Thread: Question for the diesel mechanics

So today I started up a 1983 Hilux that's been sitting outside for about 5 years.. It started instantly and idled smoothly. However as soon as I gave it some revs it ran really roughly and poured out blue smoke and almost stopped.. What could be the cause of this? Oil leaking into places it shouldn't be?

Dirty fuel? Dirty fuel lines, diesel bug?
White/grey smoke usually means a little water
Black smoke is usually over-fueling
Blue is oil.... maybe stem seals have perished/stiffened?

Might just need to run a while - as you said, its been sitting outside for a while!

I am not a diesel mechanic or any kind of mechanic but am fairly handy.

Blue smoke suggests oil. Sitting that long out in the open quite likely rings are stuck in the pistons and not sealing, water/air in fuel/hardened valve guide seals etc etc etc
Also possible rings have rusted to the bore and broken when you wound it over.
Why was it parked? did it have an issue? probably did or why would it not be started in 5 years?.
Do you want to put it back into daily use or just playing around with it?
If you want to use it I would drop the oil( I would have done that before attempting to start it and tried to turn it over by hand any resistance pull glow plugs fill cylinders with diesel and come back in a week and try by hand again) and replace with the oil filter and drain but not replace the fuel filter(you will have to replace it when all the rust from the tank that has been sitting for 5 years finds its way there.) start up and run at a fast idle till warm, take off get to 3rd run at full throttle right up to 3800rpm and pull it back down to 1800 on the brakes while full throttle the whole time and repeat till the brakes don't work(maybe 3 times?).
By now you should have a good idea if it had stuck rings and you have freed them or not or they are broken and the sump is half empty, Valve guide seals will also make it smoke if they have hardened up and could have coincided with water/air in fuel system to make run ruff/stall.

let it get up to operating temp and see what it does might of been cooked at somestage

If it's feeding itself oil, it may run away. That can be somewhat entertaining... in a very noisy and smoky way.

Originally Posted by ishoot10s

If it's feeding itself oil, it may run away. That can be somewhat entertaining... in a very noisy and smoky way.

Ha ha. Hense the term "dieseling"

Originally Posted by veitnamcam

I am not a diesel mechanic or any kind of mechanic but am fairly handy.

Blue smoke suggests oil. Sitting that long out in the open quite likely rings are stuck in the pistons and not sealing, water/air in fuel/hardened valve guide seals etc etc etc
Also possible rings have rusted to the bore and broken when you wound it over.
Why was it parked? did it have an issue? probably did or why would it not be started in 5 years?.
Do you want to put it back into daily use or just playing around with it?
If you want to use it I would drop the oil( I would have done that before attempting to start it and tried to turn it over by hand any resistance pull glow plugs fill cylinders with diesel and come back in a week and try by hand again) and replace with the oil filter and drain but not replace the fuel filter(you will have to replace it when all the rust from the tank that has been sitting for 5 years finds its way there.) start up and run at a fast idle till warm, take off get to 3rd run at full throttle right up to 3800rpm and pull it back down to 1800 on the brakes while full throttle the whole time and repeat till the brakes don't work(maybe 3 times?).
By now you should have a good idea if it had stuck rings and you have freed them or not or they are broken and the sump is half empty, Valve guide seals will also make it smoke if they have hardened up and could have coincided with water/air in fuel system to make run ruff/stall.

It was parked because it no longer had a use, it was in good running condition when parked. I'm just playing at this stage but it could see more regular use if it goes alright.
It won't rev past about 1500rpm, it just starts coughing and pouring out the smoke and then stops sometimes. It idles smoothly.

Originally Posted by northdude

let it get up to operating temp and see what it does might of been cooked at somestage

Hasn't been cooked as far as I'm aware

check the air intake for blockage

Originally Posted by kiwijames

Ha ha. Hense the term "dieseling"

Nah, that is when a petrol engine keeps running after the ignition is switched off. Caused by a lean mixture, ignition timing advanced, hot carbon deposit in the combustion chamber etc...........

This is a run away Diesel engine:

Peugeot / runaway diesel engine suck oil in the middle of the street and died there. - YouTube

Originally Posted by kokako

Nah, that is when a petrol engine keeps running after the ignition is switched off. Caused by a lean mixture, ignition timing advanced, hot carbon deposit in the combustion chamber etc...........

This is a run away Diesel engine:

Peugeot / runaway diesel engine suck oil in the middle of the street and died there. - YouTube

You sure? I always knew dieseling as oil blow back into a hot cylinder, usually via fucked ring/s. Only way to stop is to starve it of air regardless of fuel system.

Originally Posted by kiwijames

You sure? I always knew dieseling as oil blow back into a hot cylinder, usually via fucked ring/s. Only way to stop is to starve it of air regardless of fuel system.

That's a run away on a diesel. A petrol engine will not run on is own oil, but I have never tried it.

Roger

Originally Posted by northdude

check the air intake for blockage

+1

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2l engines are pretty bullet proof. Blocked fuel filter will make it run slow under load but have minimal effect no load,blocked air filter will make it hard to start (same effect as a flat battery or weak starter motor)smooth idle but rough at 1500rpm suggests to me it isnt running on 4 ,the lumpy running and smoke suggests unburnt fuel from cylinders not firing. This can be due any number of reasons but mainly a lack of compression .I would leave it running a while to see if it clears its self but if youve done the normal things like changing filters,draining the old fuel(diesel bug) and its still faulty you will need to dig a bit further. Firstly bleed the injectors and check fuel delivery to each. The injectors on 2l are a pintle nozzle and pretty rugged but can fail if blocked with crud. The injector pump can be erratic if left unused and the o rings and seals fail especially on older units that were run on high sulphur fuels from the 80,s and 90,s.You can normally see fuel seepage from the pump top housing and side fittings. This normally doesnt cause erratic running but I have had an occasion when it did. A kit of orings seals and gaskets fixed the fault. Remove the radiator cap and run give a few revs,check for bubbles in the water(this can mean a head gasket failure between cylinders and water jacket,but not always) Under no circumstances add water to a hot engine even when running as this will crack a 2l head instantly(the thermostat housing dumps directly to the cylinder head) If after all this the fault is still there then you will need to do a compression test. At this stage you can expect things to get expensive.