ACT vibrations on the Octavia Combi 1,5 TSI DSG7

[GKE]

Am I the only one experiencing vibrations in the whole car when it drives in 2-cyl mode?

My Octavia from Oct 2017 (brand new, 2018 FL model) is equiped with the ACT (active cylinder technology) and shuffles btw. 2- and 4 cylinder modes as needed.

Going downhill the 2-cyl drive is COMPLETELY un-noticable. But it shure is not when there is the slightest load applied. The system switches back to 4-cyl when the load is to high - but in my opinion it should be way sooner, or the system should work more seamless as advertised...

 

I hate cruising 70-80 km/h in 6th or 7th gear and feeling the whole car vibrating under me...

 

Any experiences anyone? I see many threads about this on VW forums, but can hardly find anything on Skoda's.

Would appreciate any help reg. above.

[YMe]

This sounds like a warranty job; my 1.5TSi DSG is as smooth as silk in 2 cylinder mode, coasting and under load.

[Orville]

Maybe a loose engine mount?

[Gerrycan]

1 hour ago, GKE said:

 

Any experiences anyone? I see many threads about this on VW forums, but can hardly find anything on Skoda's.

 

The 1.5tsi has only been available for a short while in the UK on the Octavia so there are not yet many active users 

I watch the Briskoda Superb section that has the ACT 1.4tsi and there has never been anything similar mentioned there

The reviews I have read of this engine are all glowing about the ACT transition.

What rpm are you doing at 70 to 80 kph in 6th/7th?

 

I used to have a carby based Austin that transitioned to 3 cylinder mode once and that was pretty rough.

 

Edited 30 January, 2018 by Gerrycan

[SoupDragon]

My 1.5 ACT is good. You would not know it was operative if the display did not show it. In 5th or 6th, about 40 mph plus, the fuel consumption falls away but the engine note and any vibration does not change. However, I would not floor the pedal when in 2 cylinder mode, I would change down a gear or two if I needed to accelerate hard. The engine always returns to normal mode very quickly. Mind, I am driving the car gently because it is very new.

[GKE]

8 hours ago, Gerrycan said:

What rpm are you doing at 70 to 80 kph in 6th/7th?

 

The car usually prefers 6th gear during the 70kph - about 1800 rpm I would.

When closing in on the 2000 rpm and approx 80 kph it shifts to 7th. That part of is quite comfortable - the shifts are OK. It's the ACT vibrations that irritate me. 

 

On a silk-smooth road surface, I sometimes find myself manually shifting up to 7th gear to drop the RPM under the ACT operating range, just to avoid it... ACT de-activates around 1400 rpm.

I am glad you guys are happy about it - I just hope Skoda DK can come up with a solution for mine too...

 

I contacted them a few weeks back, and they didn't really know what to do. They mentioned that the Polo GT had the same issue, but it was SW fiixed. 

However, they are NOT allowed to use VW SW on Skoda cars for some reason... argumenting it with vehicle configurations etc...

 

Is there any chance that you guys with perfectly smooth ACT can check your SW versions? I have no idea how that is done... But perhaps I can push the dealer to upgrade to a specific version

[fergiet]

Only had ours a few weeks and only at 700 mls but not been aware of any such issue. I assume it's in 2 cyl mode when the "ECO" symbol shows on the dash ?

 

 

 

[YMe]

6 minutes ago, fergiet said:

Only had ours a few weeks and only at 700 mls but not been aware of any such issue. I assume it's in 2 cyl mode when the "ECO" symbol shows on the dash ?

 

 

 

Yes it is but you are not in 2 cylinder mode when you are coasting (speedo needle showing idling revs).

 

If you set your maxi-dot to show average consumption it tells you when you are in 2 cylinder mode.

[cr_2dman]

When you drive 50 / 70, you put up the cruise control, the ECO sign appears (or 2 cyl) and wait for around 2-3 seconds, the buffeting starts (like an open window ?)

 

[GKE]

Yes very much so - only it appears almost instantly when ECO sign is on, and is absolutely worse about 2.000 rpm - all depending on engine load.

I've had a couple of engine sw upgrades from Skoda that seemingly have shifted the buffeting a bit. It's like the load needed to de-activate ECO is a bit lower, hence running a more often on 4 cyls.

Now i'm no longer (that much) bothered, unless i'm on the highway (speed limit hits 2.000 rpm exactly) or i'm driving in S-mode, which also buffs the revs up. 

 

Shi*ty ACT implementation i must say... VW Passat with same engines seems to have none of these symptoms i've heard.

Skoda even tried chassis adaptations to minimize the vibrations/buffeting but with no luck. (Bitumen plates on engine cover, tweaking hatch door hinges, etc.) 

Edited 9 May, 2019 by GKE