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- HDFB110
- Member Since: 22 Nov 2017
- Location: Glos
- Posts: 38
DPF issues -
It seems to me (I'm sure I'll get corrected if wrong!) that most of the oil dilution issues are the result of the DPF getting clogged & not burning off the 'soot' due to the temperature not getting hot enough.
I know this is a basic design issue going back to Land Rover.
Some of the early Disco 5 diesels are getting on a bit now.
There seems to be lots of companies that very quickly start doing 'tuning' upgrades for engine performance & exhaust specialists who do improved exhaust systems.
Does any know if anyone is working on a DPF fix?
You can't just remove it - but surely there are some 'boffins' out there that could come up with a fix to get the temperature up so the DPF works as it should?
OK- yes - doing LR's work for them but there are going to be a lot of D5's over 3 years old soon that need this sort of fix ? -
- HDFB110
- Member Since: 22 Nov 2017
- Location: Glos
- Posts: 38
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Might be answering my own question here !!!!
Just seen that the latest Toyota Land Cruiser (Prado 150) in Australia (all diesel) models has a manual DPF regen switch.
So when you know you are going to do a longer, faster run you flick the switch & do a regen.
Dash apparently will also show when DPF is starting to get blocked - but again you initiate or run the regen.
Leaves the regen decision to the owner/driver.
Almost seems too simple? -
- chicken george
- Member Since: 31 Mar 2018
- Location: N. Yorks
- Posts: 51
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I have a merlo forklift with kubota diesel engine, there is a manual dpf button but you cant just trigger a regen when ever you want,
First it must be 75% full - dash tells you 1/2 and 3/4 levels
engine must be upto running temp
vehicle must be parked, handbrake neutral, hydraulic function turn to off.
Its easier to take to forklift out for a run than do a manual regen, as you have to warm the engine first anyway, but I have used manual on a occasion, mainly when 3/4 light comes on just as you finish use of the machine for the day, shame to let engine cool without completing the needed regen.
oil dilution occurs during active regens not just at the end of failed regens so over use of a manual regen could make things worse.
Chicken George, Land Rover owner for decades , and proud buyer of British products. -
- IndusD4
- Member Since: 28 Jan 2018
- Location: Sydney
- Posts: 698
There was a company here that did what they called a "race pipe". They would remove the DPF filter then put something in so the sensors that remain detect the correct voltage for the car to think it is still there and working properly. But the box that the filter was in was put back in the exhaust so you couldn't tell that it was taken out.
As tinkering with the emissions on your car here is illegal it was called a race pipe as you would only be able to use it when not on the public road, ie a race track or on property.
Ron
2016 D4 TDV6
IIDTool BT -
- IndusD4
- Member Since: 28 Jan 2018
- Location: Sydney
- Posts: 698
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I think it was this mob.
2016 D4 TDV6
IIDTool BT -
- Bogblaster
- Member Since: 12 Dec 2017
- Location: Gloucestershire
- Posts: 32
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Re: DPF issues -
I run a fleet of 15 transits and at about 100k the DPF's start to get blocked as they're full of ash. The DPF's get rid of the carbon by burning it, the outcome of which is ash. The problem with my transits is they are left idling (bloody staff!) and therefore the DPF regen doesn't activate. So they can't reach temperature, then get too full of carbon, the atomiser in the exhaust gets blocked so when it does up to temperature it fails to regen. The bottom line is its £600 in parts and then if we are lucky a forced regen.
The DPF regen on the D5 is similar but different (I have a mate who works at JLR on the fuelling side) It adds extra diesel into the engine when the exhaust is up to temperature and that ignites and burns the carbon, so lots of short journeys where the exhaust doesn't get up to temp leads to blocked DPF's. I once bought a D4 in London and was made to sign a disclaimer that if I blocked it I would be liable for the costs - didn't matter to me as I didn't live there. The oil dilution is a direct relation to this as the car cant tell where it is when it goes into regen, so if you arrive home just as the regen starts the unignited diesel is left in the head and then runs down the bore through the rings and into the oil. I am told that theoretically it will affect every car as it's guaranteed that sometime it will start a regen as the engine is turned off.
HDFB110 wrote:
It seems to me (I'm sure I'll get corrected if wrong!) that most of the oil dilution issues are the result of the DPF getting clogged & not burning off the 'soot' due to the temperature not getting hot enough.
