TFSI 140 COD: vibrations in 2-cyl mode

[LuisM]

Hi all,

First message on this forum. Sorry about my English.

I have an A3 (8V) 1.4 TFSI 140 bhp Cylinder-on-Demand (COD). I've noticed some rattle or vibration from the engine when running on 2-cylinder mode and stepping lightly on the throttle in the 1500-2000 rpm regime. If you increase pressure on the throttle the engine engages all 4 cylinders and the vibration disappears. Also, above 2000 rpm the vibration is not noticeable even in 2-cylinder mode.

I'm pretty sure this is common to all units of this engine in the A3 or in the Golf VII (the engine is called there ACT - Active Cylinder Techonology, but it's the same as COD) . Some examples of people reporting this:

- Rumble and Vibrations, Golf7 TSI 140 DSG Seite 3 : I'm just interested if I should contact my dealer about the up... This link talks about a software update that reduces the problem
- (In Spanish. Refers to Golf VII with the same engine) Crítica personal 1.4 TSI ACT [Archivo] - Club VW Golf España
- (In French) Que pensez vous que l'Audi A3 1.4 TFSI CoD - A3 - Audi - FORUM Marques

How do you get by with these vibrations? Do you find them annoying? They are moderately annoying for me. Do you try to always run the engine above 2000 rpm to avoid them? Has anyone had a software update that solves or reduces this issue?

Cheers,

Luis

 

[cuke2u]

I don't have any vibrations or rattle at all with my COD 1.4, but my car is manual. Rattles though, from the gearbox, seem to be quite common with many DSG equipped cars..

 

[LuisM]

Thanks for your reply! Mine is manual too. Yes, I heard in DSG there are more vibrations. That may also be caused by the DSG always trying to engage a hight gear.

Are you sure you don't have those vibrations? They are sligth, so you may not have noticed. If you don't mind, you could do a test: drive at about 1700 rpm and step on the throttle a little, so that you notice some acceleration, but not too much, so as to keep the 2-cyl indication on the display.

I don't have any vibrations or rattle at all with my COD 1.4, but my car is manual. Rattles though, from the gearbox, seem to be quite common with many DSG equipped cars..

 

[Pintman]

Isn't that roughly the same revs that the turbo 'kicks' in??.

Just a thought!.

 

[cuke2u]

Thanks for your reply! Mine is manual too. Yes, I heard in DSG there are more vibrations. That may also be caused by the DSG always trying to engage a hight gear.

Are you sure you don't have those vibrations? They are sligth, so you may not have noticed. If you don't mind, you could do a test: drive at about 1700 rpm and step on the throttle a little, so that you notice some acceleration, but not too much, so as to keep the 2-cyl indication on the display.

If they are slight I would put it down to an engine running as a two cylinder that is unlikely to be quite as smooth as a four cylinder, as engineering will show..

 

[LuisM]

Well, the vibrations disappear as soon as the engine goes from 2- to 4-cylinder mode (by pressing increasing throttle pressure). So it clearly has something to do with the 2-cyl mode.

 

[LuisM]

Sure! I also think it's something normal in a two-cylinder engine. I didn't mean it's something strange. I was just asking what do you people think about it, if you find it annoying, moderately annoying, or not at all; if someone has had a software update that alleviates the vibrations, etc

 

[dkpeter]

I have the 1.4CoD and stronic and do feel vibration when the 2cyl mode is activated and at times find it annoying but just as worried about if this could damaged the engine some how.

 

[cuke2u]

How do you think any damage would occur, I am sure that the engines are tested to destruction....

 

[screenbubble]

I read somewhere that early attempts at car engines with cylinder deactivation did vibrate them to destruction.
However looking at the video below it seems with the Audi COD it's the small valves that stop, and the heavy cylinders keep moving as normal. So I'm not sure where any vibration could come from, looking at the animation.
Maybe it should be called valve on demand, VOD!

Audi A1 Sportback cylinder on demand - Animation - YouTube

 

[dkpeter]

How do you think any damage would occur, I am sure that the engines are tested to destruction....

