Hello! I just started my journey with superb.

 

It has 2.0litee CBBB engine. Sometimes at idle it rises idle about 1000rpm. Coolant fan runs sometime at low speed (there is -10 outside and engine is not for sure hot).

 

What causes it?

 

If i wanna install auxilary heater, is there somewhere fuel supply? 

Most likely you are not letting it complete a DPF regen or taking it on a long run. 

2 minutes ago, gav_is_con said:

Most likely you are not letting it complete a DPF regen or taking it on a long run. 

How often it will regen DPF? And how long run it takes to regen?

6 minutes ago, Karpov said:

How often it will regen DPF? And how long run it takes to regen?

https://www.rac.co.uk/drive/advice/emissions/diesel-particulate-filters/

On 14/12/2024 at 00:38, Karpov said:

How often it will regen DPF? And how long run it takes to regen?

Depends on driving conditions. Lots of small town driving will enforce more regens. Lots of long distance driving, not so much. But do tale it serious because if ignored, the dpf will eventually be to clogged and even service regen or forced regen wont help. Then it is replacement of mechanical cleaning. 

Today -25 and i started car. After 30s idling again fan on. Ive been driving long trips so could it be dpf? And will car start even dpf regen with cold engine?

 

 

Edited 17 December, 20241 yr by Karpov

3 minutes ago, Karpov said:

Today -25 and i started car. After 30s idling again fan on. Ive been driving long trips so could it be dpf? And will car start even dpf regen with cold engine?

 

 

Yes, car will start even if a regen was interrupted last shut down. it will continue next start until finished. But if you keep interrupting, well, then it will get clogged in the end.

If you have access to vcds, it might be smart to do a forced regen while driving. it takes about 30min and you have to drive at good speed, I would say above 80 and preferable with engine load. So find yourself a route with relative flat driving conditions or a 20-30min slope where you are able to keep the pedal more on the plus side than on the idle side 🙂 

As I could remember from my several trips along E8 in northern part of Finland, there should be plenty of space to really get the engine running in maybe not so legal speeds all the time....;-)

 

Okay thanks. Nothing else that regen wont kick fan on at cold engine idling?

When a forced regen is taking place, you can monitor the engine temp exhaust gas temp nr 1, 3 and 4. And there you wil se that they will likely be constant above 550 degrees and sometimes up to 750 degrees when driving your normal long trip route in 80-90km/h. When forced regen is finished, the temps normalizes again and you will seldom see temps above 400 degrees when doing the same route in the same distance doing 80-90km/h.

1 minute ago, Karpov said:

Okay thanks. Nothing else that regen wont kick fan on at cold engine idling?

Not that I am aware of. If, you by any chance have the fans go all wild every trip and for a prolonged time after shutting down the car, I would actually get it checked since regen doesnt/shouldnt happen that often. maybe a relay or some electric connection is bad. 

Oh, yes, and regen will not start before coolant temp is above 70 degrees. So If fans start wild chase 30sec after start up with cold car in -25 degrees, that is a bit odd. Don't think that is because of regen, but I am not an expert, just writing what I have been told by mechanics and other more dpf competent people...

 

My car also rise the engine speed from 750-800 rpm at cold start up to 1000-1050 rpm after just a couple of minutes. it could be the engine speed rising due to alternator charging battery. I think that is the case, since i scan my car with vcds and regularly do a forced regen. i know that my cars dpf is way inside specs when it comes to soot levels. So, have noticed the increase in engine rpms myself. I think it is normal. Been like that for 2 years.

Edited 17 December, 20241 yr by rbhelle

And when fan turns on, its not full power. You hear it but its not like summertime hot. Or is superb fan allways quiet?

 

Ive seeking for vagcom so i can see data (only have old blue cable). Basic elm bt obd said no fault codes.

 

 

Btw is there coolant temp limitations for heater ptc? Today was pretty warm inside cabin even outside was cold. Coolant temp reached only 65c but thermostat is known to be bad.

 

I got new one but changing it seems need some disassembly

I keep an eye on regens using the VAG DPF app and Carista OBD2 bluetooth scanner.  Always try and allow a regen to complete before parking up or stopping the engine, even if I have to drive a mile or two longer to allow it to complete.

 

Thats a preventive habit Tasman. Not always wifey is agreed in this household 😀

Thats a preventive habit Tasman. Not always wifey is agreed in this household 😀

Edited 18 December, 20241 yr by rbhelle

17 hours ago, rbhelle said:

regen will not start before coolant temp is above 70 degrees. So If fans start wild chase 30sec after start up with cold car in -25 degrees, that is a bit odd. Don't think that is because of regen, but I am not an expert,

 

Agreed that it makes no sense but mine did that after a couple of interrupted regens, it could not possibly have been regenerating from a cold start but I took it as a reminder to do a longer journey, I had done a 1000km autoroute journey and could see from VCDS that it had regenned 3 times during the journey despite practically zero soot building up, when it tried to do so every time I drove the next week (my journeys were around 10km) including from cold starts I decided enough was enough, I paid to have the emissions fix rolled back and have heard the fans running after shut down maybe twice since then, not for over a year now.

 

I can see from VCDS that its doing an active regen every 1000kms.

Okay i had to check vcds.

 

How about is there been faults at burned light monitoring? Check rear right reverse light keeps on appearing and burned bulb symbol. Lights are working and ive been replaced bulb also.