Thread: Vibration on idle with Revo - S3

Hi Guys

I get and intermittent vibration on idle when my revo is on and then when I put the car back to stock it goes away.

Does anyone know what it can be?

Thanks

Is the idle speed any lower?or are there any variations in idle speed?
You should also give Revo a call.

The idle speed is normal. The car jus gets a shake or shudder. The revs stay constant. Sometimes its harsher than other times or sometimes its no existent.


It has only happened once since the car has been set back to stock.

How long ago did you get the Revo remap? Had mine just over a week and mine seems fine.

Originally Posted by BOSSS3

The idle speed is normal. The car just gets a shake or shudder. The revs stay constant. Sometimes its harsher than other times or sometimes its no existent.


It has only happened once since the car has been set back to stock.

So it happens both with Revo engaged and when stock.

Does it happen only when the engine is started from cold?

Also, based on what I have read on this forum 'stock' with Revo isn't actually stock - it is a Revo map with a lower power output.

Originally Posted by BOSSS3

The idle speed is normal. The car jus gets a shake or shudder. The revs stay constant. Sometimes its harsher than other times or sometimes its no existent.It has only happened once since the car has been set back to stock.

If it's happened since the car has been set back to stock,then the software is not the origin of the problem,and what you've described sounds more like an intermittent misfire.

How many miles has the car done since the plugs were changed(and how many miles overall)......does it misfire under load?

Originally Posted by DJ-S3

How long ago did you get the Revo remap? Had mine just over a week and mine seems fine.

Car has been remapped for over a year.

Originally Posted by Cheese

So it happens both with Revo engaged and when stock.

Does it happen only when the engine is started from cold?

Also, based on what I have read on this forum 'stock' with Revo isn't actually stock - it is a Revo map with a lower power output.

When starting from cold it seems like its misfiring for a few seconds then it clears. But it does it when the engine is warm.

Originally Posted by BOSSS3

Car has been remapped for over a year.

And how many miles have the plugs done?

Originally Posted by S3Alex

If it's happened since the car has been set back to stock,then the software is not the origin of the problem,and what you've described sounds more like an intermittent misfire.

How many miles has the car done since the plugs were changed(and how many miles overall)......does it misfire under load?

Car does it very often when the revo is on and like i say it has only happened once since I set the car back to stock. The car has about 30k miles on it. It is still under maintenace plan and the plugs were changed on the last service which was quite a while ago.

I had the ITG intake on aswell which I have taken off cause i'm sending it to Audi. How often should the plugs be changed with mods on?

Originally Posted by BOSSS3

Car does it very often when the revo is on and like i say it has only happened once since I set the car back to stock. The car has about 30k miles on it. It is still under maintenace plan and the plugs were changed on the last service which was quite a while ago.

OK....the maintenance plan is fine if the car isn't mapped or modified,but the plugs are one of the first items to go,when the boost etc is increased.

They last between 5-10 000 miles,and a misfire is one the first signs that they're a bit past their best,and on stock settings,this often reverts almost to normal....I'd suggest getting the plugs changed and seeing it clears the problem,as the next culprit is the coilpacks.

There is a lot of talk about which plugs to use,and most of the current advice is to use stock plugs,and change them at 5 000 mile intervals....mine runs 2bar boost with a bigger turbo and a lot of other mods,using stock plugs.

Originally Posted by S3Alex

OK....the maintenance plan is fine if the car isn't mapped or modified,but the plugs are one of the first items to go,when the boost etc is increased.

They last between 5-10 000 miles,and a misfire is one the first signs that they're a bit past their best,and on stock settings,this often reverts almost to normal....I'd suggest getting the plugs changed and seeing it clears the problem,as the next culprit is the coilpacks.

There is a lot of talk about which plugs to use,and most of the current advice is to use stock plugs,and change them at 5 000 mile intervals....mine runs 2bar boost with a bigger turbo and a lot of other mods,using stock plugs.

I will be sure to check the plugs and will just change them anyway cause im sure they have been in there for more than 5k miles. Really appreciate your help and input.

Originally Posted by BOSSS3

I will be sure to check the plugs and will just change them anyway cause im sure they have been in there for more than 5k miles. Really appreciate your help and input.

Very kind...thank you!

I've had a few of these things myself along the way,including the plug related misfire,and a less obvious one that was caused by airflow limitation through the stock intake,but that won't trouble you with an ITG!......also,you'd be surprised by how most dealers simply aren't bothered about things like intakes and so on.

The last time went to the local dealer,it went from one mechanic draining the oil,to suddenly ALL of them coming over to look,and not one word about warranties etc.

Apologies to the OP for hijacking the thread....but do you mind me asking whereabouts you're from Alex? I'd love to see this car of yours...if only to hear the noise of the GT3071!

