Stop Being Ripped Off with Diesel: DIY convert to Vegetable Oil instead

Ever since seeing it on Top Gear and ‪@vogman‬ years ago, I’ve wanted to convert our VW Caddy van to run on waste vegetable oil (WVO) but haven’t had the guts to do it. Time to change that!
In this video, we are going to attempt to exchange diesel for a fuel that’s cheap as chips: waste chip fat or other vegetable oil. Unlike running biodiesel, to switch to pure veg oil we need to make some modifications to the vehicle to avoid engine damage (LOL). I explain and show how I made simple changes to bio-tune this vehicle. As you will see, I am learning as I go, and share my blunders…
The engine in this VW is a PD (Pumpe Duse with unit injectors) 1.9L TDI, the same as in lots of cars from VW, Skoda, Audi and Seat. The exact engine code is BLS which I believe to be almost identical to the BJB, BKC, BSV, and BXE.
This experiment ended somewhat prematurely after 500 miles. The next episode will be about exactly what went wrong, fixing the engine, and the pros & cons of running a diesel engine on used vegetable oil. If you want to be notified when that’s ready subscribe goo.gl/7tFFPu and click the bell notification icon.
If you want to check out some of the parts we are using, like the heated fuel filter, heat exchanger, and big bore solenoid valves, they are available from www.biotuning.co.uk/ (no affiliation).
Note: The leaking from the 1/2" bsp fitting on the valves was a known problem with a particular batch, which has now been fixed!
Quick Links to Fuel Diagrams and other stuff:
00:00 - Into to veg oil conversion.
00:42 - Diagram explaining how a regular diesel fuel system works.
02:00 - Testing the lines to see which takes diesel to the tandem pump and which returns it to the tank.
02:30 - Changing the caddy van’s fuel filter.
03:30 - Routing the new fuel lines.
05:06 - Fitting the auxiliary fuel tank, which will become the diesel tank.
06:42 - Diagram explaining how a two-tank veg oil conversion works.
08:35 - Folly. My mistakes salvaging a lift pump.
10:03 - Where and how to break into the coolant system, to supply the heat exchanger.
11:50 - Explanation and assembly of the Biotuning heated fuel filter.
14:14 - Using the “clamptite” hose clamp method to secure the coolant hoses.
16:24 - How to wire up the electrics, namely the dashboard switch and solenoid valves.
19:12 - Testing the solenoid valves and pumping fuels between the two tanks.
19:40 - Fixing leaks with PTFE Teflon tape
21:27 - First test drive. 500-mile trip across the UK.
Lets Connect!
Patreon: / floweringelbow
Our website: www.FloweringElbow.org
FB: / floweringelbow
Music:
"Coffee" (modded slightly) by Josh Woodward, joshwoodward.com/
CC BY-SA 4.0

[@FloweringElbow]

Thanks for watching friend, I hope you are staying healthy and safe in these tough times. I am NOT a trained auto mechanic, as I am sure you can tell, and am learning loads with this stuff. This particular PD diesel isn't the easiest to convert. The follow on engine diagnosis episode is here: kzbin.info/www/bejne/hXW0mJh9oL6Dn7M I would really appreciate any feedback you have on this veg oil business. If you have done it, I'd LOVE to hear from you, and your experiences. If you liked the video, please give it a thumbs up and say hi in the comments :) Peace, Bongo.

[@chrisfleming5109]

Thanks for your reply.

[@pepejohn9307]

Yoo broski, love the vibes and message Tried to put one of these kits together, however many of the "official" sites have stopped selling parts... Would you have a specific parts list you could reveal? WvOuld be WvOnderful ! Cheers a hapus bo ti'n caru Cymru gymaint a fi 😶‍🌫

[@69bock69]

Love this vid. Want to build a mk1 or 2 golf with this. No tax , mot and cheap fuel. The dream

[@bigredinfinity3126]

3:14 use a socket to go over it when you squeeze it

[@JackButlerVideos]

awesome! can't wait for the next update video!

