
17511 - Oxygen (Lambda) Sensor Heating; B1 S1
P1103 - 35-00 - Performance too Low
Readiness: 0010 0001

so n249 faulty, not the n75 that i replaced.

other issues found seem to be central locking/alarm based.

13 Faults Found:
01367 - Central Locking Pump Run Time Exceeded (Likely Leak)
35-00 - -
01371 - Alarm triggered by Door Contact Switch; Driver's Side
35-00 - -
01372 - Alarm triggered by Door Contact Switch; Rear Passenger Side
35-00 - -
01374 - Alarm triggered by Terminal 15
35-00 - -
01370 - Alarm triggered by Interior Monitoring
35-00 - -
01369 - Alarm triggered by Hood Switch
35-00 - -
01368 - Alarm triggered by Luggage Compartment Switch
35-00 - -
01365 - Lock/Unlock Switch; Interior
29-00 - Short to Ground
00991 - Interior Lights
28-00 - Short to Plus
00955 - Key 1
09-00 - Adaptation Limit Surpassed
01134 - Alarm Horn (H12)
76-00 - Terminal 30 missing
01134 - Alarm Horn (H12)
77-00 - Internal Supply Voltage
01134 - Alarm Horn (H12)
49-00 - No Communications

5 Faults Found:
01377 - Ultra Sonic Sensor for Alarm System; Left (G170)
27-10 - Implausible Signal - Intermittent
01378 - Ultra Sonic Sensor for Alarm System; Right (G171)
27-00 - Implausible Signal
01380 - Alarm triggered by Anti-Theft Sensor; Rear Left
35-00 - -
01381 - Alarm triggered by Anti-Theft Sensor; Rear Right
35-00 - -
01382 - Alarm triggered by Anti-Theft Sensor; Front Left
35-00 - -
 
I doubt the N249 is faulty... That code means the ecu tried to use the N249 to actuate the dump valve and didn't see the boost drop quickly enough...

This pops up when you have a faulty DV, air leak or N249 bypass

<tuffty/>
 
ahh, gotcha. nope, no n249 bypass there, its all stock, the DV is still the forge dump/splitter as as i was late gettin to awesome for a divertor today, but will still swap that out. I have noticed the revs seem to drop quite slowly, might just be im used to diesel engines, but it does feels sorta slow and to be honest, i did wonder about that. I know i have alarm issues, the keyfob does nothing after replacing the batteries, and im a little sketchy on how to recode the key, prob gonna be a dealer fix.
My main concern is just to get it running mechanically right, the rest i have plenty of time to sort.

Would it be an idea to try bypassing the n249 and connect direct from manifold to dv just as a test to see if its messing about, as the management lights back, or just order up a divertor and see how she runs?

gonna defo get it in for a smoke test next week too :p
 
Recoding the keys can be done with vcds as well do you have both the keys ?

just a thought but when my fob wasn’t working and had to use the key you only have a few seconds to turn ignition on or the alarm goes off, they might why you have codes in the alarm
 
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nope only got the one key with it but thats exactly what happens, key in door, drivers side unlocks, jump in alarm flashes but no siren/horn and the key disables the alarm. then the rest of the doors unlock. I did read somewhere on the forums that there is a battery on the alarm horn that can cause this kinda fault when its drained. I also get the alarm beeps from the dash.
auto electrician required i think, I hate messing with the alarm system :D
 
The alarm siren battery leaks and corrodes the pcb, it won’t set the alarm off it just that the siren won’t work they are in the boot on passenger side easy enough to swap once you get to it
 
Tj 0785 said:
Recoding the keys can be done with vcds as well do you have both the keys ?
Click to expand...

Resyncing a key to allow it to open/close on button press can be done without VCDS.... procedure is in the handbook...

VCDS is required to add new keys (to immo) but you need the SKC code to be able to login and do that

<tuffty/>
 
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Cheers tuffty, i had tried previously to re sync it, but it just didnt want to know. Just gone out, followed the rather easy instructions and its worked just fine.
 
I couldn’t get it to work properly on mine would need redoing a few days later
<tuffty/> said:
Resyncing a key to allow it to open/close on button press can be done without VCDS.... procedure is in the handbook...

