And if so what is the process involved and is it a good or bad thing.
Fitter was smelling the oil he was draining out and I asked what the hell you doing and he said “seeing if it’s making oil” I nodded like I knew what he was talking about. But I dont 
Discuss…
Only thing I can think of is that maybe he thought water was getting in such as blown head gasket which would dilute the oil and make more of it.
But then I haven’t really got a clue what I’m talking about
Yes,
On an older engine, with leaking injection and worn rings, unburned diesel can make its way into the sump.
When the level rises high enough, the mix of oil and diesel can work its way back into the combustion chamber.
The results are spectacular and potentially really quite dangerous…the engine will rev to destruction. Shutting the engine off won’t help because it’s not running on fuel from the injectors any more but what’s in the sump.
There was a long-running thread on this last year, where someone refused to believe it could happen.
Various videos were posted.
Was he smoking at the time ?
…and no , its not good for you 
.
Looking/smelling for impurities within the engine oil.
Smelling for excess diesel wash and burning and `froth’ making (condensation/coolant mix).
All are gauges of engine wear and tear.
GasGas has described it very well
I’ve heard of new diesel cars making their ‘own oil’. Apparently when the DPFs are doing a re-gen, the excess diesel used to do the burn off can end up going into the sump if the enging is switched off before the re-gen is complete and cause the oil level to rise, risking engine failure. He may have been sniffing for diesel in the oil.
GasGas:
Yes,On an older engine, with leaking injection and worn rings, unburned diesel can make its way into the sump.
When the level rises high enough, the mix of oil and diesel can work its way back into the combustion chamber.
The results are spectacular and potentially really quite dangerous…the engine will rev to destruction. Shutting the engine off won’t help because it’s not running on fuel from the injectors any more but what’s in the sump.
There was a long-running thread on this last year, where someone refused to believe it could happen.
Various videos were posted.
Haha yeah the most contentious thread on TNUK ever lol
It used to happen on older engines with mechanical fuel lift pumps that were often bolted to the crankcase or (Gardner) to the injector pump. The diapraghm could split letting diesel leak into the sump, a leak on the injectors could do it as well as some engines had them beneath the rocker cover so a leak wasn’t visible. First thing the driver would notice was the level rising on the dipstick.
Pete.
GasGas:
Yes,On an older engine, with leaking injection and worn rings, unburned diesel can make its way into the sump.
When the level rises high enough, the mix of oil and diesel can work its way back into the combustion chamber.
The results are spectacular and potentially really quite dangerous…the engine will rev to destruction. Shutting the engine off won’t help because it’s not running on fuel from the injectors any more but what’s in the sump.
There was a long-running thread on this last year, where someone refused to believe it could happen.
Various videos were posted.
Soon to face the wrath of bking for saying all that
Of course, he might just be some sort of pervert who likes sniffing used engine oil.
norb:
GasGas:
Yes,On an older engine, with leaking injection and worn rings, unburned diesel can make its way into the sump.
When the level rises high enough, the mix of oil and diesel can work its way back into the combustion chamber.
The results are spectacular and potentially really quite dangerous…the engine will rev to destruction. Shutting the engine off won’t help because it’s not running on fuel from the injectors any more but what’s in the sump.
There was a long-running thread on this last year, where someone refused to believe it could happen.
Various videos were posted.
Soon to face the wrath of bking for saying all that
I can take it.
And if he still maintains it can’t happen, I know a bloke with an old Daihatsu FourTrak he might like to buy! 
GasGas:
Yes,On an older engine, with leaking injection and worn rings, unburned diesel can make its way into the sump.
When the level rises high enough, the mix of oil and diesel can work its way back into the combustion chamber.
The results are spectacular and potentially really quite dangerous…the engine will rev to destruction. Shutting the engine off won’t help because it’s not running on fuel from the injectors any more but what’s in the sump.
There was a long-running thread on this last year, where someone refused to believe it could happen.
Various videos were posted.
Hmmm, and their’s me thinking that only happened when the turbo oil seals blew, you learn something new every day.
Anything that introduces an uncontrolled quantity of flamable fluid or vapour or dust into a diesel will do it.
Rudolph Diesel’s first engine put its cylinder head through his outhouse roof when it O/D’d on coal dust!
inventors.about.com/library/inve … diesel.htm
It nearly took its inventor’s head with it.
Its called a runaway and I saw it happen. One of our old Leyland tankers was refueling a Phantom in Cyprus. The fumes from the avtur was sucked into the air intake. Old gardner engine, revved out of control until it grenaded. You can shut it down by letting off a co2 extinguisher into the air intake but we didnt find that out until afterwards.
Stuff the fire extinguisher malarkey, I wouldn’t like to be in the immediate vicinity or anywhere near even in the event of a runaway engine.
this happened to me in a 4 series 17 years ago. mazda 6 2.0diesel where fond of doing it aswell before blowing up.
I was under the impression all you had to do was block the air intake with something. Easy on a car, just use an old rag, but more difficult on a truck.
Could try stalling it I suppose.
If BKing is reading this, watch this
merc0447:
And if so what is the process involved and is it a good or bad thing.Fitter was smelling the oil he was draining out and I asked what the hell you doing and he said “seeing if it’s making oil” I nodded like I knew what he was talking about. But I dont
Discuss…
Injectors leak diesel when they get older . Its common The oil level goes up and gets watered down by fuel . New injectors fix it
bazza123:
Could try stalling it I suppose.
IIRC the general consensus was that you’d be more likely to smash the gearbox up than stall a truck. Something along those lines anyway.