Cooling fan running after engine stopped

[SJNoye]

After every drive over 5 minutes, after switching the engine off, the cooling fan kicks in and stays running for approx. 5 minutes. My daily commute to work is 30 mins (20 miles) each way, and when I arrive to work or home and switch the engine off, the cooling fan kicks in. Sometimes after a 10 minute drive, the cooling fan will kick in after shutting the engine off. Some other symptoms I’m experiencing; idle revs are always 950rpm, the start/stop never works, my coolant temperature never exceeds 75 degrees (live data on OBD11). I’m planning to change the thermostat next week as I’m certain the coolant temperature should be up around 90 degrees.
After a long drive, about 40 minutes or so, if I stop the car for 10 minutes, then go to drive again, the idle revs seem to return to 820rpm and the cooling fan doesn’t run after I’ve stopped the car. Any ideas what’s going on please?
My engine is 2.0ltr, CGLC, with automatic gearbox.

 

[jdp1962]

Is the engine diesel?

 

[elan2s]

Yes the CGLC is the 2.0l diesel. Sounds to me like the car is doing a re-gen and has not completed it properly and hence is doing it on nearly every journey

 

[SJNoye]

Yes it’s a 2.0ltr diesel. I haven’t had any warning lights pop up on the dash, and no fault codes in OBD11.

 

[elan2s]

Yes it’s a 2.0ltr diesel. I haven’t had any warning lights pop up on the dash, and no fault codes in OBD11.

With a re-gen you won't get any warning lights or fault codes as it is a normal process for the car. Does OBD-11 allow you to look at the status of the particulate filter. It may be that is very full and hence taking a lot of time to do the regeneration process. A long (1 hour+) motorway drive should go a long way to allowing the regen to complete

 

[NHN]

I'd also consider doing a forced regen diagnostically if it's allowed on that engine, see if that at least helps & drops the soot levels, that would be a good test.

 

[Jon B]

That is deffo regen symptoms.

 

[SJNoye]

So I replaced the thermostat today, and the engine temp came up to 90 degrees after 5-10 mins of driving, as expected, so pleased with that. Absolute nightmare of a job, Audi don’t make things easy?! My concern is that if the engine hasn’t been coming up to proper operating temperature (90 degrees), it hasn’t been doing its DPF re-gen correctly? My symptoms have been going on for about 3 months now, fans running after every drive. I will see if I can see the state of the dpf filter through OBD11. Hopefully now the engine is getting up to temp, and after a good few drives, it may start doing a DPF regen?