I was following my car home tonight and it was blowing out more black smoke than I would have thought it should do. It was only when accelerating and briefly as if at the times the car's auto was changing gear. It was recently serviced and MOT'd and there was no issues. It does tend to do short journeys, but about 2 weeks ago did 220 miles twice in three days on the motorway, so it has had a good run.

It is not a DPF version, the tail pipes point down. Is this something I should investigate further?

 

Hi Delta

Have never followed mine to see how much she smokes in normal running but if I floor the accelerator and use kickdown there is always visible smoke from the exhaust that I can see in my mirrors.

 

its quite simple;

if you are using standard diesel fuel, when on high load conditions(like acceleration or steep hills) it has to make some smoke,
tests have shown diesel combustion process, makes PEAK torque occurs at PEAK smoke conditons!

but we cant drive around in those conditions, people would complain,and right fully so.

so fuel mapping is done to reduce smoke and also reduces power.

and so a lot of potential power is left unused for the sake of peace! LOL

plus our newer engines are designed less robust,because we under fuel them.

hope this helps, i do wonder what would happen if we could really raise the mapping in ECU, to find the integrity limits of a 2.7L Jag diesel car.

reasearch costs money, wouldnt be great to have a 4.2L V8 twin turb. engine, with 6spd twin clutch trans

 

Much obliged. It dawned on me that the car would not have gone throught the MOT if something was really a miss.