Motoring myths do they still ring true

[Drago]

Ah, but were your electrons made by recycling dinosaurs or from the wind ?

Wind made electrons smell a bit funny.

 

[Ming the Merciless]

The myth Is people still believe that redex works

Which product as Redex is just the brand?

 

[Drago]

Their lead repladement stuff works.

 

[biggs682]

Which product as Redex is just the brand?

No idea which exact product as all I noticed was the redex branding on the container... You can understand why some people flounce

 

[Gunk]

By what mechanism does Redex clear a DPF?

DPFs block up in two ways:

(1) filling up with soot from the incomplete combustion of fuel. This is what they are designed to trap. Soot is carboniferous and so can be cleared from a DPF through heat - get the DPF hot and it burns away the soot. DPFs can be heated up passively or actively according to how the engine is running. The ECU monitors the pressure drop across the DPF and when needed will trigger an active regen session. Passive regen happens when using the engine hard, increasing exhaust temperatures.

(2) filling up with ash - a residue of the combustion of engine oil. Engine oil contains metallic elements which, when burnt, become metallic oxides (ash). You can’t clear ash by heating the DPF up because ash doesn’t burn. You can only clear it through mechanical or chemical cleaning. The chemicals needed to dissolve the ash are fairly potent and won’t survive coming through the engine combustion process, certainly not at the levels added to a tank of fuel.

Having run modern turbo diesels for many years firstly they’re not really suitable for regular short journeys, however the main issue is that many owners are completely unaware of the passive regen cycle to help the DPF remain unclogged. They just get home and switch the engine off. When I bought our Golf GTD back in 2015 the dealer never told us about the DPF regen, Ì only found about it after reading it on a forum. I made sure whenever possible Ì did the passive regen before turning the engine off. I sold the car a couple of years ago with 140,000 on the clock with no issues.

 

[figbat]

Having run modern turbo diesels for many years firstly they’re not really suitable for regular short journeys, however the main issue is that many owners are completely unaware of the passive regen cycle to help the DPF remain unclogged. They just get home and switch the engine off. When I bought our Golf GTD back in 2015 the dealer never told us about the DPF regen, Ì only found about it after reading it on a forum. I made sure whenever possible Ì did the passive regen before turning the engine off. I sold the car a couple of years ago with 140,000 on the clock with no issues.

Diesels were essentially mid-sold to people for whom they were unsuitable. They were sold on better fuel economy and grunty torque but are not great for short journeys.

People also started panicking when they encountered an active regen, with the car driving a little differently and smelling hot and the fans running on after shut down, because nobody explained them.

Passive regens usually happen naturally with no action needed, but do require certain speed and revs to trigger. Aunt Mable would rarely trigger these regens on the 2 mile round trip to the post office.

And then as the DPF filled up it would trigger more and more active regens which would drive fuel dilution into the oil which wouldn’t evaporate because the engine never got properly warm and so round and round we go in a self-destructive cycle.

When VW got caught with the whole cheat device business I had a Škoda Yeti with an affected engine. They tried to get me to have the official remap update and I refused because I knew it would lead to problems. Sure enough, after updates there were plenty of reports of failed EGR and DPF systems.

 

[Gunk]

I had a Škoda Yeti with an affected engine

Love a Yeti!