Engine revs without foot on accelarator

[BigKev2]

Hi

New to the Forum today so apologies if this subject has already been covered somewhere.

I have a two week old Octavia 1.5 TSI SEL. When pulling away as soon as the clutch leaves the floor the engine revs increase from 800 to between 1400 and 1800.This is without any pressure on the accelerator. The car is back at the dealers now to have this checked out but the Technician I spoke to said that's what is supposed to happen. He reckons its an anti stall feature to make sure you have enough revs to pull away. I find its a pain. The Tech said the trick is to change how you drive, ie instead of feel for clutch bite then put revs on, put revs on as you lift clutch pedal. If the tech is right then crawling in traffic will be  pain and will put more wear on the clutch Any info guys ??

[DaveLees]

 

I have a similar issue with my 1.5tsi with the revs going up to 1800-2000 when the clutch is released. It's interesting to hear what the technician says, it's a pain, especially when reversing into a parking space or if in slow moving traffic, it does make it sound as if you can't drive and are slipping the clutch. I have a very slight downhill gradient to park on the level, it means that as I ease the clutch out onto the level the revs increase to around 2000!

This topic was brought up a week or so ago by someone else with  1.5tsi so it seems to be an issue with this engine.

[BigKev2]

The revs are higher when the engine is hot. Pulling away cold the revs only climb to say 1200. When hot they reach 1800 just as the clutch is lifted. A you say it sounds like you don't know how to drive. In fact my wife said you seem to rev this car a lot !!  This is a feature that is not needed. I am interested to see what they do to the car today at the dealers. I fear the clutch is doing more work than it needs to. 

[DaveLees]

6 minutes ago, BigKev2 said:

The revs are higher when the engine is hot. Pulling away cold the revs only climb to say 1200. When hot they reach 1800 just as the clutch is lifted. A you say it sounds like you don't know how to drive. In fact my wife said you seem to rev this car a lot !!  This is a feature that is not needed. I am interested to see what they do to the car today at the dealers. I fear the clutch is doing more work than it needs to. 

I'll be very interested to hear what they do at the dealers today.

Which dealer is it?

[BigKev2]

Its Pullmans Durham. If the revs bumped up tp say 1000 it would be OK, but 1800 is just clutch wear. I am hoping that they will have either removed the feature or calmed it down. When cold the car also dosnt feel right at low speed, like its hesitant. I will post what happens. 

[DaveLees]

21 minutes ago, BigKev2 said:

Its Pullmans Durham. If the revs bumped up tp say 1000 it would be OK, but 1800 is just clutch wear. I am hoping that they will have either removed the feature or calmed it down. When cold the car also dosnt feel right at low speed, like its hesitant. I will post what happens. 

Okay thanks. Mine is from Silbury, as is the other car mentioned in the previous post.......it could be the northern air!!

[Gabbo]

There is another user on the forum who raised exactly the same question recently & recieved the same answer.

 

This feature is present on all other models but the engine speed increase is limited to 1000rpm. It seems the 1.5TSi is affected by this increase to 2000rpm.

I'm sure this is not correct & there will probably be a calibration update to correct it fairly soon I would hope.

 

Whilst the feature might be useful for normal driving it will for sure be a pain when driving in stop-start & heavy traffic.

In contrast, on my car with this function increasing the revs to 1000rpm it is particularly usefulin traffic as you dont need to move your right foot to crawl along in the queue.

 

[peter_k]

Assuming I'm reading about the same engine then the  "anti stall" explanation is a little suspect.  VW say this:

The four-cylinder engine simultaneously impresses with even quieter running and a level of pulling power even from low speeds that facilitates fuel-efficient driving in high gears. The maximum torque of 200 Newton metres is available from just 1,400 rpm and remains so across the entire engine speed range up to 4,000 rpm

 

https://www.volkswagen-media-services.com/en/detailpage/-/detail/Offering-technical-refinements-new-15-TSI-delivering-96-kW130-PS-now-available-to-order-for-Golf-and-Golf-Variant/view/5403505/7a5bbec13158edd433c6630f5ac445da?p_p_auth=g0xJXYiH.

[BigKev2]

I think there may be some confusion with what is 'anti stall'

Crawling in traffic without using the right foot has always seemed possible on modern cars. I presume this is due to the ECU maintaining its target idle speed when it gets slightly loaded by 'crawling'. In the old days this was not possible as the idle speed was fixed by a screw setting on the carb and if you attempted to load the engine without any throttle it would simply stall as the fuel supply was not increased.

