Octavia nose dives on pullaway

[BigKev2]

Earlier this year I started a thread regarding the over revving feature that Skoda fitted , called pull away assist. This annoying feature raised the revs to 1800 when you lifted the clutch in first gear. After a campaign with Skoda they reduced the severity of this feature with a software update.

Now I have another issue that I am going to take up with Skoda. The car nose dives when pulling away. Its as though the throttle is not responding to your foot. I have tried to work round this issue but just cant get consistent smooth pullaways. So before I go back to my dealer I would like to hear of others  experiences when pulling away. My car is a 2018 Octavia 1.5 TSi 

[SoupDragon]

Just the same BigK. I had the software update which stops the unwanted rev. rise but has left the poor throttle response you describe. After 4 months, I still can not make a reliably smooth takeoff and still occasionally stall the engine. To guard against stalling, I use higher revs than necessary but even then it feels like the engine completely dies as you release the clutch. There does seem to be an exceptionally long gas pedal movement. I can not tell if the uncertainty is caused by imprecise gas pedal detection or if the ecu is sometimes rather slow to detect the gas pedal movement. I wonder if the original rev. rise issue was an attempt to overcome the pedal detection problem. My car is same as yours.

[BigKev2]

Thanks SD. Oh this seems familiar dosnt it, here we go again. After Pullaway saga I just wanted to have  a breathing space and hoped I would settle into nose diving. Called to see my mate a couple of days ago to see how he liked his new Octavia and without prompting he said, great car, but it nose dives. Arrrgghh. That set me off again. That's all I needed to re awaken grumpy old man .

So I fear its back to see Mr Skoda dealer. I believe there is a mod you can do to fix this issue. It is to fit a thing called a DTUK pedal box. We should not have to do this but if anyone has fitted one to their 1.5TSi Skoda I am interested to hear about it, ie how much, where from, how it fits.  

[krjh]

Interesting to read this is a "feature"!  My new 1.5 TSI was delivered a week ago and I've experienced the nose dive a few times already.  I'd stumbled across (like you have to with many things given how bad the user manual is) the automatic rev increase when releasing the clutch in 1st gear and was suspecting that the issue is a poor handover from this auto rev control to manual rev control based on throttle pedal position.  The circumstances of it happening will maybe gradually become clearer, or maybe I'll learn to drive round it, but I'll be interested to hear of a better fix if one is found.

[RoscoPColtrane]

The only time I experience the nose dive is a few hundred yards from home where there is a left turn that sweeps onto the road I live on.  You don't usually need to stop there so I am going at about 10mph just in case there is something coming.  If I don't need to stop and then I accelerate, the car seems to hesitate and I get the nose dive effect.  I have never had it anywhere else, but it always occurs in that one place.  I have a similar story with the increased revs, I thought for the first day or two that my car didn't have this issue, but occasionally when reversing it does increase to the 1800rpm mentioned.  I've also experienced it a couple of times in stop-start traffic, but very rarely (and I sit in a fair amount of stop-start traffic...). To stop it I just dip the clutch for a second and then it's fine.  I will get the update when the car next goes to the dealer but it hasn't been enough of an issue to warrant a special trip.

 

What I have noticed though is how much the throttle isn't very progressive.  I seem to get the same response from the engine by pressing the accelerator a little way or half way, then after that there's more power.   It seems better in sport mode, but that might just be my imagination, though I think I read in the manual that the throttle response is a bit sharper in 'sport'.  Maybe this lack of progressive response is linked to the nose diving mentioned?

[SoupDragon]

I set the gas pedal into sport mode soon after I got the car and hoped for a bit more response but it made no difference at all. The throttle pedal response is very very slow and unpredictable. I find that I often have to modulate the clutch and gas controls maybe three times as I try to get a smooth getaway. It leads to loss of confidence about what is going to happen when you enter a roundabout etc. It's like a very old car when the carburettor is worn out.

[just music]

Same here, and I also sense that it's underfueling when coming on the gas after a period of steady progress, esp in 2nd or 3rd. There's just a moment of hesitation.

Let's hope you continue your magic touch in getting the software sorted! 

Out of interest, what idle speed do people have following the update? Mine is around 950 rpm which seems a bit high. I've turned off the AC to make sure it's not just  compensating for the load.

