Help please - S3 8V hunting on idle

pop80_uk

Registered User
I need your help please

I have a 2015 manual Audi S3 8V (Standard, no engine mods)

Recently it has started hunting when on idle, the rev needle does not move but you can feel the car hunting and it feels like it's going to stall.
It only does it on idle, and seems to drive OK still.

VCDS shows no codes,

I have visually inspected the engine and I can not see anything obvious.

What I did notice though was oil on the Turbo breather pipe into the PCV (see pictures) Is this normal?

I am guessing I might need a new PCV unit?

Any ideas people its driving me crazy and does not sound healthy at all when its doing it.

Thanks in advance.


 

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pop80_uk

Registered User
Replaced the PCV and its still hunting on idle

The tacho needle does not move but you can feel the engine hunting (feels like it is going to stall)

Can anyone else help please?

Thanks
 

Marky79

Registered User
Thanks,
Is that easy to change?
Is that the Camshaft Adjuster Magnet?
Or the Sensor Turns Camshaft sensor?

Thank
Camshaft Adjuster Magnets, they’re easy mate, 6 torx and a rag to catch the oil dribbles. They’re the 2 black magnets at the chain end of the head. Let us know how you get on, I’ll bet £100 it’s them.
 

pop80_uk

Registered User

Marky79

Registered User
Thanks, really appreciate you help! :icon thumright:
So I need two of the same?
I assume its these:
https://www.ebay.co.uk/itm/New-Genu...149534&hash=item2d18ba6794:g:qjcAAOSww-lfcy9E

Part number? 06L109259A

Thanks again, I will get some ordered once I hear back :icon thumright:
Yeah that’s them. But I ordered the OEM from autodoc, peirburg or febi bilstein. Link below.if you order Monday they’ll be with you by Friday at the latest, saves £50.

https://m.autodoc.co.uk/febi-bilstein/7556412
 

pop80_uk

Registered User
Yeah that’s them. But I ordered the OEM from autodoc, peirburg or febi bilstein. Link below.if you order Monday they’ll be with you by Friday at the latest, saves £50.

https://m.autodoc.co.uk/febi-bilstein/7556412

Thanks
I have ordered two from them, hopefully they will come soon :)

I will let you know how I get on.

Where about are they located? I know where the one is I think but not sure on the second one.

Thanks
 

Marky79

Registered User
Thanks
I have ordered two from them, hopefully they will come soon :)

I will let you know how I get on.

Where about are they located? I know where the one is I think but not sure on the second one.

Thanks
Both are on the right hand side of the camshafts(left as you look at the engine). One for exhaust and one for inlet. A 30min job, just don’t drop the screws, and put a cloth under as they’ll leak a wee bit of oil.

please do reply, as to many people let threads die without reporting back.
 

pop80_uk

Registered User
All fitted, and after a quick drive it appears your a genius @Marky79 as it appears to have fixed the problem

I did compare the old and the new and the centre pin seemed alot looser in the old units, I also just moved the expansion tank aside for easier access.
Any idea why they fail?

It also seems a little smooth to drive (although that might be a placebo)

Thanks again for all your help! Big thumbs up!

Would you believe it though, just as thats fixed, the boot hand has stopped working and boot wont open so something else to get fixed!

(Just incase anyone is interested, I have posted a couple of pictures of the location of these magnetic cam sensors)
 

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Marky79

Registered User
All fitted, and after a quick drive it appears your a genius @Marky79 as it appears to have fixed the problem

I did compare the old and the new and the centre pin seemed alot looser in the old units, I also just moved the expansion tank aside for easier access.
Any idea why they fail?

It also seems a little smooth to drive (although that might be a placebo)

Thanks again for all your help! Big thumbs up!

Would you believe it though, just as thats fixed, the boot hand has stopped working and boot wont open so something else to get fixed!

(Just incase anyone is interested, I have posted a couple of pictures of the location of these magnetic cam sensors)
Excellent news Pop, they’re a simple cheap fix to what is a common problem on these engines. I suppose the magnets get weaker over time maybe, but that’s just a guess. The car will definitely feel smoother are the cam timing will be sharper now.

All’s well that ends well.
 

Damo S

Registered User
Excellent news Pop, they’re a simple cheap fix to what is a common problem on these engines. I suppose the magnets get weaker over time maybe, but that’s just a guess. The car will definitely feel smoother are the cam timing will be sharper now.

All’s well that ends well.

Might do the same to mine. I find the midrange torque, including the off boost response, is a little up and down but tends to be normal when the weather is hot, or the car has had a bit of a ragging. The top end power is not really affected. Does this sound about right as symptoms?
 

pop80_uk

Registered User
Might do the same to mine. I find the midrange torque, including the off boost response, is a little up and down but tends to be normal when the weather is hot, or the car has had a bit of a ragging. The top end power is not really affected. Does this sound about right as symptoms?

