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.
 

Harry4life786

New Member
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
 
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