I have a 2014 Skoda Superb (2.0 Diesel) and I am not sure if my car has an underlying issue when the weather goes cold. During the cold weather the tickover revs on the car go upto around 1000rpm and sometimes the radiator fan is running even though the engine temperature is not high. Does anyone know what could be causing this ? Thks

DPF regeneration.

Both of my mk2 superbs (2013 elegance 20.tdi 140 & 2015 L&K 2.0tdi 170) have done this when it’s cold & you have a lot of comfort functions on like heater, ac, heated rear screen, heated seats etc. It’s nothing to do with the DPF regenerating although that also causes the ideal to raise to about 1000rpm. The idle settles down back to normal a while after the engine gets up to temp. It’s perfectly normal. 

Most likely the regen.

As to the cold start and higher RPM and load on the battery and alternator putting charge into the battery. = the rise to about 1,000 rpm.

12 hours ago, FootOut said:

Both of my mk2 superbs (2013 elegance 20.tdi 140 & 2015 L&K 2.0tdi 170) have done this when it’s cold & you have a lot of comfort functions on like heater, ac, heated rear screen, heated seats etc. It’s nothing to do with the DPF regenerating although that also causes the ideal to raise to about 1000rpm. The idle settles down back to normal a while after the engine gets up to temp. It’s perfectly normal. 

The idle does not go back to normal when cold and also my air con does not work also during normal weather it does seem to do a regen quite regularly probably every couple of weeks with me driving a minimum of 60miles a day 5 times a week, if driving around town the higher idle is happening until I get on to the motorway.

 

How often should a regen occur and how long does it normally last?

 

Thanks

Ah right. That’s not normal then. My idle drops back to normal a few miles after the coolant reaches 90°. The regen frequency depends a lot on whether the car has had the dieselgate emission ‘fix’. People that followed the recall and had the update have much more frequent regens and a lot had EGR & DPF issues. My 2015 2.0 170 had the ‘fix’ before I bought it. It was regenerating every 100-120 miles. I had it rolled back to the ecu software file I left the factory with and it’s now every 270-300 miles with my regular 30 mile a day rush hour commute with lots of stopping and starting. If I’m doing motorway runs it goes much further between them. A regen usually takes around 15-20 mins. Car is way nicer to drive too, smoother and more torque. 
 

do you have one of the DPF monitor apps to check it’s actually regenerating? They’re really useful. They tell you the ECU software version too so you can tell if it’s had the dieselgate update or not. 

Edited 30 December, 20232 yr by FootOut

19 hours ago, FootOut said:

It’s nothing to do with the DPF regenerating although that also causes the ideal to raise to about 1000rpm.

 

Combined with the following it definitely is:

 

On 28/12/2023 at 17:25, JAK68 said:

sometimes the radiator fan is running even though the engine temperature is not high

 

But the fan could be the aircon, I am rarely aware of the AC fan running but usually aware of the high speed fan running during a regen, the giveaway of course is the fan running after engine shut down.

 

I do agree with the high idle after a cold start with heavy electrical load.

 

And just to confuse things all the more:

 

7 hours ago, JAK68 said:

The idle does not go back to normal when cold and also my air con does not work

 

The AC will not work below a certain temperature, 3 or 4° C I seem to recall.

14 hours ago, FootOut said:

Ah right. That’s not normal then. My idle drops back to normal a few miles after the coolant reaches 90°. The regen frequency depends a lot on whether the car has had the dieselgate emission ‘fix’. People that followed the recall and had the update have much more frequent regens and a lot had EGR & DPF issues. My 2015 2.0 170 had the ‘fix’ before I bought it. It was regenerating every 100-120 miles. I had it rolled back to the ecu software file I left the factory with and it’s now every 270-300 miles with my regular 30 mile a day rush hour commute with lots of stopping and starting. If I’m doing motorway runs it goes much further between them. A regen usually takes around 15-20 mins. Car is way nicer to drive too, smoother and more torque. 
 

do you have one of the DPF monitor apps to check it’s actually regenerating? They’re really useful. They tell you the ECU software version too so you can tell if it’s had the dieselgate update or not. 

Thanks for the info 👍

 

I have actually just recently downloaded this app on my phone https://play.google.com/store/apps/details?id=com.ovz.carscanner but unsure if it will show the regen, are you able to recommend any DPF monitoring apps?

 

Thks again

On 31/12/2023 at 07:11, JAK68 said:

Thanks for the info 👍

 

I have actually just recently downloaded this app on my phone https://play.google.com/store/apps/details?id=com.ovz.carscanner but unsure if it will show the regen, are you able to recommend any DPF monitoring apps?

 

Thks again

If you buy OBD Eleven, you can check last time regen was done. Also during driving regen can be detected if temp sensors 1, 3 and 4 goes up to 550+ celcius temp during driving under normal throttle load.

OBD Eleven Pro is the scanner I would recommend or even better; the VCDS Unlimited. I have both and use them every other time, depending what I need to have coded og monitored.