I'm sure that audi has done their work and tested. I tested the 1.4CoD with manual gearbox and didn't notice the activation/deactivation of 2cyl mode. Only way to see was on the km/L usage.

I need an automated gearbox so ordered with stronic. With the stronic I feel the activation/deactivation as vibration. The vibration are more pronounced just before the system decides to go from activation to deactivation.

I can feel the vibration in the driver seat through my behind.

Some has mentioned the DSG as the reason for the vibration but the are clearly related to the 2cyl mode as vibration disappears as soon as the car goes up hill a bit and 4cyl is enabled.

 

[leosayer1]

I do hear a slight change in engine noise when the 2 cylinder mode is engaged. You could call it a rattle but it's barely detectable and I wouldn't call it a vibration. This is with the s-tronic gearbox.

Annoying? Not at all. The engine is the most refined 4 pot I've ever driven, whether in 2 or 4 cylinder mode.

 

[cuke2u]

I agree with you that the engine is the most refined and the quietest I have ever owned too. Perhaps this is why to some sounds can be heard. To be honest I think the car should just be driven how it should and if anything that may happen be taken care of under the warranty when, and if, something actually drastically goes wrong...

 

[LuisM]

I have the 1.4CoD and stronic and do feel vibration when the 2cyl mode is activated and at times find it annoying but just as worried about if this could damaged the engine some how.

I need an automated gearbox so ordered with stronic. With the stronic I feel the activation/deactivation as vibration. The vibration are more pronounced just before the system decides to go from activation to deactivation.

I can feel the vibration in the driver seat through my behind.

Some has mentioned the DSG as the reason for the vibration but the are clearly related to the 2cyl mode as vibration disappears as soon as the car goes up hill a bit and 4cyl is enabled.

I think with Stronic the vibration may be more pronounced than with manual gear, because the automatic gearbox tends to favor low rpm regimes, where vibrations are more noticeable. Specifically, I notice them under 2000 rpm while in 2-cylinder mode

If you have drive select (I have manual without drive select), maybe using a different driving mode may help avoid the low rpm regime in 2-cylinder mode.

And then there's the thread I mentioned in my first post, where they mention a software upgrade (for the Golf VII) that reduces the vibrations. I'll mention it to the dealer when I take the car for service

 

[dkpeter]

I think with Stronic the vibration may be more pronounced than with manual gear, because the automatic gearbox tends to favor low rpm regimes, where vibrations are more noticeable. Specifically, I notice them under 2000 rpm while in 2-cylinder mode

If you have drive select (I have manual without drive select), maybe using a different driving mode may help avoid the low rpm regime in 2-cylinder mode.

And then there's the thread I mentioned in my first post, where they mention a software upgrade (for the Golf VII) that reduces the vibrations. I'll mention it to the dealer when I take the car for service

There is difference between the drive select modes and also a difference if I use CC or not to maintain constant speed.

The software update that you mentioned I find very interessing.

 

[cuke2u]

When were your cars built as it maybe that 2014 cars had a different map. The Golfs mentioned in that thread all seem to be 2013. Can anyone confirm when TPI 2036911/1 was issued for the Golf?

 

[LuisM]

I have tested with CC on, and I think the vibrations are less pronounced, or even non-existent. Is that what you meant?

What differences do you find between Drive Select modes? Is there a mode when vibrations are smaller or even disappear? (I don't have Drive Select, so I can't test)

There is difference between the drive select modes and also a difference if I use CC or not to maintain constant speed.

The software update that you mentioned I find very interessing.

 

[dkpeter]

The vibrations are most pronounced in efficiency mode or auto driving at around 70-75km/t with the CC enabled, the stronic will be in D6. When driving above the 90km/t the vibrations become non-existent.

I don't think that the drive select makes the difference in the vibrations but more the speed and gear combination. The CC enabled properly makes it worse due to 2cyl mode is entered more frequenctly.

I have tested with CC on, and I think the vibrations are less pronounced, or even non-existent. Is that what you meant?

