I’m at a loose end, please help! S3 8V intermittent rough idle.

Leedavies_S3

Registered User
Hi everyone, long time user of the forum but I’ve finally decided to create an account as I really am at a lose end now.

I have a 2014 Audi S3 8V and it has an intermittent rough idle. The revs just seem to drop away but doesn’t always show on the Rev counter. It sort of stutters and grumbles and the exhaust sort of burbles and then it just stops and goes back to normal.

I took it to a vag specialist I use and they scanned it and diagnosed it as the camshafts over and under advanced, changed them under warranty as I’d only had the car a few months costing a huge amount ( thank god for warranty) had it back and on my way home I booted it and then all of a sudden it stuttered and I was left on the side of the road, took it back thinking they had done something wrong but it was diagnosed as a stuck open injector? New one of them and it was good to go! But that’s a story for another day.

Anyway, I had the car back and after a few days it started again, the weird rough idle that only happens sometimes. I’ve searched all over the forum and there isn’t a single person who seems to of had the same problem as me. I changed the pcv valve as a precaution but still to no avail!

Sorry for the long winded post but someone PLEASE throw some ideas my way! Thanks.
Lee
 

ictus_duplo2

Registered User
My car does not like 95 Ron fuel as it gets a slight stutter that you can feel only at low revs. Its fine on 99.
 

Bayzoo

Glovebox Demon
Can you capture footage and post it on here? I’m no mechanic but without seeing the issue it’s hard to tell.
 

Leedavies_S3

Registered User
Can you capture footage and post it on here? I’m no mechanic but without seeing the issue it’s hard to tell.
That’s a good idea, I’ll try to capture it but sometimes it won’t do it for a few days and others it will do it all the time
 

davc

Registered User
My first thought reading this was the pcv valve, but I see you have already changed it.

I had the same issue on my 8p S3 and a new pcv cured it.

When were the spark plugs last changed(should be every 5 yrs/38k)?

Carbon build up in the inlet valves can also cause a rough idle. This technically shouldn't happen on the 8v as the engines run both port and direct injection, but you never know.

Hope you get to the bottom of it mate as you must be pulling your hair out.
 

Jimbbobw1977

Registered User
We had the issue on our 8P 2.0tsi with rough idling as above, coked up engine full of carbon deposits. Head off job and a clean up. Been okay since.
 

Leedavies_S3

Registered User
Any delayed/unusual starting whilst cranking or misfire for a few seconds on start-up?
Doesn’t seem to be, although I have noticed it cranks a couple times more Than usual on start up now, but nothing I’d worry about if you get me
 

Leedavies_S3

Registered User
Oh
My first thought reading this was the pcv valve, but I see you have already changed it.

I had the same issue on my 8p S3 and a new pcv cured it.

When were the spark plugs last changed(should be every 5 yrs/38k)?

Carbon build up in the inlet valves can also cause a rough idle. This technically shouldn't happen on the 8v as the engines run both port and direct injection, but you never know.

Hope you get to the bottom of it mate as you must be pulling your hair out.
you know what, it was serviced just before I had it I’ll have to check if spark plugs have been done but I should think so, and yes I am really pulling my hair out!
I’ve spent more on this car than I have on any of my other cars but I can’t help but still love it
 

Leedavies_S3

Registered User
Still haven’t managed to get a video due to work but it hasn’t done it this week... so annoying as it’s intermittent!
 
Doesn’t seem to be, although I have noticed it cranks a couple times more Than usual on start up now, but nothing I’d worry about if you get me

Sounds similar to the issues I had with my 2013 1.8. Intermittent, no fault codes recorded, sometimes cranked a bit longer than normal cold or hot, sometimes missing on start-up, rough idle, sometimes worse when the engine was cold.
Main dealers and Audi struggled to find any fault.
They 'updated' the ECU software with a modified version from Audi, no better.
It turned out to be fuel injectors, they cleaned them in an ultrasonic bath, no better. They ended up replacing all the direct and indirect injectors (under warranty) and it was ok after that.
 

Leedavies_S3

Registered User
Sounds similar to the issues I had with my 2013 1.8. Intermittent, no fault codes recorded, sometimes cranked a bit longer than normal cold or hot, sometimes missing on start-up, rough idle, sometimes worse when the engine was cold.
Main dealers and Audi struggled to find any fault.
They 'updated' the ECU software with a modified version from Audi, no better.
It turned out to be fuel injectors, they cleaned them in an ultrasonic bath, no better. They ended up replacing all the direct and indirect injectors (under warranty) and it was ok after that.
I hope it isn’t injectors as I had one fail a while ago and it cost a ****** fortune
 

Leedavies_S3

Registered User
Hi again guys, it’s been a while so I hope you’re still willing to help.