I know this is a basic design issue going back to Land Rover.
Some of the early Disco 5 diesels are getting on a bit now.
There seems to be lots of companies that very quickly start doing 'tuning' upgrades for engine performance & exhaust specialists who do improved exhaust systems.
Does any know if anyone is working on a DPF fix?
You can't just remove it - but surely there are some 'boffins' out there that could come up with a fix to get the temperature up so the DPF works as it should?
OK- yes - doing LR's work for them but there are going to be a lot of D5's over 3 years old soon that need this sort of fix ? -
- harrythespider
- Member Since: 19 Jul 2018
- Location: cumbria
- Posts: 417
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HDFB110..AS I understand it the oil dilution is the result of the regenerations not going full term and needing to be run again and again until a full cycle is achieved. The burning in the DPF is initiated by an increase in exhaust gas temperature which in itself relies on additional fuel being injected into the cylinders,(which causes oil dilution) The process relies on various sensors and software to 'guess' when regen is required.
Apparently the process is hindered by land rovers design of the relevant portion of the exhaust system being overly long on the D5 and consequently over cooling the gases, Simplistically if we knew when regeneration was occurring an additional external (or inside the exhaust system) heat source (induction heater) could ensure adequate temperature was reached and maintained until full regeneration. I suspect it would be possible to use the cars own system to trigger operation of the aforementioned heater but this would require third party software and hardware, which I guess isn't available. -
- Room101
- Member Since: 09 May 2018
- Location: Sacramento
- Posts: 8
Re: DPF issues -
The "pooling" explanation provided above (per Bogblaster) is not correct and implies that a whole load of fuel is left in the cylinders only at the point where an active regeneration is interrupted. This is not so, the problem is caused by active regeneration itself and made worse because of the disproportionate amount of regeneration taking place due to the "architecture & hardware" of the exhaust system. Repeating the erroneous pooling explanation deflects attention away from the real issue and grants JLR a license to keep blaming drivers for using the "wrong driving style", e.g terminating a journey at the wrong time.
The pollution of the oil by fuel has nothing to do with driving style - it is a consequence of the total amount of post injection and exacerbated by the increased probability of an interruption because a) they are more frequent, and b) they have to run for longer than on comparable JLR motor vehicles. I think it is the word "post" that encourages the misunderstanding because it sounds like this is something that happens "after" the regeneration, or after it has been interrupted. In fact the "post" in post injection means after every main diesel injection there is another injection of fuel (not intended to burn in the cylinder) which arrives during each power stroke once the combustion has completed. There are no fewer than 9,000 individual post injections of unburned diesel per minute (150 per second) on the TDV6 when it is turning at 3,000 rpm..
The interruptions serve to increase the overall time that post injection has to operate because an incompleted regeneration usually has to re-start with a cooled engine and exhaust, necessitating an additional 10 minute warm up period using "post injection associated with retarded ignition" (the second type of post injection) in order to get the DPF back up to its regeneration temperature of 1100 F. If the next journey is too short for the regeneration to complete, the dilution will increase further during the warm-up period and the DPF will continue collecting more soot - but little or no regeneration will take place in return. Repeating this cycle a few times will cause the DPF Full warning to appear.
The main dilution process occurs when a tiny proportion of the atomised, post injected fuel is adsorbed into the oil film rather than being ejected through the exhaust port. On each subsequent induction stroke the scraper ring collects a proportion of this concentrated diesel-oil admix and deposits it into the sump. With each stroke the diesel concentration increases by a minute amount as the oil film is progressively washed off and replaced by fuel. Compression rings become less effective and the rate of dilution gradually increases throughout the post injection sequence. This is when metal to metal contact can occur resulting in loss of material from the cylinder walls and piston ring pack. Further damage occurs immediately after the restart because the oil film needs time to re-establish.
When the engine stops rotating before it has had a chance to replenish the oil film, there is little oil seal left to prevent the final injection from running straight into the sump but this is a tiny amount of diesel in comparison to what has been lost already. In a 20 minute regeneration cycle the engine has processed no fewer than 180,000 post injections when rotating at 3,000 rpm: the impact of the final post injections into 2 of the cylinders is negligible by comparison.
This is one of many scientific papers describing the phenomenon.
http://j-mst.org/On_line/admin/files/25-04152_2526-2533_.pdf
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