VCDS is required to add new keys (to immo) but you need the SKC code to be able to login and do that

<tuffty/>
Click to expand...
 
ordered a divertor from awesome today, none in stock so a few days wait on that, going with standard bosch so hopefully by weekend, should have a better idea whats going on. On the plus side, the key is still working so thats good :D
 
Right, quick update;

Been out whilst the weather is nice and got a lot more in depth in the engine bay. checked all the pipes and connections i can and to be fair, all feel soft and still in good condition, i did make a point of looking for the factory clamps and double checking those lines. TJ mentioned to me about any oil on the pipes, so after another check, there seems to be a light mist on the pcv pipe back to the tip, and a small amount of clean oil externally on the very bottom of the tip/turbo.
After running properly thro the forum, i found a post about the pcv valve possibly effecting the boost, so ordered another from Audi.

I think i found the problem, after checking pics i took of the engine [for reference reasons :) ] i saw a vid of someone working on an engine and their dumpvalve was the opposite way around to the one i took off, and with a little more digging, found another post explaining the right way it should be fitted. Swapped it around, took it for a drive and it feels a lot smoother and now seems to boost waay less aggresivley. it seems i have basically copied someone elses mistake unknowingly.
 
audi upgrades
Do some data logging and post the logs up - will shed more light on what's happening

Sent from my CLT-L09 using Tapatalk
 
Hi all, cheers for all the advice and help, got the car sorted today. Turns out that the previous person to work on the car [owner/mech, dont care either way] had fitted the n75 incorrectly.
I have been going thro all the old posts, and after seeing a pic of an engine bay, thought mine didn't seem quite right, so checked with the pics i took before swapping the original 'failed' n75 for the new one. It was wrong. [ newbie to the 1.8t 's]
Swapped the pipes over, let her warm up and went for a nice little blast over Saddleworth tops and I'm still smiling :D
Fast, smooth and very responsive on the throttle now, its a different car all together.

As this has all been plumbed together, im assuming theres been stress thrown at the turbo, and to be honest, i have no issues replacing the CHRA [done it previously] but other than that, should i be looking for any other faults that could arise [ a little paranoid now ]

Once again, cheers all for the help :)

danny.
 
So, rather than start a new thread up, I thought i would just post updates with the car here as i go along.

So today, i decided to fit the pipes off TJ, and decided it might be better to do this at home rather than at the unit, which was a good call. I had noticed oil around the pipework under the manifold, and after a little poking about decided remove what i could to check for leaks, and straight away the lower crank elbow fell apart at the T section. Good call on doing it on the drive :)
also found a small hole in the vac line from under the manifold to the fuel rail, so nipped that back and made good.

ordered up new elbow and check valve from tps [ as the valve looks pretty dirty ] and should be fitting on weds morning so fingers crossed thats the last of the oilly mess i will be seeing from there for the near future lol.

kinda looking forward to getting this running right.

also, how often do peaple check their 'puck' valves?, as one i looked at today had pretty much sucked the diaphram into the out side and totally blocked it off.
 
Im in the process of swapping the bean can some one fitted to mine , in the past, no idea how old it is , or if its good bad or broken , the system however passes a 'leak test' at low pressure ... hopefully its the cause of the 'noise' associated with any boost pressure and the odd 'clucking sound' on lift off ... Word from the 'Sett is, just fit a OEM device ,
 
yup, oem is the way im going with the older parts.

I still have a few niggles, but hopefully tomorrow once i get it put back together, it will run better. Its felt nice to drive, however seems to have a complete flat spot once its started to boost, from 2800k-5500k is just a gradual pace, and from the few vids of stage 1 amk's i have seen, mine is not the same.

It still throws traction light on when moving off at slow speeds, not all the time but enought to cause an issue if i have to pull away quickly, no fault codes for this. once the cars warm, it doesnt seem to do it as much, if at all. possibly a sensor?

the other things thats bugging me, which everyone says is the clutch switch, is that once the cars warm and im sat in neutral, if i give it a little pedal, the revs will rise and hold for a few seconds, however im wondering if its also down to the broken breather pipe as it has been sucking a lot of oil into the intake and over the last week or so, seems to have lost about 1/2 a litre of oil. it does look like most of thats on the front of the engine tho :) guess i will know better tomorrow.