Didn’t manage to get a video as it hasn’t really done it.... until I was driving today giving it some it stuttered slightly and then went back to completely normal.

Got home, plugged in Carista and there it was... a p0011 code pointing towards the n205 valve . Did some googling and it seems everyone that has had a n205 problem has had the same issues as me...

Can anyone tell me where I can locate this valve on my engine? (S3 8V 2014)
Thanks!
 

ASRman

Registered User
Had the exact same issue with mine. In my case new spark plugs completely fixed the issue. Soft misfires at idle are apparently 'normal' on these engines. Try new plugs!
 

Leedavies_S3

Registered User
Had the exact same issue with mine. In my case new spark plugs completely fixed the issue. Soft misfires at idle are apparently 'normal' on these engines. Try new plugs!
It’s had new plugs when they did the camshafts so it’s not that! Thanks though
 

Lewbo

Registered User
Hi did you get the the bottom of this having the same problem with mine?
 

Leedavies_S3

Registered User
Hi did you get the the bottom of this having the same problem with mine?
I THINK it’s down to a dodgy vvt solenoid/n205valve.
Haven’t got round to fixing it yet but should be done by end of next week I hope.
No one anywhere can give me an answer and plugging it in isn’t bringing any direct results up so it’s all down to trial and error now.
 

Lewbo

Registered User
Thanks for the reply, well I can report I have now fixed this problem I replaced both n205 magnet solenoids. Idles perfect now, I also had no clue from VCDS was just a case of working through each thing it could of been. Thanks
 

Leedavies_S3

Registered User
Thanks for the reply, well I can report I have now fixed this problem I replaced both n205 magnet solenoids. Idles perfect now, I also had no clue from VCDS was just a case of working through each thing it could of been. Thanks
Could you explain where on the engine this is for me?? Glad you got yours all sorted. Thanks
 

Hamza_Irfan

Registered User
Hi again guys, it’s been a while so I hope you’re still willing to help.

Didn’t manage to get a video as it hasn’t really done it.... until I was driving today giving it some it stuttered slightly and then went back to completely normal.

Got home, plugged in Carista and there it was... a p0011 code pointing towards the n205 valve . Did some googling and it seems everyone that has had a n205 problem has had the same issues as me...

Can anyone tell me where I can locate this valve on my engine? (S3 8V 2014)
Thanks!

I had this exact same code and symptoms on my s3 8V. Took me months of chasing to get it fixed but in the end took it to a local German engine specialist who diagnosed it down to a faulty inlet cam adjuster. Luckily he had a spare one and only cost me £100. Months of hassle and running around like a headless chicken fixed by someone who actually knew what they were doing in half a day! Hope this helps bud. The fault with the adjuster seemed to trip my ACC and pre sense and stopped it from working at times as well. Been working perfect since the fix (touch wood).
 

Marky79

Registered User
Funnily enough I’m having the exact same problem. Dealer can’t find anything wrong. Yet it’s got the exact same symptoms as the guys above. I think in the new it’ll be going back till it’s sorted. Somethings not right.
 

Hamza_Irfan

Registered User
Funnily enough I’m having the exact same problem. Dealer can’t find anything wrong. Yet it’s got the exact same symptoms as the guys above. I think in the new it’ll be going back till it’s sorted. Somethings not right.

I bought mine from an independent dealer not a main Audi dealer so I wasn’t getting much help from them. When I took the car in for a service to Audi I did mention some of the symptoms but they didn’t really find anything wrong during the test drive. I actually took mine in a number of times to Halfords through external warranty but all they could say was that all the symptoms were due to my timing chain needing replacing as it was probably stretched. When I eventually got fed up, I took it to a specialist and he stripped the timing cover and said the chain was fine. As mentioned before, he diagnosed it as a faulty inlet cam adjuster which is why the EML would only come on intermittently with the code p0011. Ever since he changed the adjuster, it’s been perfect.
 