Originally Posted by andywaddy

Apologies to the OP for hijacking the thread....but do you mind me asking whereabouts you're from Alex? I'd love to see this car of yours...if only to hear the noise of the GT3071!

If you're going to the Inters this year,you'll see mine and most of the other 500bhp+ club members there......S3,TT-RS,and maybe even a Golf R.

Unstable idle is mostly caused by worn plugs, but the other thing that gave me an inconsistent idle was a knackered PCV. I changed it for a catch can and the idle returned to normal. I'm not suggesting you put a catch can on it, but might be worth seeing if your PCV is OK.

At idle I can't see the Revo code adjusting any of the parameters (boost / fuelling etc.), it will only change the parameters on the fly. Worth whipping a plug out and checking it out to see what state it is in. If it looks OK then might be worth looking elsewhere. Modified if you get 15k out of a set of plugs you're doing well. They might run, but they'll be beyond their best. I know it sounds ridiculous but the TFSi engine seems to need very specific running parameters.

I've regapped my next set of plugs from 0.8mm to 0.7mm to see if it improves wear rate as many tuners of cars running high boost reduce the plug gap so can't see why these cars should be any different.

Originally Posted by warren_S3

Unstable idle is mostly caused by worn plugs, but the other thing that gave me an inconsistent idle was a knackered PCV. I changed it for a catch can and the idle returned to normal. I'm not suggesting you put a catch can on it, but might be worth seeing if your PCV is OK..

Good point about the catch can Warren....the TFSi breather system is frankly junk,and even an unmodded car would benefit from a catch can if you're keeping it for a while.
I had a can fitted to mine at around 15 000 miles,and when the engine was being rebuilt there was still a load of crap on the valve stems from prior to the catch can being there to remove all the rubbish,so it is a good idea.

Originally Posted by warren_S3

Unstable idle is mostly caused by worn plugs, but the other thing that gave me an inconsistent idle was a knackered PCV. I changed it for a catch can and the idle returned to normal. I'm not suggesting you put a catch can on it, but might be worth seeing if your PCV is OK.

At idle I can't see the Revo code adjusting any of the parameters (boost / fuelling etc.), it will only change the parameters on the fly. Worth whipping a plug out and checking it out to see what state it is in. If it looks OK then might be worth looking elsewhere. Modified if you get 15k out of a set of plugs you're doing well. They might run, but they'll be beyond their best. I know it sounds ridiculous but the TFSi engine seems to need very specific running parameters.

I've regapped my next set of plugs from 0.8mm to 0.7mm to see if it improves wear rate as many tuners of cars running high boost reduce the plug gap so can't see why these cars should be any different.

Audi changed my PCV valve end of last year so I doubt that it is the problem. The thing is the revs are constant when there is the vibration/shudder. And its not doing it now that the software is back to stock. It just doesnt make sense?? Could it be possibly that when the software is on the timing has changed and maybe that is the problem?

It's likely the software is accentuating the issue with the Audi hardware.

First places I'd check are:

> Spark plugs
> Coil packs
> MAF
> Air leaks

After those easy checks you'd have to start thinking about things like:

> Exhaust Valve springs (Recall issue)
> Throttle body alignment / clean up
> Tumble flaps in inlet manifold defective
> Defective turbo charger / wastegate????

Personally I wouldn't hold out much hope that Audi will guess right. I'd be taking it to a reputable independent first as their rates are lower and they are more atuned to fault finding that Audi ('Is there a fault code - No - the cars fine') service technicians

To be fair without a PAT tester i cant see how you can check the plugs. In my experience the insulation breaks down between the plug chassis and the electrode so that basically is the porcelain. Just change the pugs as a matter of course.

That said i am surprised if its plugs or coil packs it only does it on tickover when they are under least load. In answer to you question yes the advance curve would be altered under the remap but again as Warren says at tickover you would not be on the advance curve anyway.
Turning the boost up and advancing the ignition with the map will show up faults not necessarily connected to the map..... like DMF and mechanical issues especially as you say the revs stay steady when its vibrating..

Originally Posted by warren_S3

It's likely the software is accentuating the issue with the Audi hardware.

First places I'd check are:

> Spark plugs
> Coil packs
> MAF
> Air leaks

After those easy checks you'd have to start thinking about things like:

> Exhaust Valve springs (Recall issue)
> Throttle body alignment / clean up
> Tumble flaps in inlet manifold defective
> Defective turbo charger / wastegate????

Personally I wouldn't hold out much hope that Audi will guess right. I'd be taking it to a reputable independent first as their rates are lower and they are more atuned to fault finding that Audi ('Is there a fault code - No - the cars fine') service technicians

Thanks warren.

The car went to Audi today and you're 100% right about the plugging in the computer with no fault code. I'm definately going to change the plugs myself. If the coilpack is faulty will it log the faults?

Originally Posted by BOSSS3

Thanks warren.

