Australasia DFP burn offs

[TheDocAUS]

We need some control or say over DFP burn offs, instead of “helicopter mode” coming on at anytime it decides. I have lost count the number of times burns off decide to start 2 minutes before I get home.

If this occurs in remote Australia in spinifex, the car could be lost by setting fire to the spinifex.

My suggestions:

• When off-road mode is on, no DPF burn offs;
• When the car reaches 85% before a burn off is to start, the driver is notified;
• Any time the car is at 85% or more, the driver can start a burn off, at a time of their choosing;
• if a burn off starts, the driver can stop or delay it.

 

[TheDocAUS]

Has there been an explanation for any of the major Grenadier fires in Oz? (I think there has been three). I’m normally not a conspiracy theorist but they have been very good at keeping the reasons for these fires from reaching social media or this forum, I would have thought at least some info would have come out?

One source was the engine cover in diesel cars melting and catching fire. Hence the recall to replace the engine covers in diesel models with higher rated heat insulation. I do not think the Petrol model has the same problem.

 

[globalgregors]

Can you expand on this for those of us that rarely get to 1,000m mate?

There appears to be some factor associated with altitude that triggers a regen. Air pressure? Oxygenation?
If one is in environments of higher sulfur diesel (eg 15-50ppm) then regen frequency is already increased.

Not necessarily itself a problem however many roads at high altitude also involve severe duty: tight corners, slippery surfaces, steep inclines, mud/snow, perilous drops etc. In these situations the engine bay temperature runs up quickly during a regen and there is no opportunity to push airflow through by speeding up a bit.

Above 4,000m, although the Grenadier performs fine, on a major pass one is usually amongst trucks whose performance is severely compromised at that altitude. Again, it’s just difficult to get the airflow going to mitigate engine bay temperatures. We don’t carry a temp/thermo detector so I can’t be precise, but anecdotally if one opens the hood it’s like a pizza oven in there during a regen.

We have jettisoned our (second!) engine cover, all acoustic pads and installed additional radiant heat shielding.

Other discovery is that the AdBlue system throws a fault at high altitude (>4,500m?), seemingly only if the tank is full.
Fault goes away once one returns to a lower altitude (~3,500m?). Air/Line pressure? Tank expansion?

 

[NQ94]

There appears to be some factor associated with altitude that triggers a regen. Air pressure? Oxygenation?
If one is in environments of higher sulfur diesel (eg 15-50ppm) then regen frequency is already increased.

Not necessarily itself a problem however many roads at high altitude also involve severe duty: tight corners, slippery surfaces, steep inclines, mud/snow, perilous drops etc. In these situations the engine bay temperature runs up quickly during a regen and there is no opportunity to push airflow through by speeding up a bit.

Above 4,000m, although the Grenadier performs fine, on a major pass one is usually amongst trucks whose performance is severely compromised at that altitude. Again, it’s just difficult to get the airflow going to mitigate engine bay temperatures. We don’t carry a temp/thermo detector so I can’t be precise, but anecdotally if one opens the hood it’s like a pizza oven in there during a regen.

We have jettisoned our (second!) engine cover, all acoustic pads and installed additional radiant heat shielding.

Other discovery is that the AdBlue system throws a fault at high altitude (>4,500m?), seemingly only if the tank is full.
Fault goes away once one returns to a lower altitude (~3,500m?). Air/Line pressure? Tank expansion?

Altitude has a large effect on engine performance I would expect the same with the emission systems when the DPF sensors measure pressure to determine soot loading. With construction and industrial engines running permanently above 4500m generally the engines are derated there are different turbos and aftercooler set ups and cooling systems may have capacities increased to cope with the extra heat from combustion, different engine fans and different ambient pressure sensors part numbers as standard types could approach lower operating thresholds. Factory engines are tuned for lower altitudes around sea level to a maximum around 10000ft for some engines, others it's common to be set for considerably less, 3500 to 7000ft depending on the market and application before component changes or a different ECU map is required. Higher altitudes cause higher turbo speeds and over speeding of standard turbos and high combustion temperatures if the fuel isn't dialled back. This was a larger issue on mechanical engines without electronic control.

 

[globalgregors]

Altitude has a large effect on engine performance I would expect the same with the emission systems when the DPF sensors measure pressure to determine soot loading. With construction and industrial engines running permanently above 4500m generally the engines are derated there are different turbos and aftercooler set ups and cooling systems may have capacities increased to cope with the extra heat from combustion, different engine fans and different ambient pressure sensors part numbers as standard types could approach lower operating thresholds. Factory engines are tuned for lower altitudes around sea level to a maximum around 10000ft for some engines, others it's common to be set for considerably less, 3500 to 7000ft depending on the market and application before component changes or a different ECU map is required. Higher altitudes cause higher turbo speeds and over speeding of standard turbos and high combustion temperatures if the fuel isn't dialled back. This was a larger issue on mechanical engines without electronic control.

Oh, that’s very interesting.

In general I’ve found high altitude performance has exceeded my expectations (compared to the baseline of our LR DS). It’s just this one aspect (thermal regulation of the regeneration cycle) that’s an issue.

Low range with access to all gears is just a brilliant combination, I’ve not encountered a situation that the Grenadier wouldn’t just calmly walk through.

The Euro5/Duratorq SD4-equipped LR used to incur oxygen starvation due to the EGR circuit/turbo overrun and power/torque just fell off a cliff up high. Solved by eliminating the EGR.

 

[Shopkeep]

There appears to be some factor associated with altitude that triggers a regen. Air pressure? Oxygenation?
If one is in environments of higher sulfur diesel (eg 15-50ppm) then regen frequency is already increased.

Not necessarily itself a problem however many roads at high altitude also involve severe duty: tight corners, slippery surfaces, steep inclines, mud/snow, perilous drops etc. In these situations the engine bay temperature runs up quickly during a regen and there is no opportunity to push airflow through by speeding up a bit.

Above 4,000m, although the Grenadier performs fine, on a major pass one is usually amongst trucks whose performance is severely compromised at that altitude. Again, it’s just difficult to get the airflow going to mitigate engine bay temperatures. We don’t carry a temp/thermo detector so I can’t be precise, but anecdotally if one opens the hood it’s like a pizza oven in there during a regen.

We have jettisoned our (second!) engine cover, all acoustic pads and installed additional radiant heat shielding.

Other discovery is that the AdBlue system throws a fault at high altitude (>4,500m?), seemingly only if the tank is full.
Fault goes away once one returns to a lower altitude (~3,500m?). Air/Line pressure? Tank expansion?

Sounds like you need some old fashioned bennet louvres. There are the cosmetic plastic blanks at the back of the Grenadier bonnet, I wonder if the aftermarket could find a way to replace these with functional vents (the double wall structure underneath would make it hard but there may be a way).