DPF and white smoke

[nudgebar]

If a new DPF only cost a couple of hundred ( and i suspect thats all it worth to produce ) then replacing it every 100,000klm or whatever would not be an issue. but since Toyota are charging $3000+ for a new DPF then it does become a ripoff.

its like that with all parts - the production cost is tiny compared to what parts outlets charge , hence the problem.

[JohnLynn]

Yes it does look like injecting diesel into a hot enough exhaust produces white smoke. This is a quote from the Red Arrows display team website about how they generate different coloured smoke:
"The basic vapour colour is white, produced by injecting diesel into the hot exhaust from the jet engine. This reaches temperatures of over 400 degrees centigrade and vaporises immediately. The blue and red colours are made by mixing dye with the diesel. The dye and diesel is stored in a specially-modified pod fitted to each of the aircraft."
So perhaps we could modify our Prados with some dye and make a display worth watching?
@CamJam was your invoice split to show the different costs of parts and labour? I am interested in how much a DPF unit would cost.

[rpn]

There is no way that the amount of smoke coming from these is "normal". That just sounds like an easy-out for Toyota, because i think they are going to be flooded with 2.8's suffering this problem. The Hilux i saw was literally leaving a white smokescreen behind him. Sure, it may not be damaging the engine itself, but it has to be embarrassing for the driver and surely not healthy for anyone following closely behind. I'd be driving straight to the dealer and demanding a loaner while they fix/replace the POS DPF.

Many years ago I was at an event where a Austin Champ 4WD had a washer bottle rigged up to squirt diesel into the exhaust manifold of the petrol engine (just for giggles). It produced huge clouds of white smoke, so it sounds like the smoke from the DPF is some sort of fault where too much diesel is used for the burn and maybe doesn't affect the engine at all.

[prodoco]

Update 2

DPF replaced on Monday this week (30/10/2017), it took approximately 4 hours to finish the replacement job. The new DPF makes the car breathe/fart easier and exhibits better throttle response.

[CamJam]

..

[CamJam]

Update

So I had the DPF replaced yesterday, and have since done 520km's. So yes, it's early days... but

When I first got the Prado I was getting mid-9's for fuel consumption. Then the white smoke started to occur and it crept into the mid-10's. But I thought it was due to the Bull Bar, Recovery points, Pioneer Backbone rack, UHF aerial and a few other things that would have ruined any aerodynamics it had, and added weight.

However, towards the 30,000km mark the fuel usage (and white smoke) really started to go up - to an average of around 11.8/100km.

At around 20,000km I also started to have a really annoying squeal (almost like brake pads wearing) under load. My air con went on/ off, I floored it, I put it in neutral - nothing was really changing this squeal - it ended up just getting worse, and was almost without fail coming on at the same point on my drive home every day (coasting in an 80km zone). The best description for the sound came from a mate - he thought it was those really really loud cicada's that you sometimes hear camping that constantly chirp.

So the DPF got replaced. My fuel economy is back in the mid-9's. There is no squealing.

I'm not saying the DPF caused the squealing (but I suspect it now) but if anyones got that squeal (there's a seperate thread for it) - then something around the DPF - if not the DPF itself - is causing it. THat's where I'd be looking.

I note on the invoice (free for me, but $1445 was on it) that there was a 'Gasket Turbine' replaced (as well as a Gasket exhaust pipe, DPF and Converter sub-assembly) - perhaps that was it? It'd explain that, if it were the Regen causing the squeal then why my attempts to stop it didn't work. It'd also explain why it came on at the same point on my drive home - it'd always probably be up to temperature by then (it's about 25km into it).

So - with fingers on a lot of wood - I think a new DPF has solved thee problems. White Smoke, fuel economy and the squealing. I'll let you know if any of it comes back.

[CamJam]

I thought the diesel we use in Australia is low sulfur?

In theory we do. And while I am getting a DPF replacement tomorrow, I thought over the past 5000km's I'd take it to another service station for fuel, which has led to NO white smoke whatsoever. The two I used to go to are both reputable (Caltex Vortex and BP Ultimate), however they were a little dingy and didn't quite look as new or up-spec as some.

I'll continue to go to this new servo (another Caltex, but sadly no rewards points) when I get the new DPF - just in case this 2.8L is really sensitive to the fuel/ sulphur. I know they should all come from the same truck, but hey - it's worked so far in that I haven't seen any white smoke over a period that I would usually have seen three or so decent blows of it...

