Audi S7 Strange noise

[Emre69]

Hi all,

I'm from France and I'm 25 years old, I purchased a beautiful 2012 with 91 000 km (56000 miles) Audi S7. I love this car.. I never got 4.0 TFSI before only 4.2 FSI A8 4H. However, I hear random noise only at idle from engine.

https://youtu.be/P2XLcEudpXs (the same noise at Start and Stop)

If I turn on A/C, engine make continuous noise only at idle.

https://youtu.be/WBUGr1vJgcA

Something strange is when I left the oil cap at idle, (good suction) engine die.

https://youtu.be/iX0a5xVK1Nc

If I remove slowly but very slowly, engine Don't die but accelerate and i hear some random "tik" coming from Audi valvelift system.

And finaly, my knock sensor show strange values..



94 000km maintenance by myself

Engine Oil remplacement (5w40)
Transmission ATF + MTF oil remplacement / Transmission good condition
Sport differantial ATF + MTF oil remplacement / Differantial good condition
Oil screen removal / Turbos OK
Spark plug remplacement
PCV remplacement
Complet Fuel pump remplacement in tank
Drive belt remplacement

Clean all parts (throttle valve, intake intercooler...)

Some picture

























PS : I have got this noise when I buy the car 91 000 km.
The vehicle is currently working well, no MIL engine light or other warning light... Good acceleration, power, etc etc...

I just wonder what your views on that are. Many thanks and I'm sorry for my english.

[IowaRS7]

The HPFPs have a ticking noise to them, perfectly normal if that is what you are hearing.

[Emre69]

Thanks bu not HPFPs ticking i say, in video you can hear under the car like a chain maybe :/

[IowaRS7]

Can’t say that I hear anything in the video outside normal. I too wondered about the ticking but learned they were the HPFPs. Other things to consider if there is a concern would be exhaust leaks or boost leaks. Since the car seems to run strong a boost leak isn’t maybe as likely unless it’s so small it’s not impacting perform much.

[Emre69]

When I do the maintenance, I Don't see any boost leak. I look at the exhaust area but nothing :/ I know it's too dificult to hear with video.

[IowaRS7]

The noise is happening without the car moving correct? So nothing in the suspension or drivetrain? Some have had drive shaft bracket failure that can cause a noise but not sure it would apply here.

[Emre69]

Yes, only without car moving. The noise come between engine and transmission when I put my ear under the car.

[RAF_S7]

Have you tested the engine mounts using VCDS?

Are there any codes?

[Emre69]

With VCDS, no code with engine mounts. All clear, I just have terminal 15 on, in confort module

[Emre69]

I cut the soundtrack where the noise appear

https://youtu.be/s7tzsAXYeTQ

[gk1]

Does the noise change with revs? (belt, pulley etc) or just with the A/C? Have you checked the fans are not hitting anything?
Maybe have the A/C system checked...leaks, pressure etc.

[Emre69]

I change the belt too, check clearance etc.. No problem with A/C system. Random noise when idle no A/C, when put on A/C, constant noise.. I check fan too.

And I see this, A/C turn with engine chain...





What do you think about this hypotesis ?

[wwhan]

I change the belt too, check clearance etc.. No problem with A/C system. Random noise when idle no A/C, when put on A/C, constant noise.. I check fan too.

And I see this, A/C turn with engine chain.......

What do you think about this hypotesis ?

I cannot tell if the noise is abnormal. The 4.0T engine does have some odd noises, when operating normally.

The continuous noise with AC on, may be related to the Accessory Drive Gear Module & clutch drive to AC compressor. The Accessory Drive Gear also drives the water pump. It might not be an easy noise to chase down, unless the AC compressor is going bad.

Since you do not have any DTC codes for cam adjusters, they are probably OK, but there is a note about one of the chain glides in the summer 2018 ATU on Cam Adjusters: https://static.nhtsa.gov/odi/tsbs/20...50761-9999.pdf

The cam adjusters have been another area of concern on early S6/S7 4.0T engines.

"Chain glide rail part number 07910947A should be checked when replacing cam adjuster. Replace the glide rail if it is not part number 07910947A."

This is a different glide than the glide you pointed at & probably not relevant.

"Optimized glides used in vehicle production since April 2017 onwards."

[Emre69]

"The continuous noise with AC on, may be related to the Accessory Drive Gear Module & clutch drive to AC compressor. The Accessory Drive Gear also drives the water pump. It might not be an easy noise to chase down, unless the AC compressor is going bad"
It makes sens ! But today, noise was only at start and stop. A/C on no noise, A/C off no noise... Other day, noise is permanly when A/C on and random A/C off... And when you are under the car, a noise like washing machine appear between engine and transmission..

Thanks for document, I see that in other discussion but as you say, my cam adjuster are good, and I haven't got any DTC with VCDS..

In all cases, noise is here and I'll be following...

Just, is it normal that engine die when pull off oil cap ? I enter big air leak on engine but, it should be run ?

[wwhan]

...... Just, is normal engine die when pull off oil cap ? I enter big air leak on engine but, it should be run ?

I would normally guess PCV oil seperator, but you replaced that already.

