GODOT
Well-Known Member
I've just put 30 litres of paraffin into my fuel tank by mistake, will the engine be OK?
Is paraffin the same as diesel?
- Thread starter GODOT
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Scotty_Tradewind
Well-Known Member
It will run and probably burn the top of the piston out in minutes.
TamarMike
Well-Known Member
Evidently not the same because Diesel wouldn't burn in my hurricane lamp!
Kelpie
Well-Known Member
No, parrafin is the same as kerosene or heating oil, and I believe is called '28 second'.
Diesel is different, called variously DERV or possibly "34 second".
Diesel is different, called variously DERV or possibly "34 second".
snowleopard
Well-Known Member
It all depends what percentage of the fuel is now paraffin. If it's a significant amount I'd pump it out and put it in cans then add it back a little at each fill.
A lorry fleet manager told me diesels would run happily on something like 15% petrol which is an even lighter fuel than paraffin so a small amount shouldn't do any harm. Most marine diesels are pretty agricultural.
pugwash60
Well-Known Member
An irrelevent anecdote.
I was once running a little harbour tug which had had a small paraffin stove installed. I put out a lot of moisture which was a bad thing, so I changed it for a little diesel drip stove.
All fine so far but being mean I didn't want to waste the paraffin and thought
'what can happen it's only going to burn in a metal container'. I poured the paraffin back into the fuel tank, it seemed to burn normally. I left the boat for a now un recalled reason and time but probably a couple of hours. When I came back there was a funny noise coming from the tugs wheelhouse, where the stove was, reminiscent of a jet engine. When I got into the wheelhouse it was like a sauna, there was this jet engine type noise and the internals of the stove, which was set to minimum, was glowing cherry red. All quite exciting. Being a bit gung ho, I thought that if it had been OK for a couple of hours it probably wasn't going to change much now so I let it run on and gobble up the rest of the paraffin but it did teach me that there was quite a difference between the two.
I was once running a little harbour tug which had had a small paraffin stove installed. I put out a lot of moisture which was a bad thing, so I changed it for a little diesel drip stove.
All fine so far but being mean I didn't want to waste the paraffin and thought
'what can happen it's only going to burn in a metal container'. I poured the paraffin back into the fuel tank, it seemed to burn normally. I left the boat for a now un recalled reason and time but probably a couple of hours. When I came back there was a funny noise coming from the tugs wheelhouse, where the stove was, reminiscent of a jet engine. When I got into the wheelhouse it was like a sauna, there was this jet engine type noise and the internals of the stove, which was set to minimum, was glowing cherry red. All quite exciting. Being a bit gung ho, I thought that if it had been OK for a couple of hours it probably wasn't going to change much now so I let it run on and gobble up the rest of the paraffin but it did teach me that there was quite a difference between the two.
xyachtdave
Well-Known Member
I was filling my Merc Sprinter van up with diesel and noticed I was using Esso super unleaded (in a filthy blue nozzle). I stopped filling at 50 quid and went to pay/phone AA! The attendant reckoned it happened all the time and said a 50/50 mix of derv to petrol would be fine. I put another 40 quid of diesel on top of the unleaded to completely fill the tank and drove off (after paying!).
The tank was near empty before filling and the van ran fine on a guesstimate 50/50 split with the only problem starting took a few seconds longer. I topped the tank off with diesel after every 50 miles to get the mix back on track, kept the van for another 2 years without agro.
Don't worry about it!
jamesjermain
Well-Known Member
I'd worry. I put a litre or less of petrol in teh 64lit diesel tank of my Audi and thought I'd chance it. It didn't like it one bit although it just about ran and appears not to have caused long term harm
xyachtdave
Well-Known Member
I kid you not!
It is obviously not a very advanced engine, non turbo, 2.5 litre, 60,000 mile vintage at the time, no performance (once started) difference at all.
A litre of derv in a petrol engine is curtains however!
JustMelfort
Well-Known Member
I was told (by someone who worked for a major oil company) that you could run a diesel on home heating oil (kero not diesel) and 4% engine oil. My 1994 Landrover TDi ran on this for some time once retired to boat launching and off road use - clearly not road legal! No problem. In fact, much smoother.