To anyone else who's got the white smoke - could I suggest another servo (and stick with it for three tanks at least)? It was an idea originally thrown at me by the Toyota mechanic...

[CamJam]

Double-Post removed

[CamJam]

Trueblue - there's a reason why my car is in tomorrow having it's DPF replaced after the white smoke... I'm putting it out there that it's not simply to appease a customer... that's not really the Toyota way is it? Can't wait to drive with the new one installed and see how they go.

One odd thing - I used to always get 10.5L/100km, then post the recall this jumped to around 11.5L/100. After they thoroughly checked the car out, they decided that the DPF was cactus. But whatever they did for those many hours they were working on it (I waited), certainly did something - my fuel usage over the past month or so has gone back to 10.7L/100km. So after the replacement tomorrow, then I will certainly keep an eye on the consumption - these faulty white-smoke DPFs might be costing us more than embarrassment and time at the dealership...

[LeadWings]

Analysis of Sulfur-Related White Smoke Emissions from DPF System

• 2015-01-2023

Abstract:

In a Diesel engine with a Diesel particulate filter (DPF) system, high-sulfur fuel ........

I thought the diesel we use in Australia is low sulfur?

[JohnLynn]

On a lighter note, since I have only just noticed this issue with the DPF I have been trying to read up all I can about it. There are several videos on youtube including some quite long lectures into the subject. The videos discuss the pros like less pollution and the many cons.
Some people choose to "delete" there is a two part video a company has made which involves taking everything off a truck with a six litre Cummins diesel.
They remove the EGR valve complete with it's cooler the DPF and also the catalyst for adblue and associated tanks. The complete exhaust system is replaced with 5 inch diameter pipe and presumably the ECU is reprogrammed to not notice all this stuff has disappeared.
Apparently this makes the engine run much more smoothly, becomes much more economic and unleashes a vast increase in power.
To prove how good it is they accelerate the truck up the street in record time but film from the rear and as the boot is put down the truck belches black smoke as it roars up the road. I thought that this was the point of all the stuff they had just removed.

[brogers]

Analysis of Sulfur-Related White Smoke Emissions from DPF System

• 2015-01-2023

Published:

• 2015-09-01

DOI:

• https://doi.org/10.4271/2015-01-2023

Citation:
Hirano, T., Goto, I., Kitano, K., Kojima, T. et al., "Analysis of Sulfur-Related White Smoke Emissions from DPF System," SAE Technical Paper 2015-01-2023, 2015, https://doi.org/10.4271/2015-01-2023.

• Download Citation

Author(s):

• Takahiro Hirano
• Isamu Goto
• Koji Kitano
• Takayoshi Kojima
• Masatoshi Ikeda

Affiliated:

• Toyota Motor Corporation
• Nippon Soken, Inc.

Abstract:

In a Diesel engine with a Diesel particulate filter (DPF) system, high-sulfur fuel causes white smoke containing odorous and harmful pollutants during DPF regeneration. This study investigates the conditions and mechanisms of sulfur-related white smoke generation.Engine and vehicle tests found that sulfur compounds emitted from the engine accumulated on the catalysts in the DPF system and were emitted as white smoke during DPF regeneration. The white smoke was observed when the catalyst temperature was more than 450°C, under conditions such as the early stage of DPF regeneration.Model gas tests were conducted to clarify the mechanism of the white smoke. It was found that SO2 emitted from the engine was oxidized to SO3 on the catalyst, which was then mainly absorbed on the oxidation catalyst support (Al2O3). Then, the absorbed SO3 was desorbed and converted into white smoke. The intensity of the white smoke depended on the amount of desorbed SO3 and the rate of temperature increase of the catalyst.

[diesel69]

Unburnt diesel....

If only it were that simple.... unfortunately the information I have been given by a diesel mechanic in the trucking industry is that the chemicals produced by a DPF burn off (even when not functioning correctly) are extremely harmful and should not be inhaled as they are possibly carcinogenic

[cuda]

while on the subject , i wonder what the chemicals in that smoke are ??

Unburnt diesel....

[cuda]

while on the subject , i wonder what the chemicals in that smoke are ??

Unburnt diesel....