 

This engine certainly does not feel as strong as the 1.4. That would pull so well in high gears, but the 1.5 needs lower gears generally. I also think mpg isn't as good, but I haven't yet done a sensibly long journey to test and compare it, and of course the car's only done 1200 miles. 

[vegit8]

Yep 

Same tale as above.

Had the software update to stop the stall prevention assistant overrevving the engine when lifting the clutch on pullaway.

 

Had nose dive assist as well. Its very effective. 

Purchased a DTUK pedal box now I get nose diving very very rarely, usually when short shifting between 1 and 2.

Running Pedal box on city mode +1, the car is now much more responsive and drives like I hoped it would.

Its not cheap but it does make a big difference, easy to fit. Most importantly does no affect insurance.

Here is the FAQ - link

[SashaGrace]

Has anyone with a 1.5 TSi suffering with this issue had the car on VCDS or OBDEleven? I ask ask you can change the throttle control to direct control instead of the factory indirect control. I wonder if that’s something that couldn’t help. It made my TDi quicker to pick up instead of suffering from its flat spot between 1000-1200 revs

[mumphie]

2 minutes ago, SashaGrace said:

Has anyone with a 1.5 TSi suffering with this issue had the car on VCDS or OBDEleven? I ask ask you can change the throttle control to direct control instead of the factory indirect control. I wonder if that’s something that couldn’t help. It made my TDi quicker to pick up instead of suffering from its flat spot between 1000-1200 revs

 

Was just going to say the same thing!

[AlexBlue]

Interesting topic considering I'm collecting mine in a couple of weeks. If I had a choice would it be better to have the nose diving over the over revving?

 

And with the overrevving, does pulling away in 2nd make it any better? Assuming you're not trying to drive it like you stole it, of course.

I'll stay subscribed to this thread, it's a new engine for the octavia, I was in two minds over a new 1.5 or a new forecourt 1.4, with my original doubt on the 1.5 with the ACT, but I have accepted this having been in use in other engines for a couple of years now. I'm really going I haven't made a bad mistake with a significant amount of cash (was planning to buy outright and keep it long term)!

[BigKev2]

You don't have a choice. The car has two issues:

As soon as you lift the clutch pedal when in gear a switch tells the brain to rev the engine to approx. 1800rpm. This is before the clutch bites. Your wife will comment, 'you seem to rev this car a lot'. This will drive you mad and the dealer can do a software mod that will tone down this 'Pull away assist' so that it only revs to 1000 from an 800 idle. You will be able to live with that. Before you get the car ask them to do software update - they wont unless you ask (my view)

The second issue is the nosedive which seems to have nothing to do with the Pull Away Assist and I like the term Nose Dive Assist. Over revving, 9/10 for annoyance, Nosedive, 4/10. I have yet to start my campaign with Skoda to sort the nosedive, I ride my motorcycle instead. 

The trick with the 1.5TSI is don't stop, keep moving at all times then it really is a lovely car. The nose dive does however give you the satisfaction of watching wifes  head rock forward, revenge for her over revving comments.

[Octy0GG]

1.5TSI sounds pretty grim but would have to say that, while it might not be so bad, from my experience the 1.4TSI (Euro 6) throttle response is not exactly brilliant in it either, with occasional nose dive assist thrown in.

 

It just seems bizarre that after all the years of fuel injection and turbo development aimed at reducing flat spots, surges and lag they are now developing engine management software to reintroduce them. 

[AlexBlue]

2 hours ago, BigKev2 said:

You don't have a choice. The car has two issues:

As soon as you lift the clutch pedal when in gear a switch tells the brain to rev the engine to approx. 1800rpm. This is before the clutch bites. Your wife will comment, 'you seem to rev this car a lot'. This will drive you mad and the dealer can do a software mod that will tone down this 'Pull away assist' so that it only revs to 1000 from an 800 idle. You will be able to live with that. Before you get the car ask them to do software update - they wont unless you ask (my view)

The second issue is the nosedive which seems to have nothing to do with the Pull Away Assist and I like the term Nose Dive Assist. Over revving, 9/10 for annoyance, Nosedive, 4/10. I have yet to start my campaign with Skoda to sort the nosedive, I ride my motorcycle instead. 

