I revert to the original topic of this thread: the 1.5 TSi engine cutting out when the car is in motion, usually while changing gear or slowing down at a junction, and then refusing to re-start.  The effect is total loss of power and a resulting situation that is often dangerous. If you are lucky, the car may still have enough momentum to bump-start it.  If you are unlucky, you come to a standstill in the middle of a busy junction, repeatedly getting a dashboard message to use the start button, but finding that the engine repeatedly cuts out again immediately after it re-starts.

 

To avoid repeating a fuller description of the problem, I refer to my post (above) of 11 January.  I set out there, with reasons, why this is not about an operation of a correctly-functioning stop-start system.  It is not about coasting mode (on those cars that have it). It is not about some difference between DSGs and manuals, as both have suffered from it.   It is not about stalling.  It is not about 95 versus 98 octane.  It is not about driver error or driving style.  When the engine cuts out, it cannot be re-started by dipping the clutch, or releasing the clutch, or touching the throttle.  It is a fault in the engine management system allowing the revs to drop too low and then refusing to allow a re-start.

 

I described my attempt to tackle this problem by 'Italian tune-up', as thamestrader aptly called it: that is, working the engine very hard for a while.  It has been sixty days now since I first tried it, and I've repeated it a couple of times since. This is a report on what happened.

 

Before the Italian tune-up, our 2023 Karoq Sportline was cutting out every day or two. Since then, in sixty days, it has cut out once while in Normal driving mode and zero times while in Sport mode.  So for us, the problem has gone away, after being a serious and dangerous nuisance.

 

I say 'for us' because I do not promise others will have the same results.  A trial with a sample size of 1 is not science but anecdote.  Correlation is not causation: I am not in a position to prove a causal connection, only to report on the correlation.  As I now do: I did the Italian tune up, and subsequently, for whatever reason, the problem has almost completely gone away.

 

1 hour ago, mumpsim said:

I revert to the original topic of this thread: the 1.5 TSi engine cutting out when the car is in motion, usually while changing gear or slowing down at a junction, and then refusing to re-start.  The effect is total loss of power and a resulting situation that is often dangerous. If you are lucky, the car may still have enough momentum to bump-start it.  If you are unlucky, you come to a standstill in the middle of a busy junction, repeatedly getting a dashboard message to use the start button, but finding that the engine repeatedly cuts out again immediately after it re-starts.

 

To avoid repeating a fuller description of the problem, I refer to my post (above) of 11 January.  I set out there, with reasons, why this is not about an operation of a correctly-functioning stop-start system.  It is not about coasting mode (on those cars that have it). It is not about some difference between DSGs and manuals, as both have suffered from it.   It is not about stalling.  It is not about 95 versus 98 octane.  It is not about driver error or driving style.  When the engine cuts out, it cannot be re-started by dipping the clutch, or releasing the clutch, or touching the throttle.  It is a fault in the engine management system allowing the revs to drop too low and then refusing to allow a re-start.

 

I described my attempt to tackle this problem by 'Italian tune-up', as thamestrader aptly called it: that is, working the engine very hard for a while.  It has been sixty days now since I first tried it, and I've repeated it a couple of times since. This is a report on what happened.

 

Before the Italian tune-up, our 2023 Karoq Sportline was cutting out every day or two. Since then, in sixty days, it has cut out once while in Normal driving mode and zero times while in Sport mode.  So for us, the problem has gone away, after being a serious and dangerous nuisance.

 

I say 'for us' because I do not promise others will have the same results.  A trial with a sample size of 1 is not science but anecdote.  Correlation is not causation: I am not in a position to prove a causal connection, only to report on the correlation.  As I now do: I did the Italian tune up, and subsequently, for whatever reason, the problem has almost completely gone away.

 

Thats rather interesting, which makes me wonder if the cause might be related to carbon build up in gently driven vehicles, the 'Italian tune up' gets the engine hotter and burns off or prevents the build up. perhaps when driven gently the 1.5tsi  has a tendency to run slightly rich so things get sooty. 

Yes, Missph. My 24 plate Octavia 1.5 has often stalled at low speeds, from new in January 2025. Dealer had a good look at this and found no error codes, so no problem (!). Only there is..My driving style was rightly noted for pulling engine revs below 1000 when slowing through the gears, but replication just wouldn't happen on a test drive.

More worrying still are the stalls/ cut outs when in neutral between gears. A manual restart is always required so it's not exactly like Start-stop. While Skoda have listened respectfully they have said nothing and offered no solutions, but they are surely very aware of this problem. It is dangerous and often scary.

Since around September there's been some improvement and the engine will also bump start where previously it would not. I ask if an update could have landed in the computer? I'll never know.

9 hours ago, B42 said:

Only there is..My driving style was rightly noted for pulling engine revs below 1000 when slowing through the gears,

I have the same problem. (1.5 manual 2024 KAroq)

I think it is driving style ingrained from over 40 years in conventional cars that are not stop/start

2 hours ago, chills said:

I think it is driving style ingrained from over 40 years in conventional cars that are not stop/start

Altering driving style can help some people to work around the fault. But I resist the idea that the fault is with the driver or the driving style. It's with the car.

24 minutes ago, mumpsim said:

Altering driving style can help some people to work around the fault. But I resist the idea that the fault is with the driver or the driving style. It's with the car.

