a Td5 question for the gurus......

[DEFENDERZOOK]

if i was to drive from sydney to victoria.......in my Td5 fender......
since its all downhill......the engine will be in overdrive....that is foot off the throttle on the downhills......


this situation stops the injectors from fuelling to improve engine braking......
what effect will the lack of fuel have on my upper cylinders.........

as they wont have any fuel....there wont be any lubrication......will there.....?

[catch-22]

I would have thought that the crank splashing in the oil is all it would need....

edit: oops, just realised it was meant for gurus and you were probably after more then that.....

[DEFENDERZOOK]

the crank shouldnt splash in the oil......if it does....it will aerate the oil and reduce its lubricating efficiency.....


the crank is lubed by oil being pumped in through the oil galleries and through to the bearings....and then allowed to run back down to the sump.......


the combustion chamber does not have any lubrication other than the fuel entering the cylinder.....
unless the rings are worn or the valve guides are leaking......in this case you will have engine oil lubricating the cylinder......

this is visible to the naked eye.....as a blue smoke screen emitting from the tailpipe.......

[vnx205]

......... as they wont have any fuel....there wont be any lubrication......will there.....?

Only the same lubrication as a petrol engine, I suppose.

[Slunnie]

Does LPG lubricate the upper cylinders on LPG engines? If there is no combustion I would have assumed that there would be residual on the walls that would remain there. I don't think people have had a related problem when driving to Victoria before.

[vnx205]

if i was to drive from sydney to victoria.......in my Td5 fender......
since its all downhill......the engine will be in overdrive....that is foot off the throttle on the downhills......


this situation stops the injectors from fuelling to improve engine braking......
what effect will the lack of fuel have on my upper cylinders.........

as they wont have any fuel....there wont be any lubrication......will there.....?

Does it completely shut off the fuel?
Is that a feature of the TD5 or do other diesels do that too?

[DEFENDERZOOK]

so its just as safe heading to victoria as it is brisbane......?







i was just curious as im in overdrive situations quite a bit......
injected engines all do this.....

the old style carby motors were constantly sucking in some fuel.....giving some sort of lubrication at all times.....

[cwebb]

I've often wondered about the fuel shut-off in my TD5 manual Disco as well.
After hopping on the ferry over to Tasmania, I drove up Mt Wellington, next to Hobart. Over 1km high, obviously its all up-hill from the bottom.
After parking at the summit for 1/2 hour (yes it was freaking freezing), the temperature guage ALL the way down the hill did not come back up to operating temperature. As I was coasting down the hill the whole way, in 2nd-3rd-4th gear with zero throttle, obviously I was not in any way working the engine.
I suppose if my vehicle was an auto, then the engine may have been on idle and actually used fuel. However it is my belief that with a manual, even if it is only minimal, that the TD5 uses sweet bugger all of fuel on fast idle with no throttle.
Cheers everyone.

[29dinosaur]

so its just as safe heading to victoria as it is brisbane......?

From Sydney: Uphill to Brisbane? Downhill to Melbourne?

[Tank]

the crank shouldnt splash in the oil......if it does....it will aerate the oil and reduce its lubricating efficiency.....


the crank is lubed by oil being pumped in through the oil galleries and through to the bearings....and then allowed to run back down to the sump.......


the combustion chamber does not have any lubrication other than the fuel entering the cylinder.....
unless the rings are worn or the valve guides are leaking......in this case you will have engine oil lubricating the cylinder......

this is visible to the naked eye.....as a blue smoke screen emitting from the tailpipe.......

The Combustion Chamber in most diesels is in the top of the piston and requires no "oil Lubrication" the cylinder walls and the underneath of the pistons are lubed through oil squirters either from a hole in the con rod or oil nozzles in the crankcase aimed up at the pistons, no damage through "lack of oil lubrication" will occur because of deceleration. Many diesel engines suffer from fine cracks in the heads usually running from the injector nozzle to the valve seats. A lot of this damage is caused by working the engine hard, say up a long hill, with a load and then coasting down the other side, which cools the combustion area very quickly. It is good practise after a long hard (hot) haul up a hill to actually drive down the hill instead of coasting with no throttle, it stops the head from cooling rapidly, Regards Frank.