Quote:
Originally Posted by 5cilinder
Dude , why to twist every subject into your oilfetish  ?
Dpf's stop indeed ash , but not as an intended cause but as a unwanted consequence.
They are intended to stop (temporarly) soot and to burn it in batches wich leaves tiny unwanted quantities of ash wich will build over time
Point was that bad injectors or to much bhp remaps will create more black smoke but a dpf masks it
(the increased regeneration cycles dont) so know where to look |
I know one end of engine design and related chemistry from another and the DPF designs were a deliberate attempt to do 2 things, firstly make money and secondly to pass the initial emissions tests in the US and Japan WHEN THE DPF IS NEW ONLY!
The car manufacturers refused to use Carbon blocker filters, partly because they are more expensive (Merc and other LeRoy fluid users are far better) AND because they were fully aware that the oil companies would continue using Zinc based additives (If offered some "Financial support"), so they made some big bucks as a result.
Alas for the Carfiosa, an argument with the Far Eastern gangs resulted in "Stop-Start" diesels, which cut the profits a bit.
Zinc ash does not form in a new DPF, BUT as soon as the element is coated in Carbon and warmed up, it sure does. It does a perfect job of making the Carbon deposits more and more difficult to burn out as the unit ages, cos the Zinc compounds formed in the CAT and DPF are reacting with the Carbon clumps, thus acting as a kind of fire retardent!
When some MAFIA elements gave up on the Casino business, they moved into the big fuel and oil game and are still there. They even shut down one small US company that developed an 0w40 full synthetic diesel engine oil that did not use any Zinc or Moly additives, just a German PAO base stock and detergent additives. I don't think you can buy that great oil anymore, as the cars that used it had DPF units that did not collect any Carbon. It was in effect a chemical way of gutting the DPF's and even reduced engine wear as the basic designs failed to Regen and just stayed clean.
I know a lot of Mann diesel and ZF employees and if you ignore their company diesel cars, they all drive classic diesel cars or SUV's THAT DO NOT HAVE A DPF and none of them will admit to using any oil from Castrol or Mobil.
The car manufacturers did cut the max power of some cars sold in the US to make sure they got less DPF failures within the warranty period, as some close tollerance diesels were burning too much oil.
Merc, Porsche and BMW did seem to stay out of the game, apart from the CAFE (Corp Average Fuel Economy) part, but the Chinese, Korean and main US engine manufacturers run the show!
PS: Never trust car or oil company advertising, unless it's from a German company.
Liqui Moly failed to play the Carfiosa game, changed their base stocks for the DPF afflicted and developed Ceratec (Castrol and Mobil marketing must hate the stuff, as it reduces oil consumption and even adds a few MPG for some larger cars), which German car companies love (Along with new contracts for Shell Ultra).
Oddly enough if you want to do an experiment with a blocked DPF or older unit, just drill a hole into the side (Almost right through it), warm up the engine then shut down and then pump dilute Sulphuric acid (Battery top up acid) into the unit until it reaches the fill hole. Leave overnight, then drain (Sorry 2 holes and plug) it.
It will steam a bit (Don't breath it in) for a few minutes, but a few hours on the motorway will then return the DPF to OEM standard, as the Carbon will burn off without a Regen (A Regen early in the clean up run will ruin the result to some extent.