Facelift FL Tick / Rattle

[Aoon_M]

Good info, however doesn't really explain why it is rattling? Surely every car with a vacuum wastegate doesn't make this sound?

It’s rattling because the wastegate is open by default instead of being closed. When it’s open the gate isn’t resting against anything, when it’s shut it is resting against something and can’t move.

The pulses from the firing order when the gate is open create the ticking noise. It’s all harmonics.

 

[Aoon_M]

I don’t know of any other cars that use vacuum wastegates tbh. I expected them to use electronic wastegates like the EA888.3 but maybe it couldn’t withstand the heat long term in this application

 

[Aoon_M]

Be lovely to think Audi would accept this as something that needs investigating?
It's a noise that's always there, it's just only heard when the cat is removed. Surely they would have heard it while testing?!. Not sure at what stage they are tested. I have never heard of a car that cannot have it's cat removed. Maybe it was done on purpose as part of a scheme to prevent people doing it based on emissions?!.

I don’t think Audi care if a sound is heard with the cat removed tbh. They designed the car to be run with a cat.

 

[H4RDYRS3]

Thanks for clearing that up Aoon

 

[c2wak]

I don’t think Audi care if a sound is heard with the cat removed tbh. They designed the car to be run with a cat.

Yeah I agree. Was a Nice thought though. Think am just gonna have to put it back on. Thanks for the explanations though. Doesn't make me feel any better about not being able to do what I want with it though.
What I don't get is.. I contacted armytrix and bullx via hg and they claim there is no noise with their systems.
I'm not about to spend 3k+ to chance this.

 

[KKOG]

It's not a solution but one thing that maybe could help dampening the sound a little bit is to mount the oem under hood insulation from the s3.
The rs3 doesn't have the insulation from factory.

The s3/rs3 sportback and s3/rs3 saloon have the same hood.
s3/rs3 SB hood art.nr: 8V0 823 029 D
s3/rs3 saloon hood art.nr: 8V5 823 029 A

Insulation s3 sportback art.nr: 8V0 863 825
Clip insulation s3 art.nr: 8E0 863 727 A

 

[c2wak]

I'm pretty sure the noise on low revs post decat is different from the cold start chuff. I have decided the cold start is more of a chuff. The low rev post decat noise is a tick.

 

[RGJB]

Hi guys,

Hoping to get some more feedback from this thread, hopefully there's some people still lurking around.

I bought my RS3 sedan in September last year. The car is completely stock, and has since the beginning has suffered from the loud ticking on start up as all RS3s seem to, but it also suffers from the same sound whenever I apply throttle while driving around (not in neutral/park, only when moving). This is most noticeable between about 1500 and 2500 RPM, and is much louder when the exhaust is in dynamic mode. Starting up the car in dynamic mode, and driving in dynamic mode (as opposed to individual mode with the exhaust set to dynamic) make the sound quieter, but do not get rid of it.

I (and the dealership) initially suspected this was due to an exhaust issue and the car underwent the silencer swap. This has not fixed the rattle, and the dealership have basically thrown their hands up in the air and told me there's nothing they can do. Having taken on the task of trying to figure it out myself I have stumbled on this thread, which seems to be the most relevant/useful bit of info I've found so far (suggesting that the turbo wastegate might be the issue, rather than the exhaust as initially suspected).

The sound is really quite loud with the windows down / roof open, and it's pretty embarrassing when driving away at a set of lights. I'm wondering if Australia has a different cat system / no secondary cat, hence why it's so loud on the stock system (this doesn't seem to be an issue on NA cars). Having said that, I know not all Australian RS3s do this. I'm currently liaising with Audi Australia to see if they can help.

Do you guys have any solution for the sound yet, and do you think that if the rattle is present when actually driving that the performance of the engine/turbo will be negatively affected?

Thanks very much for any replies!

 

[Dan_DJT]

What you describe is normal and mine does exactly the same. My view (based on 20yrs working in engine calibration) is that the sound is related to a combination of exhaust gas pulses, variable valve timing, catalyst heating mode (retarded ignition/injection) and the large bore of the exhaust system. It kinda sounds like each exhaust pulse bounces of the wall of the exhaust at low mass flows. These cars have to meet very strict emissions limits which means the catalyst has to be kept hot at all times and I think this is mainly done with retarded ignition at the lower engine speeds. In dynamic mode the ECU appears to run a different set of maps and the noise is reduced.

