High RPM on startup

[aliveandflipping89]

Hi all I recently purchased a 2020 octavia 3 1.0 tsi on and I am loving it so far BUT I’ve noticed when the engine is cold in the morning it seems to run at about 1500rpm for a little while and then settles back down to about 1000rpm? Is this normal? I’ve have heard on some cars that the wastegate fully opens to get the cat warm quickly? Is that what is happening here? Any help or input would be greatly welcomed. 

[Ootohere]

Welcome.

That is what can happen, there is a Catalytic Converter but also a Gasoline Particulate Filter. 

 

http://briskoda.net/forums/topic/508507-car-accelerates-quickly-when-cold-and-has-high-idle-if-you-switch-off-when-cold-and-restart

 

Edited 22 February, 2023 by toot

[aliveandflipping89]

Just now, toot said:

Welcome.

That is what can happen, there is a Catalytic Converter but also a Gasoline Particulate Filter. 

Thanks for reply I also forgot to add it seems to happen when engine is stone cold. 

[nickytheshaft]

this is normal, the ecu will raise the rpm on cold start as you would have done with a chock on a carburator car. 

When the engin reaches working temperature the rpm will drop.

[Ootohere]

What is normal is that it is 1,500 rpm because and it is 3 cylinder 1.0 TSI,s with a GPF.     Other 4 cylinder TSI engines 1.2, 1.4, 1.5, 1.8, 2.0 with or without a GPF might go to 1,100 rpm for 40 seconds then drop to 850 or 800 rpm.  

[Vahids]

Not directly similar to this issue, mine (1.4TSI 2013 67K) has a different (strange) start RPM behaviour. Starting from semi-warm engine (after an hour or two hours of using the car) randomly, RPM goes to 1200-1300 at start and then drops to 600 within 30 seconds. But, it never goes that high when start from stone-cold. Not sure what the reason could be. 

[varooom]

4 minutes ago, Vahids said:

Not directly similar to this issue, mine (1.4TSI 2013 67K) has a different (strange) start RPM behaviour. Starting from semi-warm engine (after an hour or two hours of using the car) randomly, RPM goes to 1200-1300 at start and then drops to 600 within 30 seconds. But, it never goes that high when start from stone-cold. Not sure what the reason could be. 

Probably related to the battery, as the J519 controller can override the revs to recover power (though that figure seems high) and too short to be a GPF regen cycle I would say.

Maybe some more answers will come from other members soon.

[Ootohere]

No GPF on a 2013 1.4 TSI anyway so not related. 

As to the RPM. look closer, is it really as low as 600 rpm?

 

Is it a DSG or Manual.  In it in N at 600 rpm in Manual or even a DSG? 

 

  If a DSG in P or N at 600 rpm, surely not in D with foot on brake pedal and certainly not in S. 

 

..........................

With 1.2 TSI's Skoda want employees to get customers to be persuaded that rough runners are 'they all do that's'.

http://briskoda.net/forums/topic/504258-a-tsb-from-skoda-on-cold-start-behaviour-with-12-tsis-something-that-dealership-employees-should-be-able-to-explain-to-customers

 

Edited 24 February, 2023 by toot

[Vahids]

24 minutes ago, varooom said:

Probably related to the battery, as the J519 controller can override the revs to recover power (though that figure seems high) and too short to be a GPF regen cycle I would say.

Maybe some more answers will come from other members soon.

Thanks for your reply @varooom, I also thought it could be related to the battery before I change the battery to a new (AGM) battery a month ago. With the new batter everything works as expected (like start-stop etc). But, I still randomly experience the high rev issue. I coded the battery properly. 

[Vahids]

20 minutes ago, toot said:

No GPF on a 2013 1.4 TSI anyway so not related. 

As to the RPM. look closer, is it really as low as 600 rpm?

 

Is it a DSG or Manual.  In it in N at 600 rpm in Manual or even a DSG? 

 

  If a DSG in P or N at 600 rpm, surely not in D with foot on brake pedal and certainly not in S. 

 

..........................

With 1.2 TSI's Skoda want employees to get customers to be persuaded that rough runners are 'they all do that's'.

http://briskoda.net/forums/topic/504258-a-tsb-from-skoda-on-cold-start-behaviour-with-12-tsis-something-that-dealership-employees-should-be-able-to-explain-to-customers

 

Thanks for your reply @toot, it is a manual. What I really meant from 600 was the minimum it can go down, maybe it is 750 rpm.

[Ootohere]

That about where it should be 750-800 rpm.

1.4 TSI Twinchargers were up to 1,100 rpm and by 45 seconds to 800 rpm.

When someone asked me to check out a car for them that was the first thing i checked they were doing before looking at the air filter to see the state of that.

Then it was the spark plugs having plugged in and checked if any fault codes. misfires in a cycle etc.

Simple stuff first. 

http://briskoda.net/forums/topic/510569-how-do-i-increase-the-dle-speed-on-a-2014-14-vrs

 

Edited 24 February, 2023 by toot

[Vahids]

21 minutes ago, toot said:

That about where it should be 750-800 rpm.

1.4 TSI Twinchargers were up to 1,100 rpm and by 45 seconds to 800 rpm.

When someone asked me to check out a car for them that was the first thing i checked they were doing before looking at the air filter to see the state of that.

Then it was the spark plugs having plugged in and checked if any fault codes. misfires in a cycle etc.

Simple stuff first. 

http://briskoda.net/forums/topic/510569-how-do-i-increase-the-dle-speed-on-a-2014-14-vrs

Just to be clear, I don't complain about the low RPM, just wondering what could be the reason for random  1200-1300 RPM with semi-warm engine. I have scanned the car with VCDS, there is no error.

[varooom]

6 minutes ago, Vahids said:

Just to be clear, I don't complain about the low RPM, just wondering what could be the reason for random  1200-1300 RPM with semi-warm engine. I have scanned the car with VCDS, there is no error.

It might be an idea to log the Alternator output to see if it's replenishing the power rapidly, that would maybe explain the increased RPM on startup

 

Here you can see the Alternator stepping down output over time, so perhaps worth looking at your values