Rolled tractor restart

[quazz]

I had been reading a thread about a guy who rolled his tractor on its side and starting it after it was righted may have caused serious engine damage. I didn't know this was an issue and prior to reading this if I had rolled my tractor on its side I would have tried starting it immediately after righting it. I certainly would not do this now after reading that thread but have been thinking about why this engine damage occurs and how do you eventually get the tractor going again.

 

[old and tired]

Oil gets passed the rings on the pistons and fill the cylinders. Oil doesn't compress in the cylinders and the piston arms bend. Leave it up right for a long time or pull the glow plugs or injectors... turn the engine over slowly by hand.

 

[North Idaho Wolfman]

Old and Tired nailed it!

 

[mickeyd]

When I rolled mine, it was on it's side for less than an hour.

I waited till the next day before re-starting it. Everything was fine and that was over 5 years ago and haven't had any problems.

 

[quazz]

Thanks gyys. So would a motorcycle be the same? Or say a chainsaw?

 

[greenacresnorth]

Thanks gyys. So would a motorcycle be the same? Or say a chainsaw?

motorcycle is dependent on how long it was on its side, if you drop it and stand it right back up then no harm, happens to me on the regular doing stupid crap with a adventure bike. now if it fell and laid on its side for a few hours or a day, i would definitely pull plugs before starting. Chain saw is a totally differant ball of wax, 2 stroke motors dont hold very much oil in the crank case, infact two stroke gas motors can run in any orientation as long as they dont have a float carb, hence why your chain saw will run upside down or sideways all day long. If you want to see a good example of oil seep on a 4 stroke engine, look up some videos of aircraft radial engines. you will notice that any time a round engine is started cold, engine is rolled over by hand then rolled 3-4 revolutions on the starter before fuel and spark is hit, this builds oil pressure but also clears the bottom cylinders of oil.

 

[Fordtech86]

Gas engines can do it too. And as far as chainsaws, a 2 stroke engine wouldn’t have engine oil in the crankcase to leak in past the rings.

 

[SidecarFlip]

Gas engines can do it too. And as far as chainsaws, a 2 stroke engine wouldn’t have engine oil in the crankcase to leak in past the rings.

Only fuel mix.....

 

[Russell King]

There are now small 4 stroke engines that lubricate like a 2 stroke so have no crankcase oil. They burn the 2 stroke fuel mix.

That is just an interesting development in engine design to me. I assume it has been done to eliminate oil spillage and allow for operation in any orientation like the 2 strokes now.


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[Fordtech86]

Only fuel mix.....

Yes but not a significant amount.

 

[lugbolt]

some will leak past the rings but that amount is generally insignificant except on smaller diesels. The major issue lies in the closed crankcase ventilation system. The crankcase is vented. It has to be per federal emissions regulations. Gone are the draft tubes, so initially they vented the crankcase via the valve cover and oil separator directly to the intake manifold on non-turbo diesels. So generally the tractor (or engine or whatever) gets turned over, then oil is dumped into the valve cover. With the vent tube going directly to the intake manifold, the oil that gets into the valve cover also gets into the intake manifold; and in a lot of cases, a LOT of oil (the entire crankcase's lube oil sometimes). Then as the engine is turned over via starter, oil gets pulled in through the intake valves, the cylinder can't deal with it, the flywheel weighs 50 lbs, starter has a ton of torque and boom, bent rods and broken pistons. It don't always happen but I'd say 75% of the time, maybe more often. I've even seen head lifted from the block in an extreme case. Just makes a big mess.

The tier 4 engines (and now tier 5) have a different style vent system; lot less likely but it still happens. On a DPF tractor if you get oil into the DPF, you will be removing the DPF for cleaning, or in some cases, replacing it. They do not deal well with engine oil. Plugs them quickly. On these, if it's been turned over, engine damage, it can cost a LOT of money. This is also why proper maintenance is crucial on a DPF equipped tractor.

If the engine's turbocharged, the crankcase vents pre-turbo. So if that tube from the valve cover gets full of oil, it goes directly to the inlet side of the turbo, sometimes it destroys the turbocharger, sends pieces of compressor wheel into the engine, bends valves, etc. If lucky, it might have an intercooler, so the oil and parts get stuck in the cooler-replacement only (along with the tubes and hoses).

If you do turn it over, do not try to restart without removing either the injectors or the glow plugs (preferably injectors). Then once they're out, turn it over by hand a bunch of times using the fan to spin it. You have to get ALL of the oil out. Some of them are next to impossible to get to the injectors or glow plugs, some are easy. I did a 3901 last week takes about 3 hours give or take just to get TO the injectors (and glow plugs), then just a little longer to get them out. They're all different in that sense.

 

[GeoHorn]

Turning a hydro-locked engine over by hand first is a good idea.

But until it is spun quickly, such as by the starter, it’s unlikely much of the fluid will be evacuated out of that spark plug or injector hole.

If the piston is brought up to TDC and a suction hose is placed into the cylinder one might find success in pulling any fluid that is actually pooled inside that cylinder, then when they’re all considered evacuated, spin the engine by the starter to expell the rest.

Just my opinion (and worth every penny too!)

 

[North Idaho Wolfman]

until it is spun quickly, such as by the starter, it***8217;s unlikely much of the fluid will be evacuated out of that spark plug or injector hole.

Not true actually with a Kubota Diesel, I think you would be shocked if you could see how little space is left between the piston and head, think layers of paper.

So turning it by hand you will evacuate almost all the oil, or enough not to do damage.

I turn them by hand first then with the injectors still out I spin them with the starter, anything is there gets spit out in a quick hurry and your good to go.

 

[GeoHorn]

...
I turn them by hand first then with the injectors still out I spin them with the starter, anything is there gets spit out in a quick hurry and your good to go.

That last action is the one I thought so important. Thanks for the education.