Obviously just my opinion but I dont think there is a fault with the car, just the calibration Audi have done is not as good as it should be. It is a very advanced engine what with Variable vale timing and lift, port and direct injection, swirl flaps etc. and a lot of parameters to calibrate.

It is an annoying sound and it is a shame that Audi decided to release it with such an obvious noise issue, despite that it is still one of the best engines around, drives fantastic and the noise at higher revs makes up for the poor low speed noise.

 

[RGJB]

Hi Dan, and thanks for your reply.

I wondered if you have any thoughts on the performance impact of the issue. It seems are less blaming of the wastegate, and more of the exhaust system itself (suggesting there's probably no power loss in affected cars). I do find it interesting that some other RS3s I've encountered don't make the noise despite being the same exhaust spec/configuration etc, I'm happy there might be a difference that can be corrected.

Do we have a general consensus on if the issue is contributed to in any way by the suspected wastegate fault, or has that been disproven?

 

[Dan_DJT]

I really dont think there is any impact on performance. If you drive a little harder the noise goes and if in dynamic it pretty much disappears. If there was a hardware fault it would be more consistent.

 

[T-800]

As Dan has already said really......

I had a long discussion re Wastegate with a uk turbo company regarding the start up rattle, they described to me that the ‘gate’ part is usually a ‘loose’ fit on the pivot arm, he pointed out that exhaust gas flow at start up could play a part in the noise, as would engine retardation to heat the cat up quickly.

I do feel the start up sequence has a hand in it because I used to hear the noise stop instantly on mine as the high idle settled down.

What’s interesting for me is since fitting the AVC controller for the flaps/valves I do not get the start up noise by simply going out starting the car up with the flaps open.....

Have never had the rattling at low revs issue though, although it’s been reported by people who fitted a DP to increase the low speed rattle..

 

[Slowracer]

It's not a solution but one thing that maybe could help dampening the sound a little bit is to mount the oem under hood insulation from the s3.
The rs3 doesn't have the insulation from factory.

The s3/rs3 sportback and s3/rs3 saloon have the same hood.
s3/rs3 SB hood art.nr: 8V0 823 029 D
s3/rs3 saloon hood art.nr: 8V5 823 029 A

Insulation s3 sportback art.nr: 8V0 863 825
Clip insulation s3 art.nr: 8E0 863 727 A

I was considering installing the insulation. But I was wondering why it wasn’t used by Audi, is it because the rs3 engine bay produces more heat and insulation will slow down dissipation?

 

[KKOG]

Good question.
The insulation isn't heavy. Probably just a couple of hundred grams. So it chouldn't be about that.
And its not like its going to melt because of the temperature from the 5 cyl compared to the 4 cyl.

Could be as you say but in the end it is a decition from Audi related to cost for sure. As everything else in the world.

 

[deepy]

I was considering installing the insulation. But I was wondering why it wasn’t used by Audi, is it because the rs3 engine bay produces more heat and insulation will slow down dissipation?

Good question.
The insulation isn't heavy. Probably just a couple of hundred grams. So it chouldn't be about that.
And its not like its going to melt because of the temperature from the 5 cyl compared to the 4 cyl.

Could be as you say but in the end it is a decition from Audi related to cost for sure. As everything else in the world.

Hi Guys,
I've been in touch with Audi Customer Services, regarding the fitment of the S3 bonnet insulation to the RS3 as I also thought about doing this mod. I heard back today and was advised NOT to retrofit the insulation as this may cause the engine to overheat. So @Slowracer it appears that you were right about the dissipation of the under bonnet heat produced from the 5 cyl engine.​

 

[Slowracer]

Hi Guys,
I've been in touch with Audi Customer Services, regarding the fitment of the S3 bonnet insulation to the RS3 as I also thought about doing this mod. I heard back today and was advised NOT to retrofit the insulation as this may cause the engine to overheat. So @Slowracer it appears that you were right about the dissipation of the under bonnet heat produced from the 5 cyl engine.​

Thanks for checking. My a45 was the same, no insulation due to under bonnet temps. After a hard drive you could almost fry eggs on the front of the bonnet, just above where turbo was located.

 

[G Star]

Hi Guys,

So I have just come across this forum after trying endless things to fix the rattle on my car. I wish I had come across this forum sooner! I have exactly the same problems as everyone here. I have an RS3, miltek decat, stage 2 remap and still having this rattling sound. I cannot live with this sound.