[@FloweringElbow]

Coming soon-ish ;)

[@COM70]

+ by tapping into the oil cooler, you get extra oil cooling as the coolant warms the veg oil. Nice !!

[@jamespeterson1148]

Right I'm off to do a broccoli conversion on my van! :D

[@FloweringElbow]

You should bro!

[@yanfishtwig2356]

Wow ive never seen that wire clamp technique looks super handy for unusual maker builds or gotafixit spots

[@simon7030]

Looking forward to follow up video about any adjustments/tweaks on your system.

[@FloweringElbow]

Hi Simon. It's in the pipeline. The weather's been too good for fiddling on the computer though. And with the lockdown, I don't get to go out in the van much... so still a little unsure of results...

[@ForEveryonebest]

Great job

[@FloweringElbow]

Thanks For Everyone :D

[@GediSpock]

Waxification in the fuel filter is often overlooked.

[@LS17EAGLE]

Great video im doing this to my Toyota yaris d4d at the weekend 👍

[@FloweringElbow]

Good muck. Let us know how it goes :)

[@be99rnm]

Nice, I bought a cheap kit a while back but never got around to using it! This kit just used a glow plug to heat the oil when cold, but eventually the heating is done with a heat exchanger and the glow plug turns off when there's enough heat from the coolant.

[@FloweringElbow]

Good morning JitsukaBlue, that's interesting. I didn't see many kits that used a glow plug like that. Yours wasn't a two tank system then? I would like to up the temperature of the injecting veg oil a bit more, as engine coolant temp is 85Cmax and veg oil reaches the viscosity of diesel at more like 120C.. But to do that AND avoid problems of polymerization and cavitation - that's the current challenge ;)

[@simon7030]

The glow plug kits were around a few years back(10 years) on eBay but didnt last(no good long term)Twin tank conversions have proved themselves long term see Biotunning website(economical kits) and ANC-Elsbett for very expensive kits.

[@audi3318]

I have no idea about combustion engines. No interest whatsoever in converting my diesel to vegan but I watched the entire video. Fantastic project and presentation 👍

[@FloweringElbow]

Hey Aud I. Thanks for the encouragement friend 🙏

[@mariapradas1717]

you have to consider that you have to change the engine oil every 5000 km because if youstart the unused vegatable oil wil come in the engine oil

[@FloweringElbow]

More good info. Thanks.

[@be99rnm]

You normally start and end on diesel...

[@FloweringElbow]

yes ;)

[@MickeyMishra]

I really wish I could just basically import a diesel version of the Chrysler minivan and bring it over here that's really what I need to do

[@7thwilliams]

Whoa ... weldone, I like a project like this, can we do this again if I buy the car & pay you for your time?

[@Dibblah1900]

Really nice conversion, thanks for taking us along! Got half way through the video, saw the copper and got a little worried (from my previous forays into biodiesel), but then you said about polymerisation! Cool. Still not sure about the glycerine problem which is why I'm not too keen on straight oil. Annoyingly, Asda about 6 months ago did 5 litre veg oil containers for 3 pounds but has stopped now. Have you found a cheap source for oil?

[@FloweringElbow]

Good morning Allan. Thanks for your message. Yes the copper is only being used to pipe the coolant, not the veg oil. Tesco seem to periodically do veg oil for 70p /l . Really, when I sort the system i want to go with filtering waste v oil. Could you elaborate on the glycerine problem you mentioned? I'm very much still learning here... Thanks again, Bongo.

[@Dibblah1900]

@@FloweringElbow My understanding is not great, but this was the reason given for biodiesel (FAME) in the first place. The glycerol backbone in the triglyceride (veg oil) does not burn as controllably as the ester. This could possibly be a low temperature issue - with condensation of side-products on the cylinder walls / piston / ... which you get past as you have by switching tanks at the beginning and end of each run. I'd really like to get to the paper 'Effects-of-triglyceride-gasoline-blends-on-and-in-a-Lakshminarayanan-Olsen' but I'm not a student and can't afford it for another side-project!

