Hi folks. Hope you can point me in the direction of possible causes of my engine doing strange things.

At the moment at cold start-up (ambient temperature is -2 to +7 oC) the car (diesel scout) reving at 1000rpm. If I turn it off it'll run at 750rpm again but slowly creep back up to 1000rpm over the next minute.

 

The other day at -2 and a cold start the fan came on after a 2 mile journey and stayed on for 5 minutes after the engine was turned off.

 

I've replaced the thermostat (what a sod of a job) so it's not that (confirmed by garage.

 

Anyone got any thoughts as to what it might be? I'm thinking that a sensor is faulty, but which one??

 

Thanks

Given it's a diesel, that sounds like it's trying to perform a DPF regeneration.

 

 

What sort of usage does the car normally get? If it's shorter journeys it might be struggling to perform a full regen given the ambient temperatures.

 

I drive from Cheshire to Gloucestershire every couple of weeks, so that's 2.5 hours of motorway cruising each way. Add in weekly trips to Birmingham and it kind of rules that one out sadly.

8 minutes ago, BushcraftChris said:

I drive from Cheshire to Gloucestershire every couple of weeks, so that's 2.5 hours of motorway cruising each way. Add in weekly trips to Birmingham and it kind of rules that one out sadly. 

 

It doesn't unfortunately.

 

The last trip I did back from London,up the M1/ M6, cruise set at 70 apart from the 50 roadworks, non-stop.

 

The very next day on a local trip the car did a regen.

 

It does it when the ECU decides it is due.

Last week in a 2.0TDI SCR DSG i drove about for a few days in around freezing conditions with the longest runs being 3 miles, 

and after 4 days the DPF light came on and i took it for a 6 mile jaunt and the light was out.

 

This weekend i did over 500 miles, but by Thursday this week with the temp around freezing i expect the same will happen again after maybe 15-20 miles of just using the car a few miles from each cold start.