wrong fueling

[sprocket1]

what do I do if such a mistake should happen (putting petrol into a diesel car)? i heard alot of stories about people making this mistake ... anyone knows something about the possible damage it could cause to an engine?

 

[TR3driver]

Depends on the engine. In some cases, it can ruin the injector pump, which is muy dinero to repair. The basic approach if it does happen is to stop the engine immediately, have it towed if necessary, and clean out the contaminated fuel entirely, including all the filters etc. Then put in some fresh fuel and try to get it running again.

 

[JamesWilson]

Gasoline is much more volatile than diesel, so if you were to try and run a diesel engine on it there would be very little power- the gasoline would ignite too soon and burn too quickly where the diesel is heavier and ignites under very high compression and burns longer for the expansion stroke. The analogous situation for a gasoline engine would be if the ignition timing were set to spark before the piston reached TDC. So, running a diesel engine on gasoline is plainly a bad idea- and the injectors themselves are intended for a thicker fuel.

So if you do fill your diesel car with gasoline, do not drive it or attempt to start the car at all. Have the gasoline drained completely. If you start the car all that does is increase the number of items that need cleaning- fuel line and pump, filter, injector pump and hoses. Injector pumps are designed to run with a particular sort of fuel, too thick and it's too hard to push the stuff with sufficient force (see following comments on vegetable oil), too thin and the pump might not get the lubrication that oilier fuel provides and may overheat or wear.

You may have noticed that I've had a topic "Bio-Diesel" in the "Pub" in which I've discussed running a diesel car on vegetable oil- that fuel is much more similar to diesel than gasoline and it will work quite well in many engines during warm weather.

In running engines on vegetable oil that fuel is thicker than diesel, so then some people use small amounts of gasoline to dilute it somewhat and thereby remedy some of the cold starting/running issues involved with using that kind of fuel.

In fact, if you accidentally put a SMALL amount (say less than 5%gasoline/95%diesel- maybe more, but I'd not suggest you gamble on that) of gasoline in your diesel car it will not be affected by that, provided it's diluted to the point where the gasoline is only a small proportion of what the car runs on.

This past winter I found the vegetable oil I used wouldn't allow me to start the car- so I had to use starting ether, a very volatile gas. The car would start very easily, but there'd be a lot of white smoke and valve clatter, and with the thick oil it'd run raggedy until the car had warmed up enough. I suspect that if you tried to run the engine on gasoline excess smoke and valve clatter would be the result, though perhaps not so bad as with a 20 second squirt of really volatile gas that was then immediately burned off.

I hope this helps.

 

[sprocket1]

OK. So if anything like that happens...I am really...s****ed. :smirk: It is much easyer for petrol cars, since diesel nozle is wider than petrol one, so it is impossible to insert diesel nozle into petrol car.

 

[JamesWilson]

OK. So if anything like that happens...I am really...s****ed. :smirk:

Yes, a little petrol (like if you start and very quickly realize the mistake- say 2 or 3 liters for a 50 liter tank) probably wouldn't be too bad, but if you put a lot in and then drive it I suspect you'll damage something.

I once put petrol (40 liters- way too much to try and run it) in my Diesel car, but realized my mistake before I'd started it. Just had to push it to one side and call a garage to come get it and drain the tank. What an aggravation, but it was less bother and cost than a messed up engine.

 

[DrEntropy]

Mechanical diesel pumps count on the fuel for lubricant. Running gasoline thru one will trash it. Exploding gasoline in a diesel engine in place of diesel amounts to the same thing. BIG mess.