Keep glowplugs on for longer?

[michaelovitch]

I suggest you to heat up your biodiesel if you run 100 % of it.
it will allow you to be near the viscosity of the diesel fuel even in winter with a "standard" tune (0.95 or more for sure) for your injection pump.


the injectors must open at bigger pressure too if you run biodiesel it's 155 bars stock and i would say at least 10 more bars for biodiesel.


If you want to start with pure biodiesel you should install a heater in the intake line of the pump or reduce the percentage of biodiesel (so to make a mix with fuel) to reduce the viscosity.


the viscosity is very important !

the VE pumps are very strong but are designed to run with diesel fuel not vegetable oil
they can break quite easily in winter.


viscosity create more stress on the moving parts and crappy atomization in the pre chambers and glowplugs break because of the localized stress during the bad combustion (don't forget the combustion starts in the prechamber where the glowplug is.

you always will have problems with biodiesel in winter if not heated up enough.


heat up your fuel in any case.


bad injection pattern create pinging marks on the pistons like on a gas car....the rings don't like it.

[Volvoist]

Looks like few of my pistons...

[v8volvo]

No, no, no.

Please.

It's 2012 and commercial biodiesel has been around for over 10 years now. Guys, come on... the days when this was a new and confusing thing and misinformation was excusable are long over.

Biodiesel is NOT the same as vegetable oil. Biodiesel is a DIRECT DIESEL REPLACEMENT FUEL; the product of a transesterification reaction that leaves it with physical, chemical, and combustive properties absolutely unlike those of vegetable oil; a commercial fuel regulated and certified under ASTM standards, officially recognized as a road fuel for diesel vehicles without need for any modification, sold at gas stations. This is not something you are pulling out of the fryer of a restaurant or sucking out of a grease dumpster. You do NOT need to filter it or heat it -- in fact you absolutely should not, at least not any more than you would want to heat regular diesel. Biodiesel's viscosity at normal temperatures is comparable to that of diesel. In cold temperatures, biodiesel can gel, but that does not present as a viscosity problem -- rather, it presents as a filter plugging problem, the same way that crystallized diesel fuel does at slightly lower temperatures. In cold weather biodiesel is blended with winterized diesel to control the gel point, not heated. Biodiesel is not something for alternative-lifestyle folks now, it is a mainstream fuel that is used by commercial and municipal fleets, like Mike mentioned, and by private individuals who want to just put the fuel in their tank and not think too much about it. Biodiesel is *designed* so that for the most part you can do that.

Biodiesel CANNOT HURT YOUR 25-YEAR-OLD DIESEL ENGINE, it cannot explode your glowplugs and burst your headgasket, it cannot tear up your injection pump, it cannot knock your valves and pistons into each other, it cannot spray shrapnel around in your combustion chambers. It cannot, will not, and did not do any of those things. In fact it had absolutely no role in any of the damage that happened to Mike's engine.

I have used nothing but B99 biodiesel in all of my cars for the last 8 years and I don't know how many miles. That's 2 diesel VW's, and over 10 D24s and D24T's. Never a problem. I have worked in the biofuels industry and have worked on hundreds of other diesel vehicles in my line of work, everything from Mercedes-Benzes to TDI's to Sprinters to Powerstrokes to British London Taxis and more, many of which had used nothing but biodiesel their entire lives. I have seen plenty of good, bad, and ugly, but I have never seen or known of any engine failure related to biodiesel use. The reason is that it is strictly, causally impossible for it to have that kind of effect.

Many of the longevity and engine damage concerns that have been raised here are true with respect to SVO use. Biodiesel is *not* SVO and its usage is completely different. Go online and read all about it. We are living in the second decade of the 21st century and a large proportion of the diesel fuel in this country is now sold with at least 2% biodiesel in it. It's a good time for diesel drivers, even those who never use high percentage biodiesel blends, to get some understanding about what biodiesel is and isn't, and what it does and doesn't do.

So in this case, no, the biodiesel did not hurt your engine and no, it could not have even contributed to its demise. Whatever happened, it was going to happen just the same if you had had diesel in the tank instead. You don't need to worry about running it in your other diesels, and you don't need to worry about its having been part of whatever caused the problem. Let's all move out of the dark ages on this and be done with it before we embarrass ourselves.

Now.... if you had some kind of other fuel problem, such as a clogged/ruptured fuel filter, water in the fuel, etc, that could have been part of the story, especially if it caused the injection timing to run out of whack. Still doubt it, but since the circumstances of your problem are so odd and hard to understand, it is worth thinking about.... How long had it been since the last filter change, or water drain?

[michaelovitch]

hahaha very nice and true !

sorry if i 've confused

We have no biodiesel here it's forbiden by the law because can't be taxed as a petrol derivated product.

the same for vegetable oil.

little or local business doing that do not exist.



