Diesel - why clouds of black smoke?

WTFH

I notice a few, but very few, and even then it's normally older cars (10+ years old)

I guess one of the issues is people who buy a diesel but never give it a good long drive, so they get DPF problems.

Both cars are currently on Auchan diesel, but if I fill up in the UK it will normally be Tesco or Sainsburys (just depends on where I'm going and where the best value is)

interstellaflyer

andygb wrote: »

Maybe I should have made it clearer - why is our car running so clean?

Your car may do it too, you just might not notice, I think in most cases this happens under certain conditions, I had an Astra Diesel 06 reg, normally it would run clean but under certain conditions you would get a puff of black smoke. I think those cars that smoke all the time do have a problem, however I think most diesels will give the odd puff of black smoke occasionally, under certain conditions.

ilikewatch

I've regularly driven 4 different diesel cars over the last few years:

57 plate 1.7TDAstra (company car) strictly serviced by main dealer according to schedule, only fuelled with Shell standard diesel, started smoking noticeably at 2 years (60K), got a lot worse in the 10K miles before turbo died at 4 years (120K).

60 plate 1.7TDAstra (company car) strictly serviced by main dealer according to schedule, only fuelled with Shell standard diesel, started smoking noticeably at 1 years (40K miles), got a lot worse in the 10,000 miles before turbo died at 2 years (70K).

51 plate 1.9TD Volvo V40 (personal car) never fully serviced after 3 years, oil change every 10-12K, fuelled with supermaket diesel no noticeable smoke when written off in accident at 10 years old with 150K on the clock.

51 plate 1.9TD Volvo S40 (personal car) Main dealer/marque specialist services according to schedule, fuelled with supermaket diesel, no noticeable smoke now at 117K

motorguy

andygb wrote: »

Maybe I should have made it clearer - why is our car running so clean?

Because it is running as it was designed to.

If any car - diesel or otherwise - is belching out black smoke its a sign that something is wrong.

A mate of mine has a 2000 406 2.0HDI with 340,000 miles on it - no black smoke - because its been well maintained.

Ultrasonic

andygb wrote: »

There is nothing like this with ours, and we are both quite spirited with it...

This will help of course, as it will prevent a build-up of soot in the turbo, because you will regularly be spinning the turbo up to decent speeds. Drivers who normally accelerate slowly and potter about all day at very low revs can get a build up of soot, so that on rare occasions when they do have to accelerate a bit harder they can end up with this soot being blown out of the exhaust. This isn't what all black exhaust smoke is, but it's a component.

I'm curiuos how much soot/smoke comes out of the back of my 8 year old 1.9TDi (PD) Octavia, but I never really have anyone I know following me to ask. I certainly can't see smoke in the rear view mirror, even in the dark when headlights tend to make it much more obvious.

mattyprice4004

If the car is modified to have a larger amount of fuel injected, that usually comes with more smoke too.

I have a remap and tuning box fitted to my ZT-T, and it's affectionately known as 'the fog machine' by my friends. Could be a few of the cars you're seeing are modified.

Ultrasonic

mattyprice4004 wrote: »

If the car is modified to have a larger amount of fuel injected, that usually comes with more smoke too.

That's true, I've seen track day videos of a few diesel cars that have been 'tuned', and they often seem to belch out almost comical amounts of smoke!

mattyprice4004

Ultrasonic wrote: »

That's true, I've seen track day videos of a few diesel cars that have been 'tuned', and they often seem to belch out almost comical amounts of smoke!

If I crank everything up, it's very comical indeed... until I have to wash the back of the car.

My friend just bought an i10 - I'm just making up for the carbon he's no longer emitting

GolfBravo

andygb wrote: »

1.9D Octavia, and as I watched the missus leave for work this morning, I realised that there was something missing - clouds of black smoke - even a hint of smoke.

Diesel Particulate Filter.

motorguy

GolfBravo wrote: »

Diesel Particulate Filter.

Unlikely that a 7 year old 1.9TDI has a DPF.

From memory it first went on the 2.0TDI