What differences do you find between Drive Select modes? Is there a mode when vibrations are smaller or even disappear? (I don't have Drive Select, so I can't test)

 

[mfspen]

When were your cars built as it maybe that 2014 cars had a different map. The Golfs mentioned in that thread all seem to be 2013. Can anyone confirm when TPI 2036911/1 was issued for the Golf?

I have a Golf GT 1.4 ACT (manual), which has the same engine, purchased May this year.
I have not noticed any vibration in 2 cylinder mode, at any revs. In fact, I have found it completely impossible to tell when the engine is in 2 cylinder mode, other than by observing the message on the display.

 

[cuke2u]

Which is what other owners have noted as well as in road tests...

 

[dkpeter]

Booked a time at Audi dealership to have them investigate the vibrations. The service advisor informed me that I was not the only one with vibrations problem in 2.cyl mode and that they are in an ongoing investigation and dialog with Audi.

 

[cuke2u]

I hope they find a fault with your car and fix it but what the service adviser has stated is news to me and this forum...

 

[LuisM]

Well, that dkpeter is not the only one with vibrations is no news at all, as the present thread and this other show.

The fact that Audi is investigating it can hardly be any news either. There's a an issue (a minor one, I admit) with the engine, so of course they should be investigating it.

 

[LuisM]

I am very very interested in what they will you, dkpeter. Please post here if you have any other news in the future!

I also went to my dealer, but all I got from them is that vibrations are normal in a 2-cyl engine; that that's a price you pay for lower petrol consumption. And so it may be; but if something can be done to reduce vibrations (even at the cost of a reasonable increase in consumption), I'm interested.

 

[dkpeter]

So I have returned from Audi after having a mechanic with me for a drive. He acknowledge (but of cause the vibration wasn't as pronounce as it can be) that there is vibrations but as Audi is investigating and working on a solution they cannot do anything on less is it something extra ordinary. I was told that Audi is working on a software upgrade that should fix the "comfort problem" as it was described. They where under the impression that the upgrade should be ready within a month or so.

 

[LuisM]

Thank you for informing. This is good news!

I also went to my dealer, and of course they said the vibrations were within normal range. Please let me (us) know if they contact you when the software upgrade is ready, so that I can go to my dealer again to have that update in my car.

So I have returned from Audi after having a mechanic with me for a drive. He acknowledge (but of cause the vibration wasn't as pronounce as it can be) that there is vibrations but as Audi is investigating and working on a solution they cannot do anything on less is it something extra ordinary. I was told that Audi is working on a software upgrade that should fix the "comfort problem" as it was described. They where under the impression that the upgrade should be ready within a month or so.

 

[dkpeter]

Just got a call from Audi this morning . They got an update ready for me that should address the vibrations. Schedule for 25. nov

 

[leosayer1]

Well done, I hope it fixes it for you.

Don't forget to ask them to change the engine mapping to 150ps while you're there!

 

[LuisM]

Thanks for informing, dkpeter. If you can, tell us the code of the update, so that the rest of us who experience the vibrations can go to our dealers and have that update applied too. Also, please tell if the vibrations are reduced with the update. I hope so!

Just got a call from Audi this morning . They got an update ready for me that should address the vibrations. Schedule for 25. nov

 

[Muchas]

Hi dkpeter, I am really interested to know the outcome. please share.

I have had my car from new for 4 weeks now (Audi A3 1.4 COD) and from 600miles I noticed a vibration when in '2 cylinder mode'. My drive to work is just over an hour long covering 37 miles at a rather slow pace behind lorries etc 40-50mph and I am frequently in '2 cylinder mode', hence why I bought this model over the diesels I usually go for, I must add that I regularly see 50-52mpg on the dash. At first I thought it was S-Tronic gearbox because the vibration is most noticeable at 1900-200 rpm just when it wants to change gear, but after extensive playing with different scenario, gears, throttle response, dynamic modes on my mundane commute etc, I found that the vibration is totally down to a light engine load while in '2 cylinder mode' and in any gear up to 2000 rpm, anything above and it smooths out!.

I took the car back to the dealer last week and he said he hasn't seen any problems with this engine and was amazed how much vibration could be felt back through the steering wheel and pedals during the diagnostic test drive, and described it as an 'aggressive' vibration!. The service department rang me a couple of days later to say they sent off a technical query to Audi and it came back as no known fault!!! The next stage is for the dealer to have my car in for a few days and see if they can find anything?