Has anyone found a fix for this yet, any suggestions would be greatly appreciated!

 

[AudiNutta]

Hi Guys,

So I have just come across this forum after trying endless things to fix the rattle on my car. I wish I had come across this forum sooner! I have exactly the same problems as everyone here. I have an RS3, miltek decat, stage 2 remap and still having this rattling sound. I cannot live with this sound.

Has anyone found a fix for this yet, any suggestions would be greatly appreciated!

There is a member of another forum that I am in contact with, there isn’t a fix for this wastegate rattle when you have decat.

He is fixing his by purchasing a complete Iroz Motorsports turbo kit to take his car to 800bhp on pump fuel. Seems to be only a new turbo / wastegate will fix it.

 

[DW81]

Read it an be mapped out on a stage one map. That’s if you want to go down this route

 

[Seanix]

Read it an be mapped out on a stage one map. That’s if you want to go down this route

Not quite. The cold start rattle can be mapped out ( they disable cold start ) not the rest.
If going decat, U will hear the rattle through all gears when in comfort mode.
In dynamic it just muffles the rattle which is still present but is overridden by the exhaust note.

I've tired both catted and decat. The decat rattle was really bad to I switched out. My cold start is disabled so at least it's a win there.

Even with a catted DP, U will hear the rattle in comfort mode but it's no where as bad as decat obviously.

Hope that helps.

Cheers



Current - 2018 RS3 Sedan
Past - 2016 RS3 SB

 

[AlwaysBeenS3]

Got the same problem, its ridiculous to be honest, even with the regulations that they have to meet any car let alone the RS3 should sound like this, its embarrassing when starting up and even driving off

We shouldn't have to start up or even drive in Dynamic to mute this problem

On the sports exhaust what can be done to cure it as I cant seem to find a definitive answer?

- Recoding of software so the exhaust valves are always open?
- Remap? Dont want to remap as it will void warranty

No point taking it into Audi if they feel its "normal" and that "they all do it"

A joke to be honest from such a car

 

[AudiNutta]

Got the same problem, its ridiculous to be honest, even with the regulations that they have to meet any car let alone the RS3 should sound like this, its embarrassing when starting up and even driving off

We shouldn't have to start up or even drive in Dynamic to mute this problem

On the sports exhaust what can be done to cure it as I cant seem to find a definitive answer?

- Recoding of software so the exhaust valves are always open?
- Remap? Dont want to remap as it will void warranty

No point taking it into Audi if they feel its "normal" and that "they all do it"

A joke to be honest from such a car

Nothing at all, all the info you need is in this thread if you take a look. I believe if you open the valves all of the time it reduces the tick, mine have been like this from day 1 and mine ticks.

Can stop the start up rattle by mapping out the cold start.

If you have a decat and the terrible rattle low down, need a different turbo / wastegate to fix.

 

[T-800]

Got the same problem, its ridiculous to be honest, even with the regulations that they have to meet any car let alone the RS3 should sound like this, its embarrassing when starting up and even driving off

We shouldn't have to start up or even drive in Dynamic to mute this problem

On the sports exhaust what can be done to cure it as I cant seem to find a definitive answer?

- Recoding of software so the exhaust valves are always open?
- Remap? Dont want to remap as it will void warranty

No point taking it into Audi if they feel its "normal" and that "they all do it"

A joke to be honest from such a car

Active valve controller stops it.
However it ain’t cheap, but to me it’s an added benefit of having one.

So the car can be started in dynamic etc but a double press of the ESC button closes the valves for a quiet start & no rattle.

 

[AudiNutta]

Active valve controller stops it.
However it ain’t cheap, but to me it’s an added benefit of having one.

So the car can be started in dynamic etc but a double press of the ESC button closes the valves for a quiet start & no rattle.

I always thought it was the other way around, valves open reduces the rattle? That’s why when all the stock cars start in comfort (valves closed) the rattle is bad?

Anyway I just put it down to a characteristic and doesn’t bother me. People in work say it sounds like a bag of nails and in general the car sounds like the exhaust is blowing.

 

[T-800]

I always thought it was the other way around, valves open reduces the rattle? That’s why when all the stock cars start in comfort (valves closed) the rattle is bad?

Anyway I just put it down to a characteristic and doesn’t bother me. People in work say it sounds like a bag of nails and in general the car sounds like the exhaust is blowing.

