duncan
Active member
How much petrol can a diesel engine take in the mix and why?
INHOOTF (in the humble opinion of the forum)
INHOOTF (in the humble opinion of the forum)
a petrol diesel mix...
- Thread starter duncan
- Start date
jimmie
N/A
When I was a tank driver in the Red Army we used to put 15% into the diesel in the winter to stop it freezing and then drink the rest. Presume that's why you wish to do it?
Col
New member
Not too much.
With the advent of ULS diesel, the lubricating properties of diesel have already been compromised, petrol will wash away more lube from vital areas such as injector pump.
Did you make a mistake at the fuel pump??
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With the advent of ULS diesel, the lubricating properties of diesel have already been compromised, petrol will wash away more lube from vital areas such as injector pump.
Did you make a mistake at the fuel pump??
<A target="_blank" HREF=http://www.arweb.co.uk/argallery/colspics> Cols Picture Album</A>
adarcy
New member
Re: As Col says
Pre low sulphur 10-15% no real problems except some loss of power and was done regularly to reduce the waxing point in winter.
Now with ULS diesel and especially if you're talking new tech (cdi) car engine, stay below 10%. Diesel is a good lubricant and the actual fuel injected is the ONLY lubricant to the injection pump (easy to visualise as a little engine pumping the fuel into the real motor if it's an inline but same principle with a rotary pump). So the pump can score very easily if run on petrol or a low lubricacy diesel/petrol mix.
However, if you have just sploshed petrol into a diesel tank and were unable to start it or only ran < 1 minute, I doubt v much if any real damage has been done. But drain tank ASAP and fresh clean diesel in quick.
Anthony
Pre low sulphur 10-15% no real problems except some loss of power and was done regularly to reduce the waxing point in winter.
Now with ULS diesel and especially if you're talking new tech (cdi) car engine, stay below 10%. Diesel is a good lubricant and the actual fuel injected is the ONLY lubricant to the injection pump (easy to visualise as a little engine pumping the fuel into the real motor if it's an inline but same principle with a rotary pump). So the pump can score very easily if run on petrol or a low lubricacy diesel/petrol mix.
However, if you have just sploshed petrol into a diesel tank and were unable to start it or only ran < 1 minute, I doubt v much if any real damage has been done. But drain tank ASAP and fresh clean diesel in quick.
Anthony
hlb
RIP
I once accidently put petrol in an artic unit. As some one said. We used to put a bit of petrol in, in places like Austria or futher East. To stop the diesel from freezing. But anyway. Thats another story. Now back to the point. The trouble is. Petrol rises to the top of the tank. So back to the time when I put some in accidently. I filled it up to the top with diesel. All seemed OK till I was coming up the M1 in the dark and the tank was getting empty again. It was quite exciting. The flames out the exhaust looked very impresive. Just like some think out of Thunderbirds!!
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Haydn
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Haydn
duncan
Active member
so - to recap-
1. petrol floats on diesel
2. really old style engine less effected than newer
so why would a reengined V8 blow a head gasket because of some diesel in the tank when being run up for the first time?
not mine..........but a big issue
1. petrol floats on diesel
2. really old style engine less effected than newer
so why would a reengined V8 blow a head gasket because of some diesel in the tank when being run up for the first time?
not mine..........but a big issue
paulineb
Active member
Mr B knows all about diesel/petrol mix. He put petrol in his diesel Discovery - hee hee
Pxx
Pxx
Col
New member
<<so why would a reengined V8 blow a head gasket because of some diesel in the tank >>
Er, was it diesel with petrol in tank, or petrol with diesel in tank??
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Er, was it diesel with petrol in tank, or petrol with diesel in tank??
<A target="_blank" HREF=http://www.arweb.co.uk/argallery/colspics> Cols Picture Album</A>
hlb
RIP
yes. To get to the Nitty gritty you really do not want. Diesel in the petrol or petrol in the diesel. Arguments in between withstanding.!!!!