The trick with the 1.5TSI is don't stop, keep moving at all times then it really is a lovely car. The nose dive does however give you the satisfaction of watching wifes  head rock forward, revenge for her over revving comments.

Ah, my misunderstanding, I thought by fixing one, the other occurs or gets worse. Yay, two separate issues! I'll be speaking to my sales guy this week and will mention this to him (I saw the field code/number whatsamajig on another thread for the overrevving.).  And never go slower than 5.5mph ;-)

[Nescafe1]

Is this isssue limited to the 1.5 tsi manual or does the 1.5 tsi DSG also suffer these isssues as I’m due to pick up a 1.5 tsi DSG in a couple of months and didn’t notice anything on the one I had my test drive in?

[nidza]

Sounds like a lazy turbo spool how you're all describing it. Whoever designed this particular engine probably has noticed some numbers aren't right, so you had before ECU reving engine to much to correct them. Now when someone else figured out it is not normal that you start up with 1800 rpm (good morning Columbus), initial issue has been reintroduced. 

 

I only wonder if another software update can solve both issues? 

If I understood properly, the issue is only on start up, during normal drive all is fine? 

 

How the car pulls if you drive constantly at, for example, 1200-1300rpm, and you press the throttle? Does it hesitate? Is there a difference if you press throttle all the way immediately, or you gently progress through the range? I have learned always to press the throttle gently, a habit from a carburetor time, even when I needed a full throttle.

Edited 26 June, 2018 by nidza

[Gabbo]

Its difficult to understand this without experiencing it but but to me it sounds more like torque limitation in 1st gear which is also present sometimes even on the vRS TDi.

As Sasha suggests it would be good to see if the modification in VCDS to take the real pedal value improves this problem.

 

You think you have a lot of travel left in the pedal but for the ECU you have reached the maximum & it feels like the engine power is gone completely as you press further.

It reality its just that the Accelerator is constant rather than increasing as you'd expect.

 

For me the main problem these days with electronic Accelerator pedals is that most manufacturers try to fool you into thinking their car is "nippy" by artificially modifying the Accelerator pedal behavior so on a small engine 40% pedal travel = 100% torque.

Its the same on my vRS & I think is also the main reason why many drivers complain they cant achieve good fuel economy because even slight pedal modifications give big torque requests to the engine.

[BigKev2]

Just back from doing some pull away tests in Tesco car park. I wanted to get more info on when and how the nose dive occurs.

It occurs when pulling away in first gear before the clutch is fully released. I can defeat the nose dive if I slip the clutch more using high revs. I can also defeat it if I do a  clutch lift with hardly any revs and then put the revs on once the clutch is fully released. 

I then tried crawling in first gear at tickover speed with clutch fully released. Applying the throttle slowly or fast the car moved smoothly forward with no nose dive.

So I believe the clutch position is a factor in the fuelling. I know that the clutch position is the trigger for the over revving on pull away. The trigger point for the rev increase is just off the floor but not yet at bite point. It seems to me that there is another clutch position near the fully released that is involved in the nosedive.

For the record I am getting 53mpg long term average and the car drives so smoothly (apart from pullaway) - 1.5 TSI.

 

[ettlz]

On 26/06/2018 at 10:49, nidza said:

Sounds like a lazy turbo spool how you're all describing it. Whoever designed this particular engine probably has noticed some numbers aren't right, so you had before ECU reving engine to much to correct them. Now when someone else figured out it is not normal that you start up with 1800 rpm (good morning Columbus), initial issue has been reintroduced.

 

These engines should have plenty of torque for a smooth pullaway below 1800rpm. My 1.2 TSI (Fabia) will move off quite rapidly on just the clutch after a subathed cold start, whereupon it idles at 1200-1300rpm. But for some reason, once it settles it will not let me command the same engine speed to move off -- if I set the gas to anything above idle, as I raise the clutch pedal it'll add another 500rpm that's simply not needed.

