safe to fill up diesel engine from empty?
Posted by Cool_Present_6513@reddit | askcarguys | View on Reddit | 32 comments
hi i'm a first time diesel owner and the gauge said I had 40 miles left in the tank... however when I restart the engine, it turns but doesn't start and now it seems i have no fuel. So my question is it is safe to fill up from empty? Will I need to call anyone or can i just go ahead and fill up?
Smokey_McDoob@reddit
Never, ever, EVER fill up from empty. The fuel tank is single use only. Ignore the filler port on the side of your car! /s 🙄
Do you really think there's THAT much difference between a gas engine and a diesel? There are differences, sure. And there are no dumb questions. But there are some that should be.
ProJoe@reddit
On some diesels, even modern ones, you might need to manually prime the system after running out of fuel.
They have a valid question and you're shitting on them. There are no dumb questions, period.
Smokey_McDoob@reddit
To be clear, any diesel engine will eventually self-prime, if you run the starter long enough. Obviously not good for the starter (or battery), but still smarter than asking if one should not fill an empty fuel tank.
I stand by my comment.
Personal_Chicken_598@reddit
I’m not sure I’d say that. Quite a few won’t prime without starting aids like ether or cracking lines.
Personal_Chicken_598@reddit
Yes you probably will need to do that.
But the first step of that is to make sure you have fuel in the tank. And it really doesn’t matter if that a full tank or 1/4 tank
Competitive_Cheek607@reddit
Yes, but if there’s air in the high pressure fuel system you may be cranking for a long time until the air is bled out. Anecdotal, but a friend’s F-250 7.3 was stolen and driven till it ran out of fuel, it took a looooong time cranking but once it started it ran fine thereafter. However, that was the end of his starter. There’s really not anything else a mechanic or anyone could do besides put fuel in the tank and try to start it. You might try turning the key to “ON”, so all the way forward but just short of starting it (if this is a push-button car, press the start button but don’t press the brake pedal), do this a few times. Some cars prime the fuel pump when the key is on, if yours does that will help provide fuel from the tank to the high pressure pump on the engine, but some cars won’t run the fuel pump unless the it sees the engine is rotating
LankyNihilist@reddit
That's not true at all. The system can be bled, when that is done properly it will start immediately.
Competitive_Cheek607@reddit
Describe to me how you would bleed a high pressure fuel system without the high pressure pump turning, which only happens when the engine is turning?
Personal_Chicken_598@reddit
I’d run it on ether until it started to run on fuel. But I dont recommend an amateur do this. It is possible to complete blow up your engine doing it
Vegetable_Log_3837@reddit
In my duramax I would pop the bleed screw on the fuel filter, then pump the manual pump until fuel comes out. Tighten the bleed screw. Should start up after a few seconds of cranking.
Without doing that you’ll kill the batteries before priming the fuel system.
LankyNihilist@reddit
You said there was no way to start it other than just trying to start it. You didn't say anything about bleeding the system by turning the engine over.
Competitive_Cheek607@reddit
Buddy you’re the one who said it can be bled “properly” and you haven’t told me how
LankyNihilist@reddit
I'm not here to do a full write up on bleeding a high pressure diesel system. There's google for that. What I did say was that your statement is incorrect.
Competitive_Cheek607@reddit
I offered help to OP and a little explanation, you argued but can’t even prove your point, because you’re arguing about things you don’t understand. I’m a mechanic, and if we both are one of us shouldn’t be
LankyNihilist@reddit
Ok pal clearly you're the end all be all expert. Let me bow down to your great and powerful knowledge.
SpaceCat72@reddit
Fuel level is no real issue, if you lost prime, different engines have different ways of re establishing prime. Some will crank till primed and running, some require pumping to bleed air from the fuel system. Hopefully your owners manual will address this.
Hard_Head@reddit
Sometimes the fuel filter needs to be primed.
One_Evil_Monkey@reddit
Depends on what it is.
Need to find out if there's a manual pump at the fuel filter. If there is, use it to prime the system. If not, then you should find the bleed proceedure for your specific vehicle.
Otherwise you run the risk of killing the battery, burning up the starter, or possibly even burning up the pump.
vtmiller1969@reddit
I don’t understand, how would it not be safe? Million cars a day fill up from empty.
One_Evil_Monkey@reddit
Diesels are a little different. They use high pressure compared to gasoline. If they're run dry, they usually need to be bled or you run the risk of burning the pump out.
amanke74@reddit
You could do all the extra steps that everyone else is saying or you could just send it.
overheightexit@reddit
Safe? As opposed to dangerous?
B777X_787-9@reddit
What car do you have for
Dismal_Language8157@reddit
not 100% safe, there is a possibility you might have a heart attack and die while filling up. Id just risk it and fill it up anyway, just saying its not 100% safe, probably 99.98% safe. up to you
B777X_787-9@reddit
🤣🤣
Infinite-Past7640@reddit
On our heavy equipment, if we ran out of fuel, it was quite a procedure. Bleeding line, priming lines, fuel filters,,, our mechanics usually took care of it inside of 30 minutes.
I’m the one who fired the guy who let the fuel run out.
jibaro1953@reddit
If it doesn't start with added fuel, you'll need to bleed the fuel lines.
Simple enough, but a two person operation.
One person loosens the nut holding the fuel line where it enters the cylinders while the other person c r anks the engine. When the fuel shows up, tighten the nut and the engine should start
Thereelgerg@reddit
What other option do you think there is? Do you think running a tank dry totals the vehicle?
JP147@reddit
Nothing wrong with filling it up completely, but it may not start easily if there is air in the fuel system.
You will likely need to bleed or prime the fuel system. How you do this depends on the car, your manual should tell you how.
CameronsTheName@reddit
Don't fill it up all the way. Put 20 litres in it.
First off check in the engine bay. There should be a big filter with 2-4 hoses coming out of it. Does that filter have a big button on top ? If so, push that button down 30 times and see if it gets hard. This is a manual hand primer. If there's no button I guess you skip that step, most small cars don't have a manual primer.
Cycle the key into the on position and back off 5-10 times (don't crank the car) this will cycle the pump and push fuel from the tank up to the filter in the engine bay and hopefully up to the injectors.
Once you've cycle the keys a few times give it a crank. Crank for no longer than 30 seconds, give it a 1 minute rest and crank again for 30 seconds, give it another minute then crank again for 30-60 seconds.
Cranking it any longer will burn the starter motor out and can be a costly repair.
If it doesn't start, a mechanic will need to inspect the car and bleed the fuel system. Hopefully the fuel pump hasn't had any excessive wear. Diesel fuel pumps and injectors usually use the diesel as lubrication. When you run them out of diesel they can fail.
jackedupfarmer@reddit
What kind of engine? It will likely crank for a bit but a modern diesel should get on relatively fast
ScaryfatkidGT@reddit
Can’t hurt to try…
If they doesn’t work the tho how system need’s to be bled