OT - Dieselgate again

Didn't it work out the car was on a rolling road by the lack of steering moment? Or one pair of wheels not turning?

[...]

No idea; VOSA used to do them, and they were more comprehensive than just a smoke test. They withdrew, and handed responsibility to local councils, who don't have the funding to carry them out.

I'm not sure you would need to carry out a test 'under load' where the vehicle being tested could be emitting 20 times the permitted level of NOx however.

Chris

Probably both those things and more; full details are yet to emerge from what I can see.

Chris

But the whole point is they didn't, at all times.

It's on Wikipedia:

Basically, a 'green' non-profit was doing a fairly random sample, and found the discrepancy. IIRC, VW fronted it out when first approached and denied wrongdoing.

Several thousand people will die early as a direct result:

The 2011 Skoda 1.6 diesel (not yet modded by Skoda) I had seemed to have a flat-spot at 1500 rpm (30 mph and 50 mph) where the engine seemed a bit "wobbly" under light load. That may be an emissions testing "flat spot".

If they reduced air flow at the testing points to lower emissions they would have had to alter the fuel flow as well to keep air \ fuel ratios within acceptable limits to keep combustion going. Smart though they might be, you can't beat combustion chemistry.

I was told by Skoda there would be a software update and a mod in the airbox put something to affect air flow. I suspect the mods will only affect the air \ fuel at certain points (i.e. the mandatory testing points specified by the various vehicle approval and testing bodies).

In the case of the Skoda, I'd guess you will get it to 2000 rpm when the turbo starts to work and it will still feel the same as before.

However, I've voted out and sold it, not waiting to find out.

I often notice diesel cars bellowing out puffs of black smoke, even modern mercs and the rest. I know that they nominally have filters and urea from the factory, seems that these are removed? Following behind a diesel car might damage the headlamp reflectors over time.

[...]

Assuming it's not an old heap, the smoke you see is the DPF regenerating. Only early versions use an additive; anything vaguely recent uses extra fuel to burn the deposits off the filter. The smoke is harmless.

I'm not sure that would be an issue.

Chris

You see diesel dust on houses near major roads. It is not an immediate effect, but it shows up over time. Extended time (over years) does strange things which you don't notice at first. The concentration of diesel smoke behind a diesel car is quite obvious, and I'm sure that this caused my headlamp reflector to fail at the last MOT.

the plastic lens is just about feasible, but not the relector. You could also try leaving a larger braking distance.

[...]

:-)

Chris

The lens is glass, but diesel gets in through the surrounds or at the back. Extended time (years) is the factor. I'm certainly not a tailgaiter, quite the opposite. Most cars on motorways these days are diesels, obviously business cars to a large extent. Some executive cars you can now only only get in UK as diesels. I've seen black smoke from modern mercedes. There is a constant blanket of diesel hanging over the motorways. Have you tried standing in the hard shoulder?

[...]

Did you read my post explaining why?

Chris

Quite infeasible. Have you ever changed a headlamp bulb?

The lens is sealed to the reflector. If this seal fails or you get a stone chip your lamp will have condensation in it.

The bulb is a close fit the hole it seats in.

All cars made in the last 35 years have rubber seals over the bulb holder connector to the rear of the lens or the whole assembly. This will have a small right angle vent tube about 10sq mm pointing downwards. This allows expanding air warmed by the bulb when it is on to vent and fresh air to be drawn in when it is switched off and cools. The only time it draws air in will be while you are parked somewhere unless you are prone to driving though the dawn.

I doubt this. Doesn't regeneration take about 20 minutes? I've never followed a diesel spewing smoke for that long.

You'll be calling I unburnt fuel a tonic next. ;-) Seriously, it may be less harmful due to particulate size (maybe) but harmless? I think not.

Plenty of modern diesels still spew the black stuff when booted hard. It may be a fault, but it's still pretty common.

Tim

More like 10 minutes. The smoke will be most noticeable only for the first period of post-combustion injection.

Harmless in terms of particulate pollution, which is the big problem with diesels now.

It's not something I've noticed. The occasional puff when booted following a long period of slow speed, but I haven't noticed it other than that.

Chris

Big difference between a steady burn and "bellowing out puffs of black smoke". That really doesn't sound like regeneration.

Just recent followed two different 3L BMWs, both chucking out the black stuff under heavy acceleration. See plenty of Mondeos doing it too (although less frequently).

Tim

So the haedlamp is not hermetically sealed, air can equialise with the surrounding area. After a couple of hours on a saturated motoway, the air inside the lamp will be motorway-air. You won't see the immediate effect of the diesel deposits, but long term perhaps 10 more years. Time does strange things. Houses near major roads you can see diesel deposits, even on inside walls; try putting a wet cloth to the wall. Again, the air equalise with the outside over time.