[@TheChrisey]

Maybe you could get the oil even thinner if you connect the water pipes in series going to the veggie heat exchanger right after it passes the hot oil cooler when the water will be at its highest temp.

[@FloweringElbow]

Hey Christopher, I had the same thought. The only reason I went with a parallel circuit is that I got nervous about introducing more resistance to the flow of coolant - which made be think it might over-stress the water pump (this is probably a negligible effect?). Also, unlikely as it is, any blockage in the new in series veg oil heat exchanger circuit would cause the engine to overheat. that said, the pipe routing would have been much simpler and more elegant! I'm not actually sure the cooling probably would be more efficient with an in-series arrangement? Sounds counter-intuitive but think of domestic plumbing where you put in a loop for each floor or wet underfloor heating where you might have two or three loops in a large room... Don't know the answer on that one...

[@TheChrisey]

@@FloweringElbow It's pretty much impossible to overload the water pump as it doesn't produce much pressure, unlike and oilpump/fuelpump that actually compresses the liquid, the water pump has an impeller that lets some of the water bypass it. If you end up with a clogged fuel filter heat exchanger, then the water in the rest of that channel would start boiling and probably overheat the oil eventually. However, if there are particles in the water that is big enough to clog up the heat exchanger, it will probably clog up the oil cooler too, and the radiator so I don't think that's a big concern. It's probably not gonna have any significant impact on the cooling, since the radiator is already oversized from factory, and then heat is regulated by the thermostat, but instead of getting all that heat into the radiator, you would get it into the fuel to help lower the viscosity. Indeed it's just a late night theory so it might not make much of a difference in practice

[@Anilocin]

Veg oil is probably too viscous for PD engines, the older VE engines shouldn't make too much of a fuss though.

[@chrisfleming5109]

You seem like a pretty good chap so I'm going to give you a hot tip. To save you having to modify the engine fuel system mix a gallon of super unleaded petrol with mineral two-stroke oil at a ratio of 25/1. Fill your tank with clean or new veg oil or sunflower then add a mug full or a large cup of the petrol mix. this means your engine will start instantly, run quieter than before and be slightly more powerful. the petrol does this, the two-stroke oil protects the fuel pump and no smoke out the back also for mot tests the emissions will be fantastic, better than when the car was new. Presently you can run a diesel this way legally for about 85p/liter. Keep smiling and make life more enjoyable because Boris certainly won't.

[@NicoSmets]

That is quite an undertaking. Respect. Isn't running your car on vegetable oil illegal in the UK. I'm pretty sure it is in belgium.

[@FloweringElbow]

Hi Nico. No, in the UK you are permitted a bio-fuel allowance. Once you use up that (it's 2,500l), you must declare and pay tax on the fuel...

[@simon7030]

Great video.Ive converted 4 Skoda Octavias(non PD engines) to run on veg oil using Biotunning kits over the last 12 years and save £1500 per year using filtered used oil(I pay 25p for it unfiltered)As the older cars with the Bosch injector pumps are becoming scarce(under 100K miles)I have been researching converting a PD engine(Octavia again)So it was fantastic to see your upload this morning(fantastic) The only thing that has stumped me is adding a lift pump to the new smaller diesel tank and then making each lift pump in each tank switchable or do I fit one lift pump to cover both tanks?Couldnt quite see how you were turning off your main tank pump while starting and stopping on diesel then turning off your diesel lift pump and main tank veg oil pump on?Looking forward to your follow up video.I try and change my engine oil every 4 to 5k miles.

[@FloweringElbow]

Yay! Good morning Simons, really nice to hear from a veteran veg oil user. So were the Octavias ctdi? I added a lift pump to the new diesel tank - so each tank has it's own lift pump - the main tank using the original in-tank lift pump. The silver switch, chooses which pump runs... I intend to do away with this and have it switched with a relay, that would be wired to the veg oil selector switch. That way I only have to bother with one switch, and can't accidentally have the wrong pump going (bad). Good tip on the oil change. How long did the previous engines last? Where, if you don't mind my asking, do you buy your unfiltered veg oil? ATM I have been trying to get a working system up and running with straight store bought 70p/l veg oil. Once that's working the plan's to use waste like you. Well thanks for getting in touch, Bongo.