Skoda may well have developed a cleverer feature which ups the revs when it knows you are pulling away. This however takes away the driver control and is just annoying. 1000RPM  from an 800 idle would be OK but not up to 2000 as I have. It may just need calibrating we shall see what they say today when they say car is ready. If its 'they all do that sir' I think my response will be keep the car until you have the feature toned down or removed.

 

 

[ords]

1 hour ago, Gabbo said:

There is another user on the forum who raised exactly the same question recently & recieved the same answer.

 

This feature is present on all other models but the engine speed increase is limited to 1000rpm. It seems the 1.5TSi is affected by this increase to 2000rpm.

I'm sure this is not correct & there will probably be a calibration update to correct it fairly soon I would hope.

 

Whilst the feature might be useful for normal driving it will for sure be a pain when driving in stop-start & heavy traffic.

In contrast, on my car with this function increasing the revs to 1000rpm it is particularly usefulin traffic as you dont need to move your right foot to crawl along in the queue.

 

Even my 1.6 tdi auto only increases to 1000 rpm after releasing the brakes.

[SoupDragon]

I have posted about this annoying effect previously. My car is a 3 week old 150 Tsi ACT. The engine will sometimes rev up to about 2000rpm without any input from me when manoeuvring slowly or starting off. It doesn't depend on engine temperature or gradient. In addition to the noise, when I get going in first gear, the car sometimes surges forward and back as the revs settle. My wife has asked me if I am having trouble. I have found in addition that I can not pull away gently on the flat in first without using the accelerator which is something that I used to do. I think that the engine has no power at less than about 1100 rpm and is easily stalled. This effect combined with the quietness of the engine has led me to stalling a few times. I think the engine needs to revved harder than I am used to, maybe 1400, to be sure of not stalling and I am reluctant to do that because I think it is bad for clutch wear. Another possibility is a lightweight flywheel. On earlier cars, a touch of revs just before letting the clutch up was enough to spin up the flywheel and use its inertia to get the car rolling. My conclusion is that I do need to be a more aggressive with the gas pedal when starting, but not to rev it to 2000. I have been doing that lately and I am sure that the big surprise rev up is not happening so often. I still have the problem of slow manoeuvring though. I expect I am letting the clutch slip a little without demanding lots of revs and the effect kicks in again. This happens regularly when I am leaving or entering the drive to the house and all the neighbours can hear me. I am very interested to hear what the garage can do about effect. Good luck.

[Gabbo]

1 hour ago, BigKev2 said:

Skoda may well have developed a cleverer feature which ups the revs when it knows you are pulling away.

This is not a new or special feature, you will find it on pretty much most cars these days.

You can see the function working if you lift the clutch off the carpet but don't reach the bite point, the engine revs will increase in anticipation of driving away.

 

My previous Ford, BMW and now Skoda TDi vRS increase the RPM to around 1000 to help prevent stalling at pull-away.

 

You see the same phenomena in action when the car is moving & you dip the clutch before coming to a stand-still. The rpm is held at 1000rpm until you reach a stop & it will drop to 800.

 

Increasing to 2000rpm seems excessive especially with modern fuel injection systems.

It would be interesting to hear the reasons why it is necessary only on the 1.5tsi.

 

Maybe its worth looking in the similar VW or other Skoda forums using the same engine.

Do they complain of the same thing & what was the explaination?

 

Edited 6 February, 2018 by Gabbo

[BigKev2]

I agree with the last two posts. auto blip to1000 RPM, fine, 1800 - 2000 no thanks. I also have the same issue as Soup Dragon. When pulling away cold the 'rev' effect is not as bad as when hot, however I get jerkiness as I go from 1st to second. Its as though the car is underfuelled - like in the old days when you tried to pull away without using the choke,   aaahhhh chokes. They have had the car for 5 hours now, heard nothing yet.

[DaveLees]

SoupDragon I've just emailed Justin at Silbury to see if he is aware of this issue. It will be interesting to see what Pulmans find with BigKev2 car.

[millerhouse]

I've got a 2 litre diesel and this also happens in my car - lift my foot off & it just keeps going. Not something I can't remember happening in the Citroen I had until recently. Also with Silbury so I'll be interested in their reply.

John M

[themanwithnoaim]

2 hours ago, ords said:

Even my 1.6 tdi auto only increases to 1000 rpm after releasing the brakes.

Autos/DSG are the way forward

[DaveLees]

7 minutes ago, millerhouse said:

I've got a 2 litre diesel and this also happens in my car - lift my foot off & it just keeps going. Not something I can't remember happening in the Citroen I had until recently. Also with Silbury so I'll be interested in their reply.

John M

I think that yours may be slightly different. The 1.5tsi is increasing the revs when the clutch is released without any pressure on the accelerator.