[Emre69]

Yes I change PCV.. I just have this hose shaking a lot

[3g_bishi]

Car sounds normal, this is what you do

Drain the oil
Take a good sample and see if it has metal shavings, if it does it means something in the engine is going out, if it doesn’t it could be a chain it tensioner,
My rs7 when it’s running and I take the oil cap off I hear little clicks come from timing solenoids, this is normal the car is trying to retard the timing for loss of vacuum.
If the car hasn’t been beat up it’s way to early to need a chain or guides, I just rebuilt my rs7 4.0 and didn’t change those guides or tensioner I had 60k miles and they look great. Best of luck let us know if you find out. Another thing you can do is lift the Compressor tip and get a stethoscope or a long hose to listen to that noise to pinpoint it.


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[kpriv]

Yes I change PCV.. I just have this hose shaking a lot

That is from the low pressure fuel pump. It shakes a lot. “Normal” as far as I’m concerned.



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[Emre69]

Car sounds normal, this is what you do

Drain the oil
Take a good sample and see if it has metal shavings, if it does it means something in the engine is going out, if it doesn’t it could be a chain it tensioner,
My rs7 is it’s running and I take the oil cap off I hear little clicks come from timing solenoids, this is normal the car is trying to regard the timing for loss of vacuum.
If the car hasn’t been beat up it’s way to early to need a chain or guides, I just rebuilt my rs7 4.0 and didn’t change those guides or tensioner I had 60k miles and they look great. Best of luck let us know if you find out. Another thing you can do is lift the Compressor tip and get a stethoscope or a long hose to listen to that noise to pinpoint it.


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Good idea ! And thanks for your experience. Next time I drain the oil, I check this. I'm going to test with stethoscope.

If today or tomorow I have the horrible noise, I rec it and show you. Rebuild RS7 😍, I see a RS7 rebuild cause misfire, is it yours ?

- - - Updated - - -

That is from the low pressure fuel pump. It shakes a lot. “Normal” as far as I’m concerned.



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Oh ok good, Thanks !

[3g_bishi]

Good idea ! And thanks for your experience. Next time I drain the oil, I check this. I'm going to test with stethoscope.

If today or tomorow I have the horrible noise, I rec it and show you. Rebuild RS7 , I see a RS7 rebuild cause misfire, is it yours ?

- - - Updated - - -



Oh ok good, Thanks !

Yes sir that is indeed mine.


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[Jordanmc321]

Did you ever find this fault? I have a 2015 S7 with the same noise.

Jordan

[Emre69]

No never find this fault :/ car do same noise but no issue

[goldenzrule]

I posted about what I think is the same noise in the main c7 section. I added a vid that is a bit more clear towards the bottom of the thread

https://www.audizine.com/forum/showt...-missing-bolts

[Jordanmc321]

Thank you both. It definitely sounds like the same noise but its hard to tell with a video. I'll keep a listen out and see if it gets worse although I don't do a lot of miles in it. I'll also get it up on a lift soon and have good look/listen underneath with and without A/C running, I'll update this if I find anything.

[goldenzrule]

Thank you both. It definitely sounds like the same noise but its hard to tell with a video. I'll keep a listen out and see if it gets worse although I don't do a lot of miles in it. I'll also get it up on a lift soon and have good look/listen underneath with and without A/C running, I'll update this if I find anything.

Please do, I'd like to hear if you find anything. The random noise has worried me since I got the car, so hearing people says it's actually normal kinda puts my mind at ease a bit.

[Troy Jollimore]

If you're listening underneath the car while someone else puts it into gear while holding their foot on the brake, does the noise go away or change?

[Emre69]

Noise sound only change if press A/C and put car in Drive

After a few test, I think I know which part do this noise. It's flywheel.
Noise is random when car is in Park. When I put Drive, noise is synchronized with engine sound.
When I put A/C, engine is under A/C compressor "stress", so flywheel is under big oscillation caused by engine. If flywheel is bad, then do noise.
Sorry for my bad english but I think this is the solution of this noise...

[jh_s6]

Any updates on this issue? Emre69 I have this same issue on my 2018 Audi S6. I just got the vehicle about a month ago so I'm a bit worried as well. It sounds almost like a knocking sound and to be honest sort of like a cammed car sound as well when it gets a little rough. I can feel it inside and hear it the slightest bit but can really hear it outside of the cabin. Any help on this or someone acknowledging this is normal would really put my mind at ease haha. Thanks in advance!

[Emre69]

@jh_s6 yes, it was the flywheel !

[jh_s6]

@jh_s6 yes, it was the flywheel !

How did you go about fixing it? Or did you just leave it and deal with it? Also, did you have a very slight rough idle intermittently as well with no codes like mine in the attached video?

https://drive.google.com/file/d/1LjS...w?usp=drivesdk


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[jh_s6]

@jh_s6 yes, it was the flywheel !

Did you fix it? It so how did you end up fixing it? I’m still having it and my car is running slightly rough like a misfire when sitting and idling for a while.


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[Emre69]

Did you fix it? It so how did you end up fixing it? I’m still having it and my car is running slightly rough like a misfire when sitting and idling for a while.


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It was the flywheel. No misfire on this car. But, I've got the same issue with an RS7 (misfire at idle AC/off). AC/on, no misfire. I change a lots of thing but I can't remove this issue... Too strange

[jh_s6]

It was the flywheel. No misfire on this car. But, I've got the same issue with an RS7 (misfire at idle AC/off). AC/on, no misfire. I change a lots of thing but I can't remove this issue... Too strange

Sorry to bug you again just wondering if you ever figured out the issue with the RS7 idle or if you are just gonna live with it. Thanks in advance!


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