[@simon7030]

@@FloweringElbow Thanks for reply makes sense in my head now.Next car will be a PD engine.The ones Ive done are/were all TDi's 2001-2004 with a Bosch injection pump which loves veg oil (new and used)and injectors.The diesel pump creates a strong vacuum to draw fuel from the tank so no lift pumps needed.I dont run the engine on diesel or veg with a return line the fuel is in a loop so theres less stress on the diesel pump I only have a return line for purging.So I never return hot/warm fuel to its tank.Hence when converting a PD engine I will have to return fuel back to its dedicated tank or do a modification on the in tank pump unit.My 1st conversion I did about 20k on new oil and 70k on used before unknowing to me the AGR valve/air intake to turbo got blocked so the turbo stopped kicking in.All cars since I clean the AGR valve intake staright away.My second car did about 60k on used oil before I sold it.My current one Ive done 34K on used oil.I always sourced oil off eBay and currently (lasy 5 years)buy off catering /event man who has burger van and doese events at weekend so oil has little use so is generally quick to filter and is still golden in colour.I pay 25p per 20 litres.After filtereing fat etc I reckon net is 30p per litre.Where you live you should try local hotels or similar as they would probably give it to you or pubs?I work full time so no time to get a round.I work at Costco Wholesale and currently new oil is 75p.

[@Lou1ouze]

Really nice content here. I did a small e85 conversion on an old Renault express 1.2 by cheating on the calculator temperature sensor. Engine was running but lacking of power when cold. Now I have a Peugeot Expert and an old J9 and this give me ideas, doesn't seem rocket science after all ! Where would you be looting waste veg oil ? Also I've read that the real trouble would be filtering and the place to do so. Thanks and greetings from France.

[@FloweringElbow]

Good evening Lou1oize, greetings from Wales! Thanks, it was nice to ready your comment. I'm not yet at the stage of grabbing veg oil yet. Am probably going to do the chip shop and restaurant rounds, if/when things get back to normal.

[@ESLinsider]

Cool. Around 5:40 you are cutting some holes in the tank did you just screw those faucet pieces in? Any leakage or have to use some sort of glue or silicon?

[@FloweringElbow]

Hi Ian, long time ago I know, but thanks for the question all the same. We used tank adaptors - the kind that have a long threaded part and a back nut, that screw on, clamping the plastic of the tank. We used some cut up fuel hose to make a rubber gasket/washer either side... Hope that helps. I would not like to rely on simply screwing into the plastic, even with sealing products.

[@rhiantaylor3446]

When I looked into this back in the day, one of the issues was that diesel fuel actually lubricated the diesel injection pump so a switch to Bio ran the risk of the expensive pump seizing up for the lack of that lubrication. Your much more recent van uses a completely different approach to injection but I would think there could still be a risk to injectors and/or the high pressure pump from using Bio - have you looked into this ?

[@FloweringElbow]

Hi there Rhian, Thanks for getting in touch. I did look into this. Apparently, straight veg oil actually has better lubricity properties than diesel, so can actually help in this regard... Main concern is polymerisation of oil around piston rings etc... Which I guess is the main point of the two tank conversion. Thanks for watching, Bongo.

[@hairybeekeeper5491]

Great job on the installation, nice and neat. What year is the van and what engine type is it please? - I've been looking into a similar setup myself on the ASZ engine.

[@FloweringElbow]

Good evening Hairy Beekeeper, thanks for the kind words. It is a 2005 model, one of the first of the new mk3 Caddies. It has a BLS engine which I think is almost identical to the BJB, BKC, BSV, and BXE. Is the ASZ a PD with unit injectors and a tandem pump?