Paul Keenan

Registered User
@Leedavies_S3 I'm having the exact same problem here, mines is 2014 s3 55000m on the clock, basically I got this issue months ago took it to a garage and got a full service done on it, new coil packs and an engine flush and still nothing, had the inlet manifold stripped and cleaned due to carbon build up, mechanic says the flaps didn't operate properly due to the amount of carbon, anyway still getting the same problem, changed the magnetic camshaft sensor on the exhaust side of the cam and still not fixed the fault, now on sat there I have changed the pcv valve and still have the same fault, this thing is doing my head in, just want it fixed but dont seem to be getting anywhere, read of alot of people having the same problem but not one definite solution to fixing it

Any help would be much appreciated
 

AlS3BE

Registered User
@Leedavies_S3 I'm having the exact same problem here, mines is 2014 s3 55000m on the clock, basically I got this issue months ago took it to a garage and got a full service done on it, new coil packs and an engine flush and still nothing, had the inlet manifold stripped and cleaned due to carbon build up, mechanic says the flaps didn't operate properly due to the amount of carbon, anyway still getting the same problem, changed the magnetic camshaft sensor on the exhaust side of the cam and still not fixed the fault, now on sat there I have changed the pcv valve and still have the same fault, this thing is doing my head in, just want it fixed but dont seem to be getting anywhere, read of alot of people having the same problem but not one definite solution to fixing it

Any help would be much appreciated

Only thing left is the injectors. Possibly 2 sets of them on the s3.
 

Hamza_Irfan

Registered User
@Leedavies_S3 I'm having the exact same problem here, mines is 2014 s3 55000m on the clock, basically I got this issue months ago took it to a garage and got a full service done on it, new coil packs and an engine flush and still nothing, had the inlet manifold stripped and cleaned due to carbon build up, mechanic says the flaps didn't operate properly due to the amount of carbon, anyway still getting the same problem, changed the magnetic camshaft sensor on the exhaust side of the cam and still not fixed the fault, now on sat there I have changed the pcv valve and still have the same fault, this thing is doing my head in, just want it fixed but dont seem to be getting anywhere, read of alot of people having the same problem but not one definite solution to fixing it

Any help would be much appreciated

You said you’ve changed the exhaust cam sensor, have you looked at the inlet cam adjuster? That was the issue on mine.


Sent from my iPhone using Tapatalk
 

Paul Keenan

Registered User
You said you’ve changed the exhaust cam sensor, have you looked at the inlet cam adjuster? That was the issue on mine.


Sent from my iPhone using Tapatalk
No but I have my old one from the exhaust side so I could swap that out and give it a try, no harm in trying lol
 

AlS3BE

Registered User
I dont think its injector related because it only happens in the morning when the engine is cold once the engine temps are up the car works and responds fine

Not sure about the s3 but injectors seals are like a metal washer possibly copper. Like all metals it expands when hot so will provides a better seal than when cold.
Could also be semi blocked injectors and again when warm the dirt is loose where as when cold it’s stuck solid.
If you have ruled out ignitions then fuelling and air can be the only problems left.
 

Marco 99

Registered User
I've had this problem on my 2014 s3 and added injector cleaner and seems to have sorted the problem. Half a tank then put a bottle in. Done this twice and its cleaned it not before changinging the pcv valve plus couple of hundred more on other components but hey 15 quid a time for two bottles seems to have helped alot. Mine only started rough idle at temp I.e 50 degrees
 
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CDM

New Member
@Leedavies_S3 , Did you get this fixed with any of the above mentioned repairs? My S3 is having the same issues. Cheers
@Leedavies_S3 was this sorted in the end? The intake n205 correct the problem?

I have all the same, done everything of the above namely, Plugs, Coils, PCV, Catch tank - going to send the top set injectors in for cleaning within the next day or so (was done about 12 months ago)

I am curious as although im getting multiple misfires on Cyl 4 which is leading me to the injectors i had and still have this issue with the Over performance Camshaft fault (I think its P0011) which might be attributed to these listed above.
 

Leedavies_S3

Registered User
@Leedavies_S3 was this sorted in the end? The intake n205 correct the problem?

I have all the same, done everything of the above namely, Plugs, Coils, PCV, Catch tank - going to send the top set injectors in for cleaning within the next day or so (was done about 12 months ago)

I am curious as although im getting multiple misfires on Cyl 4 which is leading me to the injectors i had and still have this issue with the Over performance Camshaft fault (I think its P0011) which might be attributed to these listed above.
Forgot to update the post, it’s been a while! I changed the inlet cam magnet and it’s been fine ever since. About £50 I think it was a while ago now. Easy to change 3-4 torx bolts on left side top engine easy to do
 
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