Today by mistake I filled up with 60lt of unleaded the tank had 20lt of diesel in it. I traveled about 100 k to where I was going turned motor off when I tried to restart it would not fire long story short had car towed to my mechanic. has anyone else suffered this problem and how did it work out
Unleaded fuel in diesel tank
- Thread starter Cajun
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Black Tonka
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Oh man! I hear that unleaded can do bad things to a diesel motor but I am not sure what exactly would happen. Hope a well experienced forum user here will have information. Hope the damage is minimum for you! ..
joshman
Member
If the motor didn't go bang, then you might be alright. Basically, you'll definitely need to drain the tank and bleed out your fuel lines, probably flush them out with some kind of cleaner. Maybe even need to flush the fuel pump, injectors and cylinders.
Diesel engines rely on compressive force and heat to ignite the fuel and thus provide the force for the cylinders, compression is usually around the 17:1 mark.
Petrol engines rely on the explosive and volatile nature of petrol to provide that force. Compression is much lower in a petrol engine, 4:1 maybe?
So if you take an explosive fuel, and place it under the massive compressive force of a diesel engine... You tend to blow the head off your diesel block or something like that.
Diesel engines rely on compressive force and heat to ignite the fuel and thus provide the force for the cylinders, compression is usually around the 17:1 mark.
Petrol engines rely on the explosive and volatile nature of petrol to provide that force. Compression is much lower in a petrol engine, 4:1 maybe?
So if you take an explosive fuel, and place it under the massive compressive force of a diesel engine... You tend to blow the head off your diesel block or something like that.
joshman
Member
gazza414 said:
To be honest, I put together what I know of diesel and petrol engines (not a lot) and extrapolated an outcome.
However with a bit of research, my outcome is off the money.
Have a read of this http://www.straightdope.com/columns/read/2179/can-i-use-diesel-fuel-instead-of-regular-gas
Either way, putting petrol through a diesel system is very bad. The op should have. It gone anywhere and got the truck towed, it might have worked out cheaper in the long run. After reading that article, I would suspect the fuel pump has seized. And that's an expensive fix.
Tappet
Member
That's bad news cajun. What sort of engine is it? Either way the most likely damage will be to the fuel pump and the injectors. Rest of the engine will probably be ok.
BTW Josh, petrol burns similar to diesel. In the combustion process there is a flame front not an explosion. Infact the auto ignition point of petrol is higher than diesel.
BTW Josh, petrol burns similar to diesel. In the combustion process there is a flame front not an explosion. Infact the auto ignition point of petrol is higher than diesel.
diesels are anything from about 14:1 to 22:1 compression. i think the D40 is about 15:1. petrols anything from about 7:1 to 14:1.
diesels don't always burn with a nice flame front. especially egr equip engines.
but none of that matters all that much. diesel engine will generally survive running on petrol. its the injection system thats the problem.
petrol has less/no lube in it so injection system tends to wear very quickly when running on petrol. however with common rails they tend not to pump up much injection pressure when running on petrol and the ecu won't let the engine run as there is not enough fuel pressure. this can actually save the injection system. so hopefully all you need to do is drain the tank and injection system and refill with diesel.
i would also throw in some 2 stoke oil as theres usually a little bit of petrol left in the lines etc.
clean it out and see how it runs. if your lucky it will be fine.
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joshman
Member
Tappet said:
yeah, found that in my research also. As I now understand it, the problem might be that the petrol DOESN'T ignite in the cylinder and is thrown into the exhaust system where it might ignite, which would be pretty nasty I imagine.
But yes, pump and injectors. Probably rooted. Need magical Unicom power to fix. (sorry. At work and bored as f**k)
robmacca
Member
A mate I know did this in his 200's Diesel Cruiser.... He went 200kms b4 it just stopped..... no bang, nothing...... but $18,000 later it was back on the road.....