I don't know enough, on this particular point, to argue either way. However, your point is quite feasible and VAG could just ignore the problem if it is not clear how to solve it, or the problem doesn't warrant, in their view, the man-hours to fix it. Now I am retired, I don't get to the conferences I used to so I can have a quiet informal word with the right people. :-(

Edited 8 December, 20258 Dec by chills

I note a couple of replies above mention the engine cutting out approaching a junction as the gearbox goes through neutral. Now I know my 2,0 TSI DSG is not the same at all, but it can do something very similar and I wonder if this is what is also happening on the 1.5 TSI. If I am slowing down, typically when turning right from a central right turn lane with very light brake pressure, i.e not enough to bring the car to a complete standstill though, at about 3 mph the revs drop to zero but the moment I release the brake pedal the engine restarts.

I think this is the Stop/Start system cutting the engine as it (wrongly) assumes the car is coming to a complete stop.

Has anyone had this cutting out happen when stop start is disabled?

18 minutes ago, thamestrader said:

I think this is the Stop/Start system cutting the engine as it (wrongly) assumes the car is coming to a complete stop.

That is what I think. For me, it can happen several times in a row on a short local trip and then not for weeks.
I think it is part driving style, and only happens in a few circumstances, so VAG can't be bothered to do a lot of work to fix a "minor" intermittent problem.

My previous car had exactly the same transmission but both my wife and I experienced no such issues. It gets probably more of an " Italian tune up" than the previous model as it's a Sportline. I agree that it points to a start/stop issue. I'm hoping for a simple fix like a software update 🤞🏼🙄

What is most concerning is that VW do not seem to acknowledge the problem when it has been reported right across their range for several years now.

A previous post suggested that the complex nature of the engine could be the answer so that a slight maladjustment causes the stall. This could be why only some owners experience the problem.

It has happened to me on several occasions but the worst aspect is that it is completely unpredictable so can give rise to frightenining scenarios.

The Karoq will be my last VW group car.

1 hour ago, thamestrader said:

Has anyone had this cutting out happen when stop start is disabled?

Plenty of people (including me) have reported that they still get cutting-out when stop-start is disabled. That's with the manual gearbox.

Cutting-out also happens to people with the DSG, though far fewer have reported that, and most find the DSG car will re-start by pressing the throttle pedal, which certainly can't be done with the manual.

So far as I know, nobody who has experienced cutting-out with a DSG has said whether or not disabling stop-start has had any effect.

As I said in some earlier post, the stop-start system may or may not be implicated in this fault, but if so, it is an incorrect (faulty) operation of that system. Or some other system!

1 hour ago, Karock said:

A previous post suggested that the complex nature of the engine could be the answer so that a slight maladjustment causes the stall. This could be why only some owners experience the problem.

A mix of individual car settings and condition coupled with driving style could either raise or lower the occurrences.
A difficult thing for VAG to sort out easily I susspect.

16 hours ago, mumpsim said:

Cutting-out also happens to people with the DSG, though far fewer have reported that, and most find the DSG car will re-start by pressing the throttle pedal, which certainly can't be done with the manual.

I have not had this problem. On my 2018 1.5 DSG when stop start cuts the engine a twitch of the steering wheel restarts it, perhaps this is a factor to consider.

tom

I have a skoda octavia tsi 2025 the car engine has cut out a few times the worst was on a roundabout going slow, start stop was switched off when i put my foot on the clutch and touched the accelerator the car started up again.

My 2024 Octavia has now been back to the dealer multiple times for this exact issue, most recently for a three-week period of diagnosis and road testing with Skoda technical involved after we rejected the vehicle. Skoda have emailed the dealer to say the issue is caused by the engine ECU shutting down the engine in order to protect the dual mass flywheel when it detects a potential stall condition at low RPM. So it's working as designed and there is no fault. Their official guidance is to modify your driving style to avoid low RPM in higher gears. I have searched through the user manual and on Skoda's website but can find no mention of this. Learner drivers have been taught the "brakes to slow, gears to go" mantra and to use block gear changes for decades (as per DVSA guidance), so for VW Group to tell us otherwise is astonishing. I have kept a detailed log of incidents and I will now be submitting a report to DVSA.

8 hours ago, Sassenach said:

My 2024 Octavia has now been back to the dealer multiple times for this exact issue, most recently for a three-week period of diagnosis and road testing with Skoda technical involved after we rejected the vehicle. Skoda have emailed the dealer to say the issue is caused by the engine ECU shutting down the engine in order to protect the dual mass flywheel when it detects a potential stall condition at low RPM. So it's working as designed and there is no fault. Their official guidance is to modify your driving style to avoid low RPM in higher gears. I have searched through the user manual and on Skoda's website but can find no mention of this. Learner drivers have been taught the "brakes to slow, gears to go" mantra and to use block gear changes for decades (as per DVSA guidance), so for VW Group to tell us otherwise is astonishing. I have kept a detailed log of incidents and I will now be submitting a report to DVSA.

Well done for persisting with this and not being fobbed off as so many people have been (including me). It is a victory to have got Skoda to admit to the cause of the problem. Let's hope DVSA will recognise it is a real safety issue. Let us know if there is any benefit in getting several people to back up your story to DVSA.