Its booked in for a full checkover at a mates garage next week anyways so no doubt i will be asking daft questions again soon ;)
 
There's no daft questions mate that's what we are all here for.
You seem to be having a few niggles to get sorted.
I did away with my pick when I got a catch can fitted and vented to atmosphere then blocked the tip where the puck would have went to. If you dont have a catch can maybe think of that.
Also if you do the n249 delete then that takes a lot of hoses away that causes leaks that are on top of the rocker cover.
There is guides in the FAQ on how to do both.
 
well, i stuck the new elbow and the check valve, had to use the original pipework as im missing a hose and took it for a spin.
It feels smoother for sure, and defo quieter, but before that, i noticed that the elbows on the 'carbon catcher'?? next to the header tank seems to have 2 loose fitting, i would upload pics but they are too big. This is something i haven't yet looked into so it might be normal.

been thinking about a catch can tbh, as im really starting to hate the amount of seemingly endless pipes and lines that have the potential to go belly up due to the age of the car, to be expected i know, but im starting to question what can be removed without causing issues.

gonna stop looking under the bonnet till next week after my mech has give it the in depth once over, im starting to get paranoid due to seeing a nice little puddle of what looks like fresh oil on the top of the gearbox next to the block. ha! might be buying a engine stand earlier than i anticipated xD
 
Yup ... every time you fix something , its 50% better , than it was before ... )
 
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They do say buying a s3 is the cheap part keeping it running the expensive bit
 
lol

heres the bits im not sure about and the beautifully blocked puck. [ not mine btw ]
Loose bits
Problem


erk, soz about pic size
 
ok, so today i got bored and wanted to get the whole 'whys it not running boost thro the rev range' issue narrowed down a bit, so i did a pcv delete.
went all over trying to find the 19mm pipework, but after trying a few local car shops came up blank [ prob euro parts have some ] so i decided to do a quick bodge job just to see if the system was the culprit.
used the pipes i got off TJ, blanked off the T on the bottom of the crank-puck pipe, blanked off the nipple in the middle of the intake manifold and directly connected the brake booster to the end of the intake.
warmed the car up, took a quick drive to the shop for some well deserved beers [ hard week ] and was quite suprised when the car seemed to keep boost up to about 5k rpm :D

now im not 100% good with this, as a little drive doesnt really give me a good idea of how its running, but for the most part it feels and sounds much more like a tuned car.

tommorrow im gonna delete the n249 mess, leaving the main body of it connected electrically and hide that away neatly.

after trolling thro the audi group parts page, i still cant find what the first pic is in the above post. i know its fuel related but if i google pump/filter etc nothing comes up right

more nooby questions. what is it and should 2 of the 3 fittings be wiggly loose?

i'm seeing a fair few puffs of smoke now from the backend, and im concerned the n75 being plumbed in incorrectly could have
damaged the turbo seal, i have had a quick feel down the pipe [ lol ] and there seems to be a little oil, clean, at the bottom. i still
havent got my hands down there to remove the tip and check for play on the shaft, as im not the smallest guy and im gonna
need to remove a few bits before i can get in there.
if its ******'ed then as far as im aware, i need to get a standard CHRA and not a hybrid [read the post on that ;) ] prob from
Bill. this leads me to assume [ assumption is the mother of all f*** ups ] that im running a k04 023? am i right with this?
also been told it could just be oil seals due to the age of the car.



getting a little excited for mondays trip to the garage to actually get under this for the first time properly and see how much more im gonna have to work to keep the smile on my face !!
 
That picture you are talking about I think it's either called a carbon canister or charcoal canister. It a evape for the fuel fumes so no smell of fuel I believe. I wouldn't think it's normal for them to be loose it's not something I've looked at on mine but I think it should be a tight fit.
 
yup, thats why im asking, i do occasionally get a slight whiff of fuel from the front end, tho pretty rarely tbh, that would explain if theres loose connections there. no visable or traceable leaks anywhere else to my knowledge. if thats the charcoal canister, then whats in front of the header? i remember someone saying a return for unused fuel, todays the first time i have heard it clicking if it is.
 
Im not sure where you are talking about but that canister sits in front of the coolant bottle and behind the washer fuild bootle.
There is also a over run pump that makes a noise when u stop the engine that sits beside the drivers headlight.
 
took the car for a longer drive today and its much better. popped down the the garage to have a mate take a look at it and its all looking good. the fittings i was concerned about are the fuel lines and are fine, me being paranoid.

still booked in for a full checkup on monday, but feeling better about it :)

any recomendations on a catch can kit would be appreciated as i have been advised its prob the right way to go with the older engines. looked thro the guides and its an easy fit.
 
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