 

I suspect the 'nose dive' effect is a result of the 'take-off assist' stopping at 2-3mph. This is why things are smooth when you're already rolling (and there's not so much psychological pressure to get that God-awful gas pedal right). The sequence of events is:

1. Set the gas to something appropriate for pulling away.
2. Bring the clutch up. Just before the biting point, the ECU decides to give you even more revs (so wife asks questions, Senior Observer gives a funny look...).
3. Clutch begins to engage, car starts rolling, quickly hits 2-3 mph.
4. At this point, the ECU thinks: OK, we're going now, clutch almost up, revs matched, cut rev boost to save fuel BUT DON'T TELL THE HUMAN TEE HEE HEE!
5. Human continues to let clutch up, right foot stationary (because it's already revving!) but because the ECU has dialled back to somewhere just above idle you get the nosedive.

On my 1.2 to get this "nicely" smooth I have to remember to apply more gas pedal progressively as the car takes off to counteract the effect of step 4 above. It's a pain in the arse because it's a pedal with a soft spring, next to no friction, and very precise position metering. Humans shake. Add to that the stupid big idle zone at the top, about 5% of the total travel: the ECU sees all pedal movement in this zone, it just chooses to ignore it until it reaches a certain threshold.

 

VAG, what the hell? Do they think we can't drive properly?

 

I guess either they're trying to engineer around dodgy driving practices (contrary to good DVSA style, which I believe is to set the gas, and then let out the clutch -- besides I hate manoeuvring on idle), or they're trying to get up some boost pressure so that it feels more sprightly/eliminates turbo lag once you've got the clutch fully engaged. However I don't always want to go like a dead bird off a shovel.

 

It's about time the EU mandated all car control units' source codes be made public.

Edited 27 June, 2018 by ettlz

[BigKev2]

ettiz - what a great post. You explain perfectly a situation that drives me mad. Every time I pull away I try to beat the bas-ard but it normally wins. I never considered that it may be intervening based on speed.

Its  sad that we are so technically advanced now and yet we could pull away better 40 years ago. I am an engineer so I feel I need to persue this crap. On the other hand I am 65 and wonder if I can be bothered. I badgered and badgered to get the rev assist moderated but not sure I can go through it again. Her indoors with all her technical know how  is loving it, 'I told you Skodas are sh-t'.

[nidza]

So lucky vRS is not doing any interventions. TDI is raising rpms a little when you press and release the clutch so you can smoothly maneuver on slow speeds and parking, so you can have your right foot always on the brake pedal, and left one on the clutch. Throttle does not need to be engaged at all.

 

Has  anyone tried to start gently without a throttle, just on idle rpms? 

[Gabbo]

The same pullaway assist & anti-stall functions are available on all engines it just seems like whoever calibrated the 1.5 did a really bad job with everything.

Agree with Nidza though that a diesel is much easier to pullaway than a petrol as theres enough torque to drive away without even touching the Accelerator pedal.

 

However, with modern electronically controlled throttle, injection & spark on a petrol engine there should also be no need to rev the engine before moving the clutch.

The ecu can compensate where necessary.

 

BigKev, I hate to say it but it seems you should have a word with your garage again.

Maybe you can offer your services as a drivabilty engineer for VAG, you're obviously doing a better job than the 1.5 team...

[ettlz]

13 hours ago, BigKev2 said:

Its  sad that we are so technically advanced now and yet we could pull away better 40 years ago. I am an engineer so I feel I need to persue this crap. On the other hand I am 65 and wonder if I can be bothered. I badgered and badgered to get the rev assist moderated but not sure I can go through it again.

 

You and I are probably unfashionably old-school when it comes to car control, inasmuch as we expect a manual to be just that: predictable, with a linear control law that uses the whole pedal travel. Not laden with dubious, half-baked 'driver assistance' software gizmos that defeat all intuition.

 

Anti-stall/rev boosters are completely unneccesary with correct pedal control. These things encourage lazy habits and seem to exist only to soothe the egos of millennials who can't drive properly.

Edited 28 June, 2018 by ettlz

[Rodge]

15 hours ago, nidza said:

Has  anyone tried to start gently without a throttle, just on idle rpms? 

I do it all the time in slow moving traffic in both the Octavia and my 2003 1.6 l Focus.

[BigKev2]

Its been quite a while since anyone posted on this thread. I have been trying to live with the nose dive without success and have even started to buy magazines and look at another car. However I have decided that first I will go back to the dealer and discuss it. So before I do, has anyone (like me) had the over revving sorted and has then  been back to the dealer to see about the nose dive.