Its worth a try, cost me £55 for both magnetic camshaft adjusters. But I would also look at your diverter valve as they are prone to wear too, you can change all three yourself for less than £100

I would also note something else which has improved since changing the magnetic camshaft adjusters and thats the Auto stop start, it would work imetrimitely before and sometimes not at all. Since changing them, its fully working again and silky smooth.

Interesting side effect of the change.
 

Craig_s85

Registered User
How bad was yours hunting? Im sure i notice a little dip in mine on idle,almost like a slight miss fire,never sounds like it's going to stall though.
 

pop80_uk

Registered User
How bad was yours hunting? Im sure i notice a little dip in mine on idle,almost like a slight miss fire,never sounds like it's going to stall though.

It started off exactly as you describe, started off quite minor and not often and then got worse and worse, but it started off like yours.
 
Hi guys, having a similar idle issue. I have been advised that the magnets need changing. My question would be, do I also need to change the control valves too or should I be okay just having the magnets done?

If I do do need to change them is there any suggestion as to where as the above link are currently out of stock.

Stealers quoted me £62 per magnet and £54 per valve

Thanks in advance
 

Shuaibashraf

New Member
Hi guys sorry to bring this up again I’m experiencing the same kind of issue so it started of very minor on cold start once my revs dropped I will get a slight judder but now it’s pretty bad and won’t go away until car is warmed up (oil temp etc) is this a sign of cam magnets ?
 

Shuaibashraf

New Member
Hi guys sorry to bring this up again I’m experiencing the same kind of issue so it started of very minor on cold start once my revs dropped I will get a slight judder but now it’s pretty bad and won’t go away until car is warmed up (oil temp etc) is this a sign of cam magnets ?
My car is a 2018 btw
 

Shuaibashraf

New Member
Yeah I’m going to be getting them from Audi directly, also having this sign come up now and then it says vehicle electronics fault shift to P could this be part of it


Sent from my iPhone using Tapatalk
 

s3x Ba

New Member
Hi,

Another one of the same me thinks - hunts on idle - seems to right itself every 10 seconds or so then fails again, rev needle moving between 700-900 and feels like crap - Driving feels a little lumpier that usual and DSG seems more hesitant somehow. It's got gradually worse until the point where it has died a couple of times when coming to a stop. Also might be worth mentioning with the bonnet popped, when it appears to right itself, there's an audible click sound from the magnet area (like a solinoid noise) which definitely makes me think its this problem, then my usual garage ran diagnostics and came to the same conclusion.

However, they've quoted me £370 to fix it! Normally theyre really good to me as ive been going there for years and have a good relationship but this quote doesnt marry up with what im reading..

Any thoughts to add?
 

Shuaibashraf

New Member
The magnets from Audi dealers are £117 for both mate labour shouldn’t be more then £50 it’s a 15 minutes job


Sent from my iPhone using Tapatalk
 
Hi guys, having a similar idle issue. I have been advised that the magnets need changing. My question would be, do I also need to change the control valves too or should I be okay just having the magnets done?

If I do do need to change them is there any suggestion as to where as the above link are currently out of stock.

Stealers quoted me £62 per magnet and £54 per valve

Thanks in advance
Having the same problem with mine, I used a basic code reader and it pointed to a fault with one of the camshaft position sensors, the one closest to the front of the engine bay. I replaced it and I’m still getting intermittent rough idle, do you think it could be faulty control valves causing the issue?
 

Marky79

Registered User
Having the same problem with mine, I used a basic code reader and it pointed to a fault with one of the camshaft position sensors, the one closest to the front of the engine bay. I replaced it and I’m still getting intermittent rough idle, do you think it could be faulty control valves causing the issue?
did you not do both at the same time?
 
these usually don’t throw codes up tbh, that’s why the issue was so hard to diagnose. You should’ve changed both.
these usually don’t throw codes up tbh, that’s why the issue was so hard to diagnose. You should’ve changed both.
I’m going to change timing chain, car has just reached 90k and I’m going to change the 2 vvt oil control valves at the same time, might be wise to change the other cam shaft position sensor while I’m at it. If this does not fix the problem I don’t know what to do, I’ve driven the car today and it seems fine, but then tomorrow it will start intermittently idling rough
 
Marky, I am getting intermittent hunting on idle, I have replaced the mag position sensors and the solenoids, pcv valve, map sensor and a new air filter. I have a video taken from vagcom of the car requesting a position of 15degrees on idle and it’s actual recorded position is fluctuating between 4 degrees and 35 degrees. The cam in bank one isn’t actually doing this. What the heck is causing this? A previous bad remap? An electrical fault? I can’t post the video on here for some reason
 
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