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HappinessNow
July 27th, 2009, 02:01 PM
What would happen if someone puts Unleaded Gasoline into a Diesel Engine?

issih
July 27th, 2009, 02:15 PM
In the olden days not a lot...flush it out and you would be ok.

Nowadays...not so good, the clever fuel injection systems that have made diesels so much more useable do not like unleaded at all.

The standard advice if you do this and realise in time is NOT to start the car, call a garage to come collect the car and have them flush the fuel and the lines ASAP. IF you get the fuel going into the injectors you are probably looking at a fairly big bill.

Sorry if thats not welcome news :s

ajgreeny
July 27th, 2009, 02:56 PM
Happened to me many years ago, and no problems followed on. The car was even driven on petrol (gasolene) until it suddenly coughed and stopped, and the realisation of what had happened dawned. The car was towed to a garage, fuel drained and flushed, refilled with diesel fuel, and away it went, a pretty expensive mistake to make even then with the cost of the fuel and flusing etc etc.

However, this was many years ago, and I know that is no longer the case. Deisel engines are very much more sophisticated now and great damage is done to injectors, particularly in common rail diesels, and also oil seals. So whatever else you do and as issih says, DO NOT START THE ENGINE, or you're in trouble big time and big cost.

gcvisel
July 27th, 2009, 03:13 PM
What would happen if someone puts Unleaded Gasoline into a Diesel Engine?

I can't say, but I can tell you what happens when you do it the other way around! My wife filled my 67 Mercedes 230 (gasser) with diesel ("Aren't ALL Benzes diesel?") and got about two blocks before she coughed to a stop in a cloud of white smoke! No real damage, as I had it towed home and sucked all the diesel out and put it in the real diesel Benzes. The first tank after that was still pretty smokey, but we lived it down.

:-)

Spook

gloscherrybomb
July 27th, 2009, 03:17 PM
I put 10 of diesel in to my 306. Didnt want to pay to get it drained so I filled the rest up with petrol. Coughed and spluttered for a couple of days but fine in the end.

ajgreeny
July 27th, 2009, 03:25 PM
The 306 is a pretty old design diesel, though, and I think you would be in trouble with a newer Peugeot.

niteshifter
July 27th, 2009, 03:48 PM
Hi,

Depends - a lot - upon how much diesel was present before the gasoline was added.

"Best case" scenario, 90% of tank volume present is diesel, 10% or less gas added:
Fairly safe, but add more diesel to the tank, burn (or siphon) a couple gallons - add a couple of gallons. You'll be fine. You've taken some few hundreds of hours of operation off some of the parts, but as lifetime operating hours (aka hours to rebuild) is measured in thousands - it's not a big deal.


Next scenario, mostly empty, less than 10% volume in tank of diesel, tank filled with gasoline:
Initially what's delivered to the engine is a gas-oil mix. This will get you a few miles (15 - 30 minutes) with little damage. But as the engine runs on it will be getting more gas than diesel. Which is a bad thing for modern injectors as mentioned in the post above. It gets worse: Diesel ignites by being compressed. Gasoline doesn't do so well at this, mostly it will swill around in the combustion chamber and flush the the lubricating oil away, accelerating wear on rings and cylinder walls. At this point we're moving from expensive damage to very expensive damage (complete rebuild). Usually with this extreme gas to diesel ratio the engine just stops limiting the damage to the injectors. You've taken more hours off the parts than the "best case" but you'll still have thousands left. Just don't restart and go, coaxing it to run, call a mechanic and tell 'em what happened.

The greatest risk - the worst case - comes from ratio of fuels being closer to the last situation above than the first one as the engine will continue to run and wearing rapidly, sometimes to the point of lockup, lifetime hours can drop to a thousand or less.

Swagman
July 27th, 2009, 03:51 PM
As a truck driver who regularly put a few gallons of petrol into the diesel tank each winter it really depends on how great the mixture is.

If you have put a couple of gallons into a tank mostly filled with derv then sod all will happen..Might run a bit hotter.

If, however, you have filled mostly with petrol.... MUPPET

Time to get the syphon hose out !! (except most newish cars are fitted with anti-syphon devices).

You obviously did not notice that the fuel nozzle was loose in the fuel mouth of your vehicle.

They make diesel nozzles larger so people can't make the mistake you made to petrol engines which is the way it usually happens.

HappinessNow
July 27th, 2009, 04:30 PM
it's actually someone I know that picked up a rental truck, it appears that whoever turned it in before them probably put water in the tank to save money on the refuel charge.

gletob
July 27th, 2009, 07:22 PM
it's actually someone I know that picked up a rental truck, it appears that whoever turned it in before them probably put water in the tank to save money on the refuel charge.

People are just stupid.

lisati
July 27th, 2009, 07:28 PM
it's actually someone I know that picked up a rental truck, it appears that whoever turned it in before them probably put water in the tank to save money on the refuel charge.


People are just stupid.

True: one would hope that people would have at least a basic appreciation of the difference between fuel and water.

stuartziane
April 30th, 2010, 11:55 PM
Just so happens I am a marine diesel engineer :-)

Basically, you could run a diesel engine on a mixture of petrol (gasoline) and diesel at a ratio of 10:90 max. In areas where it's VERY cold, you can use either Kerosene or Petrol to help improve the operation of the engine.

The problem is NOT with damage to injectors, pumps or seals, it's damage caused by the shock waves from the very sharp rise in pressure when the petrol is injected into the cylinder. Petrol doesn't particularly like being subjected to the resulting temperatures and pressures of a compression ratio of 25:1 (for example)! The resulting damage will most likely damage the bearings, the piston, and you may even blow a head gasket (which is designed to be the weak point so that it blows rather than anything else) Modern cars won't like it because they quite often utilise multi-shot injection. This means that prior to the main fuel charge, a smaller charge is injected to prepare the cylinder (raising the temperature and reducing the ignition delay). If you consider the advanced injection timing, and what will essentially a 'rich' fuel mixture... You can probably tell it's not going to be good!

However, if you get the mixture of petrol and diesel right, it does actually have it's benefits.

I hope this helps :-)

swoll1980
April 30th, 2010, 11:57 PM
It will be fine. It's just going to cost a small fortune to have it flushed out.

Kai69
May 1st, 2010, 12:13 AM
If you want a laugh,, I work as a mechanic for a family firm have owned it since 1972 garage and workshop we took over selling Isuzu pickup trucks the first time my boss filled it up yep you guessed it with petrol so we had to push it from the forecourt to the workshop :P He was very red in the face.

philinux
May 1st, 2010, 12:30 AM
If you want a laugh check the thread date.

Raising the dead.