I’m on about if you have the Cete AVC fitted

However with the Standard car...........

Start up without pressing the Drive select as you know you’ll get rattling
Press drive select before start up to put the car into either Dynamic or individual (assuming you have engine/exhaust set to dynamic also) = no rattle, why ? Because the car is building a tiny amount of boost(look at your boost gauge on cold start it’s moving a tiny amount)
However if you cycle quickly back into comfort you’ll hear the rattle come straight back because the engine stops building boost(again you’ll see the boost gauge stop showing boost).

 

[AlwaysBeenS3]

Thanks for the guidance

I may be going to see Alix at VagCarCoding soon

Is there any software coding that can be done to stop the rattling on start up and on driving in comfort mode?

 

[T-800]

Thanks for the guidance

I may be going to see Alix at VagCarCoding soon

Is there any software coding that can be done to stop the rattling on start up and on driving in comfort mode?

No nothing I’m aware of.

 

[AlwaysBeenS3]

I was thinking that coding the valves to be open all the time will stop the rattle?

A lot of vag cars u can code to have the valves open but not sure if it can be done on rs3

 

[T-800]

I was thinking that coding the valves to be open all the time will stop the rattle?

A lot of vag cars u can code to have the valves open but not sure if it can be done on rs3

Not possible on the RS3.

If you select Dynamic on cold start it won’t rattle because the car is building a small amount of Boost(look at your boost gauge)
Select Comfort and it’ll stop building boost and rattle like a bag o nails

Slight different in wastegate position / retarded ignition timing makes the difference.

 

[Aoon_M]

The rattle comes from the wastegate, it is a vacuum actuated wastegate now instead of boost actuated. You need to understand how boost actuated wastegates work really but I will explain the best I can!

On a pre facelift RS3 8V with its boost actuated wastegate it remains shut when the duty cycle of the n75 is zero. It is fail safe this way. So on a cold start, the wastegate is shut.

On a facelift car the wastegate is reversed as it is vacuum so with n75 duty cycle zero on cold start the wastegate is wide open and it rattles.

Mappers need to set the wastegate duty cycle to 100 on cold start to stop this from happening. The reason its wide open on cold start is all to do with emissions and to get the cats up to temp as fast as possible.It is impossible to have the wastegate open on a cold start on a boost actuated wastegate


When you put a fl car into dynamic after its cold start cycle the wastegate jams shut (duty cycle 100) to aid spool! In comfort it stays open, its a very complex backwards system they have in the new engine but all for emissions purposes

Went from talking about this almost 2 years ago to launching my own company and applying the fix under all of my calibrations. Proud moment!

 

[VtecAbuser]

**** just got real!!

 

[Jem Needham]

Has anyone had any joy with this? Just bought a late 2017 RS3, cold start rattle doesnt bother me but the lower RPM one when warm really ****** me off!

Doesnt sound right, i raised it on my test drive and got the standard "its normal" response.

 

[Dan_DJT]

Only fix I know of is to have the engine remapped

 

[Jem Needham]

Ball ache, so if i moan like **** to the dealer theres nothing they will do? Read in some cases Audi had noted its an issue, thought there might be an official fix by now.

 

[Jem Needham]

Mines pre-OPF. It’s only when I’m cruising in town I notice it to be honest, in dynamic it disappears.

Debating mods at the moment, would love a full ABT makeover (cost depending) which i assume would solve the problem and push it over 500 break.

 

[Sequence]

Mines pre-OPF. It’s only when I’m cruising in town I notice it to be honest, in dynamic it disappears.

Debating mods at the moment, would love a full ABT makeover (cost depending) which i assume would solve the problem and push it over 500 break.

Best part for 20k+ for the abt kit

 

[D0C]

Best part for 20k+ for the abt kit

Might as well go full stage 3+ and pocket the change.

 

[Jem Needham]

**** that haha never know might win the lottery! I can only get REVO where i live anyway now so will probably go with them.

 

[Tonka332]

I am stage 2 FL with a scorpion decat.
Zero wastegate rattle in any mode or driving.
I just had a custom code instead of a flash. 1st thing I asked was can you code it out.
To me the WG rattle was more important to me as its a daily.

 

[AlwaysBeenS3]

I believe there is a recall on the exhaust rattle mate and it would involve replacing the whole backbox

Best thing is to take it down to your local dealer and demonstrate it to them and the service technician rather than rely on them trying to find it themselves