[@hairybeekeeper5491]

@@FloweringElbow yes, it's the pd 130 fitted in the MK4 golf. I'm retrofitting it into an old classic car. I've read that the pd isn't suited to wvo conversions, so I'm really interested in how yours works out

[@FloweringElbow]

@@hairybeekeeper5491 I'll keep you updated. next vid is on the way...

[@vapingmonk5957]

Hi, great vid, im going to be doing a conversion to my van but bio tuning don't seem to be selling their kits any more so I've had to buy all the bits separately. Im planning on using a bosch inline fuel pump and manual valves, my question is where/how did you wire up the secondary fuel lift pump? Many thanks.

[@FloweringElbow]

Hi Dan, sorry for the slow reply. The second lift pump is wired through a relay which is in turn activated by the switch that controls the fuel solenoid valves. When diesel is selected, the relay sends current to the new lift pump that's plumbed into the new diesel tank. When veg is selected the relay is energized and the original lift pump in the main tank starts working instead. It was a while after I shot this video that I added the relay - in the video I am using a simple switch to select the lift pump....

[@vapingmonk5957]

@@FloweringElbow thank you for replying, great build by the way. How is it running?

[@mariapradas1717]

this all very nice but if you bought an mercedes with an om601 602 or 603 engine non cdi you do not have to change everthing

[@FloweringElbow]

Hi Maria, thanks for the info. Are they easy to get hold of though?

[@LS17EAGLE]

I have a veg leak from heated filter banjo (one on the side) and coolant from filter too ☹️

[@FloweringElbow]

Good luck with it.

[@madman2666]

just mix bio with diesel 40/60 oil. no mesing. a bit more diesel in winter. with a splash of kero to stop frezing. did this for years with stright veg oil

[@eddiefelson1078]

Hi FloweringElbow, great viewing. Bio-Tuning are no longer offering their kits. With plans to convert my w124 300D, have I 'missed the boat' re. duel fuel systems? Any advise gratefully received.

[@FloweringElbow]

Hi there Eddie, fortunately all has been running well with the van for the last few years (on veg oil). Trouble is that means I haven't really needed to survey the scene, in terms of suppliers etc... I think if you were determined you could do a decent conversion without a kit - I suspect you could source individual components - but it would be some work. Possibly worth it, with prices as they are ATM, if you have a source of cheap used veg oil. Let me know how it goes.

[@eddiefelson1078]

@@FloweringElbow Thanks FE. German company ATG have quoted me €800 - €900 for a system, with a waiting time of 'many months'. Not to sound lazy but.. would you have some sort of shopping list?!

[@FloweringElbow]

@@eddiefelson1078 No probs. Wow, the ATG kit sounds a lot - is it computer controlled? including injector nozzles? Anyway, I have a document that should satisfy the shopping list - but you will have to find where to get the components yourself - as it is just what was included (and how to fit) the bio-tuning kit. Shout me a coffee on ko-fi ko-fi.com/floweringelbow and leave your e-mail and ill send it you :)

[@jackjoyce1744]

Would this work on a modern Diesel engine? I’ve got a 2008 Volvo XC90 D5 would it work?

[@FloweringElbow]

Not sure TBH. Sorry for the late reply, did you look into it at all?

[@LS17EAGLE]

What size tank connectors did you use?

[@FloweringElbow]

Hey there LS17Eagle, I'm struggling to remember, I think the tank connector was 1/2" and that joins an, 8mm barb fitting that the fuel hose goes on. Don't quote me on that though....

[@joebotelho248]

How did you make to change diesel fuel tank for the boot and oil in the stock fuel tank?

[@FloweringElbow]

Hi Joe. Yes veg oil in the stock tank.

[@joebotelho248]

@@FloweringElbow was it to save money on plumbing and to choose a smallet 2nd tank?

[@FloweringElbow]

@@joebotelho248 Not really - it was so we had lots of capacity for veg oil - didn't need much diesel capacity as only used for stop and start. , so makes sense to add a small aux diesel tank. Hope that helps ;)

[@stroopi]

Hi, what’s the reference number for the solenoid valve?