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Haydn
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Haydn
jleaworthy
New member
Put petrol in my diesel car tank on one occasion - about 20% of tank contents. Added a bottle full of Redex upper cylinder lubricant. Car is still running fine 40 K miles later.
adarcy
New member
Re: Ah !
Like everyone else, had thought you meant a bit of petrol in diesel setup.
Now some diesel in petrol setup, hmmm, perhaps diesel didn't atomise because of much lower injection pressure - no ignition with the spark and then hydrauliced and blew the head gasket ? Sounds plausible to me and v convincing if I had rebuilt someone's engine and they did it and expected me to rebuild it again for nothing I'm afraid.
Like everyone else, had thought you meant a bit of petrol in diesel setup.
Now some diesel in petrol setup, hmmm, perhaps diesel didn't atomise because of much lower injection pressure - no ignition with the spark and then hydrauliced and blew the head gasket ? Sounds plausible to me and v convincing if I had rebuilt someone's engine and they did it and expected me to rebuild it again for nothing I'm afraid.
duncan
Active member
Re: Ah !
no I did mean petrol (left in tank possibly) mixing with new diesel added to tank for new diesel V8 engine replacing old petrol V8 volvo...............
no I did mean petrol (left in tank possibly) mixing with new diesel added to tank for new diesel V8 engine replacing old petrol V8 volvo...............
Col
New member
Re: Ah !
S*m**i ?? ( as in sword)
<A target="_blank" HREF=http://www.arweb.co.uk/argallery/colspics> Cols Picture Album</A>
S*m**i ?? ( as in sword)
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brianrunyard
New member
Re: Ah !
You say possibly a little petrol left in tank. What are we talking about, a cupfull, a couple of gallons, what?
How much diesel?
If it's only a little petrol in a lot of diesel, shouldn't have blown the head gasket.
Brian
http://homepage.ntlworld.com/brunyard
You say possibly a little petrol left in tank. What are we talking about, a cupfull, a couple of gallons, what?
How much diesel?
If it's only a little petrol in a lot of diesel, shouldn't have blown the head gasket.
Brian
http://homepage.ntlworld.com/brunyard
adarcy
New member
Re: Oh Dear!
As before - "as Col says"
if it is/was an anagram of " iarumaS " then I think the kindest advice is to do a search on it. "Other people" have warned repeatedly about some diesel V8's that have serious problems.
If I/Col am/are wrong, what sort of %age petrol/diesel was in the mix?
Anthony
As before - "as Col says"
if it is/was an anagram of " iarumaS " then I think the kindest advice is to do a search on it. "Other people" have warned repeatedly about some diesel V8's that have serious problems.
If I/Col am/are wrong, what sort of %age petrol/diesel was in the mix?
Anthony
G
Guest
Guest
If excessive / any, petrol is in mix the liners and pistons are "washed" of lubrication usually available to them from the diesel. Rings stick,piston stops, conrod pokes out of block. Is that an oversimplification or what?
Regards
Rob
robinwdunham
Regards
Rob
robinwdunham
brianrunyard
New member
But as the original question asked.
Should it have blown the head gasket?
Brian
http://homepage.ntlworld.com/brunyard
Should it have blown the head gasket?
Brian
http://homepage.ntlworld.com/brunyard
hlb
RIP
Well. If running diesel engine on petrol. You should have blown the whole boat apart probably. How do we know what percentage of petrol/diesel was being delivered to the engine at the time. It does not mix very well.
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Haydn
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Haydn
duncan
Active member
glorious sense...
I think you have probably hit the proverbial on it's head with that Haydn.
Oh well it' s all going to have to go to the lawyers as solutions are a long way away from everyone
thaks to those who contributed - and yes it involves a sword; but now is not the time to look back at what might have been!
I think you have probably hit the proverbial on it's head with that Haydn.
Oh well it' s all going to have to go to the lawyers as solutions are a long way away from everyone
thaks to those who contributed - and yes it involves a sword; but now is not the time to look back at what might have been!
