Ad blue usage

[Frankzy]

Tier 4f sisu 4.9l have a DOC that can be cleaned with a regen apparently

Huh, the more you know..

Does the Deere not have dpf aswell tho?

And EGR.

 

[Timbo]

You're surely talking about the DPF needing to regen, I've never heard of the DOC being regenerated.

DPF's require regenerate when they are upto to a certain soot loading (80% ish, depending, as measured by two pressure sensors) by either an extra diesel injector in the exhaust that sprays in fuel, or by having the main injectors do a very late (retarded) squirt that lights up in the exhaust manifold . Note that over a period of time the soot leaves ash residue behind that is stuck inside the DPF and will at some point require replacement, or washing / cleaning out of that ash.

DOC / Oxydation cats just require a certain amount of temp to work. End of. They go someway to using spare oxygen in the exhaust to burn up (some) soot particles.

NOx traps require ad blue or DEF to reduce the NOx's to nitrogen and water. The more NOx the more ad blue needed as measured by two if not three . High NOx levels are a result of HOT and GOOD combustion - therefore the less "tune" an engine has and the more EGR it runs, the less NOx it will produce. The NOx in the exhaust and after the trap is measured by two if not three sensors. One is often a wide band oxygen sensor that feeds back to the ECU to make sure the engine always runs suitably lean to help the DOC work most effectively.

 

[Pheasant Surprise]

As above a DPF is a “closed” honeycomb of ceramic that traps the soot. It’s a fancy sock. It will eventually fill up with enough soot that it needs to burn this off, aka “a regeneration”. Even so after x regenerations they eventually bung up with the resulting ash from burning the soot, and you need to replace them altogether (or get the 16 mil long masonry bit out ).

A DPF engined tractor must be run with a low SAPS oil, otherwise using a non-SAPS oil, the oil that doesn’t get scraped by the oil control ring etc gets burnt, but importantly it forms ash when it burns and this prematurely fills up the DPF.

A DOC is constructed much like a catalytic converter on a petrol car, it is “open” and can’t block up as such, but it’s still possible to poison the catalysts using older “high” (non 10ppm) sulphur diesel

 

[Zebbedee]

Should use between 7 and 11 percent as a rough guide remove adblue injector and make sure hole not blocked also correct engine oil

That’s what I’m told as well by manufacturer but it’s a hell of a lot and an ibc don’t last long