Personally, I'd top up with diesel (clearly) and add the 4% engine oil because it has worked for me. Not scientific and likely to be shot down by those who know what they're talking about.
Personally, I'd top up with diesel (clearly) and add the 4% engine oil because it has worked for me. Not scientific and likely to be shot down by those who know what they're talking about.
Pye_End
Well-Known Member
I seem to remember hearing similar advice in the past - ie. it will run ok on parafin with the addition of engine oil.
CAPTAIN FANTASTIC
Well-Known Member
Paraffin is much more aggressive than diesel oil and it is only matter of time before the fuel injection pump is seized up
jwilson
Well-Known Member
A little petrol mixed in used to be common for old-fashioned diesels in ultra-cold - arctic - conditions.
I have run an old low-tech Renault car diesel on a tankful of maybe 10% petrol after an accidental fill, no obvious problems at all. On a 1998 Volvo diesel I again accidentally filled with petrol, but this time it was about 85% petrol. Drove it gently 2 miles mostly downhill to the local agents on the grounds that I'd get there before any petrol actually got as far as the injectors. Agent wanted to change absolutely everything including injector pump. Told them just to drain the tank and refill. They were obviously right as 180,000 miles later the engine died (of a non-fuel-related problem)
However i am told that the injector pumps on many modern diesels really can be badly harmed by even small quantities of petrol.
I don't really see why some diesel in petrol should do that much harm to a petrol car: it's basically oil, and many cars burn a lot of oil, and not just old bangers. If a brand new VW or Audi burns a litre of oil every 1,000 miles the dealers apparently say it's within spec. It might not run properly but I don't really see what damage it could do.
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Not true. I used Kero mixed 20 to 1 with cheapo oil for YEARS in a Landrover with no ill effects. Off road of course.
Dave
NormanS
Well-Known Member
Bog standard Diesels will run on almost anything. The handbook for an old Gardner 6L3 114hp, which I used to own stated that running the engine on paraffin was fine, but recommended adding some engine oil to the mix to help lubrication. You don't say how big your tank is, and what the resultant mix is, but if there is now a high proportion of paraffin, I would add some oil to it.
snowleopard
Well-Known Member
A different story when it comes to high-performance car diesels but boat engines are usually pretty primitive by comparison.
savageseadog
Well-Known Member
Yes, add a bit of ordinary engine oil and it will be fine
rjp
Well-Known Member
Plenty of diesel vehicles around running on used chip oil or vegetable oil from Tesco - I believe they cut it with parafin, there are recipes on the web. So maybe if you put some chip oil in it will run better?
John
John
alanabnala
Well-Known Member
Petrol has lots of inhibitors in it to stop it combusting under compression, diesel on the other hand does not! Put diesel into petrol & you lower the octane rating which could (or will depending on how much diesel there is in the petrol) lead to the normal burn process spontaneously exploding. This is known as detonation. Engines can live with detonation for a very long time, if it is not severe. It can however lead to a disruption of the boundary layer, which will increase temperature. Increased temperature leads to increased detonation,you can see where this is going, which can utimately end up with nasty melted holes in your pistons, or worse pre ignition which will totally destroy ANY engine within seconds (if that long!). The higher performance the engine the worse it will be affected. In a low compression, low revving engine, like an old lawn mower, you will get away with it, I wouldn't risk it in anything else.
Petrol in a diesel: petrol is designed NOT to combust under compression, so it won't! Hence starting problems at low to medium concentrations in diesel. The BAD thing about petrol in a modern diesel is it has bugger all lubrication and will quickly ruin the pump & or injectors. The other thing it tends to do is eat the inside of the fuel tank and lines.
I'm sure you didn't really want to know, but now you do
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Cruiser2B
Well-Known Member
My ship was going into drydock at the end of a deployment, so the engineers wanted to empty the F-44 (aviation fuel that is mostly paraffin) tanks by burning it with the F76(diesel) - diesel propulsion and generators. The Naval Engineering establishment authorized a mix of 10% paraffin; you can bet that was an extremely conservative allowance. Not knowing what 40 litres makes percentage-wise, but I would estimate you could mix up to 50% without worry and if the %age is higher then dilute or mix in some lube oil as suggested earlier.