TBC

 

[glospete]

I hear what all you guys are saying but so far (in 3000 miles) I haven't experienced any vibrations when in 2-cylinder mode - in fact this engine is one of the smoothest I have experienced! I will continue to monitor it but it is very strange.

I'm sure no bearing on this but I always use Premium fuel (and please someone don't come back and start THAT debate again). I'm happy to pay the extra so that's an end to it

 

[cuke2u]

Me too, no vibrations what so ever through the steering wheel or the pedals. In fact I would say this is the smoothest and quietest engine I have ever had. Also all the road tests I've read state that two cylinder mode is inditectable. I use cheap supermarket fuel, and no, I don't want to rekindle the debate either...

 

[cilurnum]

I'm sure that audi has done their work and tested.

Dream on. History teaches us that if you're an early adopter of these engines then you are doing the testing.

The auto media seems to be cooing over this CoD engine but I have never, ever seen a direct injection petrol that didn't develop problems around or just outside its warranty. Never seen a good one and they have historically had cylinder problems. Synchronising and shutting down cylinders is not a trivial task, and remember, you're putting all of the work on two cylinders rather than four under certain circumstances. This just sounds like a recipe for a box of spanners at some point.

 

[cilurnum]

I'm sure no bearing on this but I always use Premium fuel (and please someone don't come back and start THAT debate again).

As you should be, and I certainly would with this engine......

 

[cuke2u]

Let's not start another debate upon the myths of premium fuel please. It has been done to death...

 

[Broken Byzan]

Let's not start another debate upon the myths of premium fuel please. It has been done to death...

Myths. ..? They are facts. However back on topic

 

[cilurnum]

Myths. ..? They are facts. However back on topic

Indeed so.

The simple fact is that forums more knowledgeable than this one have picked apart the problems that VW TFSI, and various other DI petrol engines, have had with cylinder and knocking problems. These problems came out of the woodwork after some time and you don't need to be terribly suspicious to wonder what cylinder shutdown will do to the mix. These are small compression engines under considerably higher pressure than normally aspirated engines from the past. You don't get stuff for free. I would simply be running these engines on the best anti-knock fuel I could. The issues are still there but they should be healthy for a long time. As simple as that.

That may or may not have a bearing on these issues, but they sound awfully familiar to the sorts of initial gremlins that have crawled out of the woodwork before.

 

[glospete]

OK come on guys - the pros and cons of the COD engine has been done to death on an earlier thread. There is nothing new to add so let's get the thread back on topic - vibrations.

 

[dkpeter]

Been at Audi today for the engine software update and winter tyre change. It all took close to 1.5 hour. The bad news is that I haven't got any update code but the good news is that the trip home went fine without the usual vibration. I need more time to evaluate but first impressions is positive.
I am to provide feedback to Audi about the effect of the update so perhaps it is still in a testing fase.

 

[LuisM]

I'm glad to hear that, dkpeter! However, take into account that the ECU memory may have been rebooted in the updating process. I hear that the ECU learns your driving style and adapts some parameters, so it might be that the engine behaviour changes as days pass. Anyway, the fact that you didn't have vibrations on the trip back is good news. Please inform in a few days how it's going. I really appreciate your information. Thanks for all the reporting so far!

Also, in a previous post you said the vibrations are (were) more pronounced just before the system decides to go from activation of 2-cyl mode to deactivation (the same happens to me). Now that you don't have the vibrations, is it because the engine is not in 2-cyl mode in those situations when it used to be in 2-cyl in the past? Or is it still in 2-cyl but just doesn't vibrate? Have you noticed any change in the 2-cyl / 4-cyl activation pattern?

Been at Audi today for the engine software update and winter tyre change. It all took close to 1.5 hour. The bad news is that I haven't got any update code but the good news is that the trip home went fine without the usual vibration. I need more time to evaluate but first impressions is positive.
I am to provide feedback to Audi about the effect of the update so perhaps it is still in a testing fase.