[xman]

Welcome to the beta testing and development debugging programme.

 

We welcome feedback and will pass your concerns on to our development team 

 

 

Edited 6 February, 2018 by xman

[SoupDragon]

Dave Lees, I have just arranged to visit Silbury on Friday morning to demonstrate the effect. I hope I can make it happen.

[BigKev2]

Mine is more pronounced when hot. On a cold start the revs are high for a short while anyway , say 1000, so maybe the ECU is happy with that and dosnt bother annoying me. 

[DaveLees]

11 minutes ago, SoupDragon said:

Dave Lees, I have just arranged to visit Silbury on Friday morning to demonstrate the effect. I hope I can make it happen.

Can you let me know how you get on please?

I'm booked in for Monday 19th.

[BigKev2]

So I have now had a call back to say my car is ready.

Firstly let me say I have no issue with Pullman Skoda Durham whatsoever. Everything has been fine with them. I believe they are caught between the customer and Skoda Technical dept.

The technician has said that fault codes have been checked and the car is behaving as the other 1.5TSIs have. They say the engine revs rising when clutch is lifted is a safety feature to prevent stalling. They tried to demonstrate the same effect on another 1.5TSi but there was not one available .

After I expressed my frustration to the Technician over the phone he took the car for  a 20 min test drive and rang back again  to confirm it was as it should be. They have sent a memo to Skoda Technical detailing my issue, reply expected tomorrow.

Its worth looking at this issue in a bit of detail:

Drivers pull away without giving much thought to what they are doing - you do it without thinking. Thats the problem ! All cars have different clutch and accelerator dynamics yet you adapt instantly. This is how I think I pull away - lift clutch till you reach the bite point then slowly lift clutch while feeding in a bit of throttle. What Skoda seem to have done is spoil that. When the clutch starts to lift the eng mangt will raise engine revs if it sees no input from the throttle, ie danger of stall.. The engine revs rise  and you can pull away smoothly without touching the acc pedal. If you are not in gear and lift the clutch the revs do not move as the ECU knows you are not pulling away

If you want to take control I think you need to lightly touch the throttle fractionally BEFORE you move the clutch at all. If my theory is right the auto raise of revs will be disabled since the car sees revs are raised above idle and you  have control.

The car is still at the dealers. I am so frustrated by this, its taken the joy out of the new car. I will test it tomorrow and then discuss with the Service Manager . The more people complain the more chance we have with Skoda doing a fix.

 

 

[SoupDragon]

Thanks for the info, I am taking mine in on Friday to Silbury at Cramlington. I will let you know what they say. I have been looking through the owners manual and it shows max torque available at 1500 rpm, for the 150 ACT motor. I can see that the system makes sense in some ways. I will try your theory out.

[Octy0GG]

With my 1.4TSI being just over a year old. I'm not in the market for a car at this time, there are however enough alarm bells ringing here to convince me that this engine has undergone  inadequate prototype testing. There are explanations and a possible work around, there may even be a remedy. An official remedy would however require the acknowledgement of a problem - always difficult for VAG. Given the lack of testing I have to assume the long term reliability of the variable geometry turbo (yes, common in diesels but not in petrol engines) is similarly untested -that has to be a worry.

 

Might turn out to be a great engine but if spending my own money I'd be giving it a wide berth for a while yet.

 

Had the engine been properly tested this feature would have been sorted before they were in the hands of paying customers.

 

Plea to VAG - Please bring back prototype testing.

[Gerrycan]

The 1.5 ACT is not available yet in Australia on the Octavia or Golf and judging from the above comments that is not necessarily bad.

If this is really ' a feature', then I for one would not be interested in it as a replacement for my 1.4tsi.

 

I have a couple of questions though:

This issue initially came up in another thread and his complaint was this troublesome characteristic was at its worst when starting from cold and settled when warm, whereas most of the above in this thread seem to be saying the opposite ie not so bad cold, and worse when warm (?).

Are there 1.5tsi manual owners who are not experiencing the issue? 

 

Although unlikely, does the engine deactivate to two cylinders during idle? Does engaging different engine modes 'E', 'D', or 'S' make any difference?

 

Are VW Golf 1.5 ACT owners reporting similar issues? I could not find anything on a quick google search although I did find a worrying consensus that the 1.5tsi consumption was marginally worse than previously owned 1.4tsi.

 

Nothing mentioned in reviews I have read but then most of those tested were equipped with the DSG.

 

I don't know how you do it but I think a new thread should be set up as a sticky, polling 1.5tsi owners whether they are experiencing the problem. Depending on the results then that provides a service to potential new buyers and puts pressure on Skoda to acknowledge an undesirable characteristic.