I hope things turn out better/different for you.... This mistake has become VERY Common these days with more and more car type diesels + alot of Servo's are now adding more diesel pumps next to the Petrol ones and people just accidentally pick the wrong handle up and start filling
I hope things turn out better/different for you.... This mistake has become VERY Common these days with more and more car type diesels + alot of Servo's are now adding more diesel pumps next to the Petrol ones and people just accidentally pick the wrong handle up and start filling
joshman
Member
I always double check I've got the diesel handle before pumping. It'd suck to have this happen.
And the worst thing you can do is drive it anywhere!
And the worst thing you can do is drive it anywhere!
D
Dave
Guest
14 to 1 compression ratio in a Petrol. What in ?
It would be pinging its heads off.
9-10 to 1 compression ratio is the average these days in a petrol.
As for diesels, around 18 to 1 is the average these days.
Direct injection motors dont need as high compression. Plus you can run higher boost aswell.
Indirect injected donks like the QD32 and TD27 etc run 22 to 1 compression ratio's.
They make more torque down low then a Di motor running say 18 to 1 compression.
Tweake already knows this, just clearing some things up.
Injectors are like $1000 each in Common rails, Insurance should pay for the damage.
johnbritto
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no good deisal has a higher flash point than petrot also the comments about lubrication are 100%right fuel pump and injectors will probably be stuffed and id be worried about pistons as well check out ebay i seen crate engins there for about 6 grand and as for the pump im sure you will be able to kit and reseal i thinh you will get new injectors for about 200 each either way im sure you will never do it again
the new lean burn direct injected petrols. sorry can't remember what one it was. petrol and diesel tech is getting closer and closer.
Cajun, the diesel is really a simple engine. It doesn't have a butterfly valve like a petrol engine does to restrict the airflow, it just gets complete lungfuls every time.
How they work is the ECU commands the injectors to inject fuel and the injectors open, fuel is squeezed into the combustion chamber and the pressure causes the fuel to ignite.
If you aren't getting the engine started, I'd check the following things:
1) How much fuel rail pressure is there while the engine is turning over?
2) Are the injectors making any sounds at all?
3) Does your CEL (Check Engine Light) work (test by NOT starting the car) and does it come on?
4) Can you smell diesel in the exhaust?
5) Is your primer bulb firm after 5-6 squeezes?
6) Has your mechanic checked your glow plugs? Are they coming on?
How they work is the ECU commands the injectors to inject fuel and the injectors open, fuel is squeezed into the combustion chamber and the pressure causes the fuel to ignite.
If you aren't getting the engine started, I'd check the following things:
1) How much fuel rail pressure is there while the engine is turning over?
2) Are the injectors making any sounds at all?
3) Does your CEL (Check Engine Light) work (test by NOT starting the car) and does it come on?
4) Can you smell diesel in the exhaust?
5) Is your primer bulb firm after 5-6 squeezes?
6) Has your mechanic checked your glow plugs? Are they coming on?
Dave, many cars these days run higher than 10:1 theoretical CR..many bikes now run 12 to 1 and higher off the shelf.
I run a race bike with 18:1 theoretical CR and its not a diesel
People get hung up on theoretical CR's and the bigger picture is quite different
Cajun , all the best with getting the motor running again
I run a race bike with 18:1 theoretical CR and its not a diesel
People get hung up on theoretical CR's and the bigger picture is quite different
Cajun , all the best with getting the motor running again
WTF ??? that does not make much sense.
more than likely pump can't make enough pressure so ecu will not fire injectors.
D
Dave
Guest
Dave, many cars these days run higher than 10:1 theoretical CR..many bikes now run 12 to 1 and higher off the shelf.
I run a race bike with 18:1 theoretical CR and its not a diesel
People get hung up on theoretical CR's and the bigger picture is quite different
Cajun , all the best with getting the motor running again
I know they can run higher then 10, but 10 to 1 is pretty much the average.
What fuel do you run in the bike ?