[@FloweringElbow]

Hi there, sorry for the very slow reply, It doesn't seem to have anything but a Biotuning sticker on it that reads: VSV12-1.2: 3 port solenoid valve 12v, 20W, viton seals 1/2" BSP fittings

[@guyemmott4009]

Dads old car.. BX 1.9GTi 4x4 ?

[@FloweringElbow]

Spot on.

[@guyemmott4009]

@@FloweringElbow Have you done a cost analysis on Veg only mpg?

[@FloweringElbow]

Hi Guy, thanks for the question. I have not done a comprehensive one, no. I was planning to run it on waste veg oil WVO... Although the driving I have done so far, to test the system as it were, has been with new Tesco's 70p/L veg oil.

[@FloweringElbow]

My primary motivation was to see if I could make it work, and to run closer to carbon neutral.

[@bedebill]

@@FloweringElbow I tip the WVO through a old fleece jacket suspended in a old bottle crate held with luggage scrap ( cut out struts to make a hole for oil ) , this removes bits of chips, then hand pump it through 3 interlocked filter socks so it is down to 1 micron , cut a hole in a square of wood to hold the socks over the barrel. Above method is quick and cheap. Change your oil every 6 months and have a spare filter in the van all the time in case it starts stuttering have a small bottle of veg oil to prime the new filter handy. Shame your vid hasn't had more views. One thing that maybe worth considering is heating the veg oil to remove moisture , I haven't done this yet.

[@jasonga]

Mine runs on 80% veg oil as it is, it starts from cold as well.....no need to piss about with it!!!

[@FloweringElbow]

Hey Hugo, thanks for getting in touch, if that works good for you! I'd love to know more on your setup: What's the winter temp like? Are you running a TDI with a tandem pump?

[@simon7030]

When you switched to veg oil was it the right hand switch (silver one)that switched the lift pumps?

[@FloweringElbow]

HI again, yes that's right, it was the silver switch that changes lift pumps.

[@simon7030]

@@FloweringElbow Filter bag man on ebay sells filter socks.I suspend 6 in a wooden frame in a 200 gallon drum with a tap on the bottom 4 inches up attached to a pump to fill car directly or fill containers.If you dont want to buy filter bags use old jeans with the legs knotted.I turn the bags inside out and scrape out the fat once dried.You could mix with sawdust and burn on fire?I chuck in the bin.Await your follow up videos on how you get on.Thanks

[@SuperArchi2010]

Can you just put a new sun or veg oil into the tank ??

[@FloweringElbow]

Can do... should really declare and pay tax on that though, so waste is best 👌

[@FloweringElbow]

Filtered, of course...

[@COM70]

What about revenue for customs and excise ?

[@FloweringElbow]

In the UK, as a private individual you are allowed to make 2,500 litres of fuel for personal use before you need to pay tax on it. But it is an interesting question, especially as the country transitions to electric vehicles...

[@COM70]

@@FloweringElbow in Ireland, if you are dipped for fuel and their are irregularities in your fuel, the first time fine is typically €2,500. Their is no exemption/allowance for homemade biofuel or veg oil, it is illegal. If you can get commercial(licences) biofuel it is taxed at exactly the same rate as mineral oil with the exception of a €70.42 (2020) per thousand litre carbon tax which it is exempt from. Yes Ireland is very carbon neutral friendly. I wish we were more aligned with the EEC for motoring costs. It’s very expensive to own and run a car in Ireland and with almost no public transport ………

[@FloweringElbow]

@@COM70 Eeek, thumbs down to that.

[@simon7030]

Ok sorry should be public now.Same biotunning kit as your just no fuel returns only on purge.Purge is back to diesel tank so some veg goes into diesel tank but not a problem,Saves wasting diesel back to veg tank,

[@janskeet1382]

You are very cute. I can see why she likes you. 💕