The car went to Audi today and you're 100% right about the plugging in the computer with no fault code. I'm definately going to change the plugs myself. If the coilpack is faulty will it log the faults?

Yes, blocks 15 & 16 should log fault coes against misfires in particular cylinders.

Have a look through this (LINK) and go to table called ROUND 4 and this give you an idea of what to look at when logging to detect misfires.

Originally Posted by warren_S3

Yes, blocks 15 & 16 should log fault coes against misfires in particular cylinders.

Have a look through this (LINK) and go to table called ROUND 4 and this give you an idea of what to look at when logging to detect misfires.

Audi came back to me with the following:
- They asked whether the car is modded because they picking up that the car is over boosting, i said no it is stock. When I picked the car up the service advisor said to me that the technician says the car is very fast compared to other stock S3's he has driven and that they had even reflashed my ECU and it still felt very strong.
- They picked up two faults one which was the dump valve and the other which was the one injector. They replaced the dump valve and said this was causing the screech on the boost of the turbo but the screech is still there just not as bad. They say that the new injector will stop the remaining screech. They have ordered the injector because they don't have stock of it.

Firstly what I don't understand is how can the stock revo map can give elevated boost levels when it is a copy of the stock Audi map and secondly how can the injector fix the screeching noise, it will only fix the vibration on idle.

Originally Posted by BOSSS3

Audi came back to me with the following:
- They asked whether the car is modded because they picking up that the car is over boosting, i said no it is stock. When I picked the car up the service advisor said to me that the technician says the car is very fast compared to other stock S3's he has driven and that they had even reflashed my ECU and it still felt very strong.
- They picked up two faults one which was the dump valve and the other which was the one injector. They replaced the dump valve and said this was causing the screech on the boost of the turbo but the screech is still there just not as bad. They say that the new injector will stop the remaining screech. They have ordered the injector because they don't have stock of it.

Firstly what I don't understand is how can the stock revo map can give elevated boost levels when it is a copy of the stock Audi map and secondly how can the injector fix the screeching noise, it will only fix the vibration on idle.

The fact of the matter is they are probably taking shots in the dark and hoping it cures the problem. If it was a new D series DV then it won't be causing any issues unless you can tell it's stuck solid. There have been a few injector issues on S3's (can't remember if it was spray pattern or another issue), but not common. These things deliver fuel at up to 130 bar, so if there is the slightest seal leak you could get an air screech.

With Revo switched off the boost level should be exactly as per factory. The only problem you have now is because they have flashed the ECU your Revo code will be gone so will need to be reloaded.

Is there a boost control valve on these cars???? I'm not sure (used to be an N75 valve on the 1.8T), but I wouldn't know where that is. Excess boost is usually symptomatic of an air leak in the induction side (I had 27psi spikes with a split hose to the DV on my BAM engine 1.8T).

Probably worth taking it to an indy and getting them to run the car and log the boost as if you are seriously overboosting you can cause meltdown!

Originally Posted by warren_S3

The fact of the matter is they are probably taking shots in the dark and hoping it cures the problem. If it was a new D series DV then it won't be causing any issues unless you can tell it's stuck solid. There have been a few injector issues on S3's (can't remember if it was spray pattern or another issue), but not common. These things deliver fuel at up to 130 bar, so if there is the slightest seal leak you could get an air screech.

With Revo switched off the boost level should be exactly as per factory. The only problem you have now is because they have flashed the ECU your Revo code will be gone so will need to be reloaded.

Is there a boost control valve on these cars???? I'm not sure (used to be an N75 valve on the 1.8T), but I wouldn't know where that is. Excess boost is usually symptomatic of an air leak in the induction side (I had 27psi spikes with a split hose to the DV on my BAM engine 1.8T).

Probably worth taking it to an indy and getting them to run the car and log the boost as if you are seriously overboosting you can cause meltdown!

I thought they were maybe trying to call my bluff by asking if the car was modded, cause since i said it wasn't they never mentioned it again. I'm not worried if they flashed it back to stock because i already spoke to my revo dealer. I just want to see what happens when the injector is fitted? i hope that screech goes away.

Sorry i am a bit lost here .....I thopught we were looking for a vibration

"I get and intermittent vibration on idle when my revo is on and then when I put the car back to stock it goes away."

Please disregard my post no, 21 as we seem now to be looking for a screech :-)

Originally Posted by paddy

Sorry i am a bit lost here .....I thopught we were looking for a vibration

"I get and intermittent vibration on idle when my revo is on and then when I put the car back to stock it goes away."

Please disregard my post no, 21 as we seem now to be looking for a screech :-)

Hi Paddy

I had two separate problems the one being a vibration on idle and the other being a screech when the turbo starts to boost. I made a separate post about the screech, but then just joined it to this one so your earlier post is not to be disregarded.