In any case the piston you saw ran only with diesel fuel from the service station.

the bad injection spray pattern did what you can see.
like the cold start device giving too much advance all the time.

the bad viscosity do that because the diesel is not sprayed but make drips wich can't burn easily and create very high pressure spots.
it's like pinging on a gas engine.

you need to readjust all parameters.


The "normal" diesel fuel is heated and cooled here on the cars : the good density and viscosity is necessary to control the quality of the combustion :

all the idi diesel from peugeot citroen range rover have electric fuel heaters and heat exchangers to heat up the fuel.

and nowadays on direct injection diesel there are fuel heaters and coolers for the same reason and because the fuel need to be cooled its at very high temp in the very high injection system (1500 to 2000 bars).

i want to stress on the fact a good fuel injection system is the key whatever the fuel you use.

you must control the viscosity injection time and vaporization because the properties change from one fuel to an other.

[ian2000t]

I have to say - very well said. On the veg oil forum they laugh about these stories of Bio-diesel exploding engines, or killing cats! It is intended to be a direct replacement for pump diesel, and can be used in cars that straight veg oil cannot (common rail, direct injection, etc).

What Michaelovitch is saying can be true of Vegetable Oil, unheated (which is what I run, but I am fully aware of the risks and will be heating it).

This whole topic got me a little bit worried though, as I have been running blends of up to 90% veg oil unheated with 10% unleaded all through this winter (with temps down to -8C). And it did get me thinking... IF biodiesel CAN do this... what can Veg Oil do??

So, I (for fun... and we all know what a fun job it is...) took all 6 of my glowplugs out last night to look for any signs of burning/melting/disinterating and check they are all still "glowing".

The first 4 are NGK's and were fitted to the car when I bought it 12 months ago - don't know how long they've been in there. The last 2 are Beru ones that I fitted about 8 months ago. They all look perfect, and all glow absolutely fine:



Sorry about the crap picture, my phone takes awful pictures up close...! So, proof that even running unheated veg oil for the last 7 months including cold starts in winter temps doesn't eat glowplugs, or cause world hunger!

[Volvoist]

I agree with George., and I suspected as much. I do think that something was wrong with my injectors. I was never happy with them after having them rebuilt with Bosch nozzles. That said, they were 1982 spec nozzles/injectors in a 1984. Apparently Bosch changed the p/n's for 1984. Why? I do not know. Did this cause my issue? I doubt it. I changed my filter ~2500 miles ago with an OE Volvo filter. I cut the old one open after a running issue I had, and it looked like brand new. I could see plenty of light through it, so I do not think it was clogged. I am still using biodiesel in my wifes Jeep Liberty CRD with no trouble, and plan to use it in this Volvo if I fix/keep it and will certainly do so in the 764TD I am picking up.

[ian2000t]

Was it turbo or NA?

I'm sure I read the early non-turbo cars were DN0SD193, and the later and turbo models were DN0SD293. Many on here are trying the GTD style nozzles DN0SD273, but the Monark version (as I have in my car).

I could imagine if you have added a turbo to an NA engine and are running the old DN0SD193 nozzles at the original pressures (NA run lower pop pressures), then you might not be getting correct atomisation which could cause your issue. I think because of the extra pressure in the cylinder from the turbo, a higher pressure is required from the injector to atomise.

[Volvoist]

No, it was completely stock, non turbo D24 in a 1984 244. As per Bosch's catalog, there are different nozzles/injector p/n's.

[anders]

Well I for one have had issues with Biodiesel NOT talking about WVO. I maintain a fleet of equipment and trucks for a small government agency. I did not have any issues with the biodiesel "killing" the engines as it ran just perfect as diesel would. We ran B99 from two different suppliers. The last supplier is a large company that is well known in the Puget sound area. The problems we ran into where that it would gel at mild temps. The company told us that the b99 was safe down to 20 degrees before it would start to gel. We ran B99 through spring and summer but when fall came around and one morning when it was about 31 degrees outside or so every diesel truck and piece of equipment in the fleet would not run. I looked in the tank of one of the dump trucks and it looked like butter. And to make matters worse the B99 did not blend well with regular diesel. I would think that all the problems have been worked out with biodiesel now. This had happened in 2007, that was the last time we ran biodiesel.
V8volvo- You seem to be well informed on this biodiesel, so at what point does the B99 gel at? Was that bad chemistry for the B99 we had or was the guy that told us that it was safe to 20 degrees full of it?

[ian2000t]

Very odd then. Don't suppose you had an EGT gauge? Mind you, if you were running too much fuel, I'd imagine you'd be getting a LOT of black smoke for damaging levels of EGT.