Bleeding a diesel engine

Musicmaker · Jul 16, 2013

Got talking to a bloke today at Tesco's while getting diesel. Long story short, I mentioned that I was running on fumes and glad that I did not have to bleed the engine if I had run out of diesel. He told me modern diesels don't need bled as the are self bleeding. When I got home, curiosity got the better of me, so checked the engine for a lift pump but could not find one.

Is he correct? My thinking is that since there is an electric fuel pump in the tank, I would still have to bleed each injector as normal. What's your verdicts?

Billy

crashbox · Jul 16, 2013

I seem to recall modern diesels are self bleeding but I wait for more opinions.

Datatek · Jul 16, 2013

Musicmaker said:
Got talking to a bloke today at Tesco's while getting diesel. Long story short, I mentioned that I was running on fumes and glad that I did not have to bleed the engine if I had run out of diesel. He told me modern diesels don't need bled as the are self bleeding. When I got home, curiosity got the better of me, so checked the engine for a lift pump but could not find one. Is he correct? My thinking is that since there is an electric fuel pump in the tank, I would still have to bleed each injector as normal. What's your verdicts?

Billy

Supposedly self bleeding but if there is enough air in the lines it's necessary to crack the feed line to the FIP and bleed the air out of the line and sometimes it's also necessary to crack the injector unions.

flat · Jul 16, 2013

i once ran a hire car diesel out, all i did was fill it up from a jerry can and it worked again. I didnt know at the time that running diesels out could be a problem. Now i try to not go below 1/4 tank just to be safe - i do a lot of long commutes and dont want to get stuck in traffic and run out again (as happened in the hire car)

matt1987 · Jul 16, 2013

Most new diesels are meant to be self bleed as per datatek but most will need help bleeding as when cracking engine to purge system of air it can do twol things:
1 - flatten the battery
2 - overheat the starter motor
And still not start and can in some circumstances bring on the eml with a host of fault codes.

gfromleeds · Jul 16, 2013

My old 03 vectra 2.2 diesel was a right royal bitch when it ran out took nearly 2hours of almosr constant cranking (on jump leads) before it started dont know if there was a fault somewere but i msde sure it never ran out again

Datatek · Jul 17, 2013

Common rail diesels (M57) do not need bleeding as far as I know, indeed I don't think there is an easy way to manualy bleed them apart from the pressure check point on the common rail.

JohnnyCrash · Jul 17, 2013

Also even if it does start again once ran dry expect it to start leaking fuel as the seals don't like being dry!

wammers · Jul 17, 2013

Unless the engine is cold pre 99 models will struggle to self bleed in the event of running out of fuel. Because the fuel lift pump does not run on cranking. That is when you will find out just how good your battery is. Post 99 should not be a problem. The injection pump will always self bleed providing the lift pump is running. The high pressure pump in the injection pump will blow any air out through the tank return. However if the injection pipes are empty as in the case of removing and replacing them, they will NOT self bleed unless they are cracked at the injectors. Pipes should be full if you run out of fuel so that should not be a problem. But best advice would be, DON'T run out of fuel.

TCubed · Jul 17, 2013

Doesn't running out of fuel cause problems with drawing up all the rubbish from the bottom of the fuel tank? Or is that only with old engines?

dizzytim · Jul 17, 2013

gfromleeds said:
My old 03 vectra 2.2 diesel was a right royal bitch when it ran out took nearly 2hours of almosr constant cranking (on jump leads) before it started dont know if there was a fault somewere but i msde sure it never ran out again

Vauxhall's don't have a in tank fuel prime pump so if you run out you need to hand prime fuel to high pressure pump to get it running, they can be hard to get going again

wammers · Jul 17, 2013

TCubed said:
Doesn't running out of fuel cause problems with drawing up all the rubbish from the bottom of the fuel tank? Or is that only with old engines?

Fallacy. The fuel is always drawn from the bottom of the tank so any **** in there will be drawn out, old, new, full or empty.

Mamasbigtruck · Jul 17, 2013

Mine was a bitch to bleed. I would have said a good 15 mins of cranking

Primed to FIP connection by powering lift pump.

I eventually removed glow plugs and span it over with injectors loose until they leaked then tightened down. I had manifold off and it engine spins over better

glow plugs back in and freshly charged battery then it started.

Thor1950 · Jul 17, 2013

Mamasbigtruck said:
Mine was a bitch to bleed. I would have said a good 15 mins of cranking

Primed to FIP connection by powering lift pump.

I eventually removed glow plugs and span it over with injectors loose until they leaked then tightened down. I had manifold off and it engine spins over better

glow plugs back in and freshly charged battery then it started.

loosen the fuel line nut going to injectors. have some turn it over when fuel comes up tighten them one at a time. it will start to run on 2 in a few seconds all will fire. Had a farm tractor and when we ran out of fuel a 5 minute job to get it running again.

Bleeding a diesel engine

Musicmaker

Active Member

crashbox

Well-Known Member

Datatek

Well-Known Member

flat

Well-Known Member

matt1987

New Member

gfromleeds

Well-Known Member

Datatek

Well-Known Member

JohnnyCrash

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wammers

No longer with us, RIP

TCubed

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dizzytim

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wammers

No longer with us, RIP

Mamasbigtruck

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Thor1950

Well-Known Member

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