Why do Engines Sometimes Burn Oil?
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- เผยแพร่เมื่อ 3 มิ.ย. 2024
- Sometimes, engines consume a lot more oil than they should. Why? There are many causes, including lubricant volatility, bore polish, leaking seals etc. So let's take a look.
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2:25 bad valve seals…source of the good old “Bowtie Salute” (aka the “Chevy Salute”)
Just found your channel and been watching videos. Great stuff, man. Thank you.
Couple other possible reasons for oil consumption could be: 1) Sticking oil control rings that no longer push against the cylinder wall well enough due to running crummy oil too long, and 2) A badly designed PCV system that sucks too much oil vapor into the intake manifold, which would become worse if the oil volatility is high.
He did mention that their other rings on a piston. As he explained the compression rings are the last line of defence for oil entering from the crankcase. The oil rings are the first line, but the do not completely eliminate oil from passing them, even when in good condition.
With aircraft engine, one of the reasons they have dual spark plugs is incase one fowls due to oil consumption (as well as redundancy for lead fowling, coil loss and other reasons). My understanding is that air cooled engines especially those with steel cylinders and aluminium pistons suffer from increased oil consumption due to larger cold clearances (and other reasons). Not tested yet, I imagine oil consumption would be severely reduced with a turbocharged engine, even if just slightly, as there will never be a vacuum in the combustion area. The positive pressure differential would also stop oil entering the valve guides most likely. Of course you have the possibility of oil entering from the turbo if the oil return was to become restricted. Just rambling. A lot of the aircraft engines either get fowling or hotspots because of oil ingress, so the topic of keeping it out is important to me. A lot of these engines are naturally aspirated still so they do not have the benefits of the pressure differential. I was thinking of having a fine white filter after the aftercooler to capture and assess any oil that gets through the turbo, haven't seen that done, but Im sure it has been in testing facilities. I'm also surprised that gapless rings are not more commonly used on engines. Thanks for the video. When My patents come In I'll help you out.
In cars generally turbocharger engines burn more oil because the ring gaps are much larger and tolerances not as tight to accommodate additional thermal expansion when on boost.
Modern cars use unleaded fuel and run ultra lean by design the plugs tend to stay clean. Typically where you see fowled plugs in a car its a symptom of another issue (e.g. injectors not operating correctly, engine fuel condition incorrect, plug electrode gap incorrect.)
Even with a turbocharged gasoline engine, there will still be a vacuum during the intake stroke almost all the time since the engine is only going to be in boost under higher loads such as when accelerating somewhat hard. Diesel engines are somewhat different since they don't need a throttle plate, but you still won't be building much if any boost at idle. A diesel engine which uses a throttle plate for emissions reasons may regularly pull a vacuum during the intake stroke. But as someone else said, turbocharged engines tend to have larger piston ring end gaps and looser piston to cylinder wall clearances so the pistons and rings don't bind from the thermal expansion when in boost, so in practice, turbocharged engines tend to burn more oil.
Good picture of ring twist, function, during strokes. Word is, Top & second rings are slightly different?
Top, more compression holding? Second ring, doing some, (backup) compression? A bit more, oil control?
Major, oil control, of course, the lowest, oil control ring. You could do pics of these, in another vid?
Here's a thing. In the ongoing drive, for better fuel economy & reduced emissions -
Thinner oils & lower piston ring tension, have been used, to reduce frictional losses. Ok, when pressure above,
'Cos pressure firms the ring, against the cyl wall.
On the suction stroke, not enough tension, against cyl, wall? Vacuum draws oil up :)
Depends on the engine, but yeah often the second rung will be a bit of a hybrid. I think the second point you’re generally making talks to the idea of lower viscosity oils being more volatile. That is somewhat the case, although it’s probably been offset by the fact that most of the engine oils are now Group IIIs and so have fewer light ends.
@@LubricationExplained Lower vis oils do not have to be more volatile - The reason, you stated.
I meant, minute amounts of liquid, lower vis oil, can get sucked up past the rings, to go above the piston, during the suction stroke.
Similarly, minute amounts of oil can get sucked down the inlet valve, seal & stem, during the suction stroke,
The latter may help, to clean the inlet valve, for GDI's?
Over the service interval, these causes, consume engine oil?
Carbon formed & blowing by, down the piston rings can deposit in piston grooves?
May help seal? A little? But also, hinder rings function? To the greater loss?
very well explained!
Glad it was helpful!
Thank you very much for this lecture. Indeed, you are a doctor in this field. But I have a question, please, dear. What is the alternative solvent for sulfur acid in the setting of the bitumen?
I don't think your question is lubricant related? Maybe I'm wrong.
Could you share a bit more on what you are trying to achieve?
Thanks
Ond of the main reasons is = clogged piston oil drain holes.
Toyota 2AZ-FE
BMW N52b25
If it s not too late, these can be unclogged using 3 oil flushes with BG EPR 109
If the compression, the crankcase ventilation and the valve seals are ok, could it be the oil rings that are worn/damaged which are the reason that the engine uses a lot of oil? The engine in my car has been run hot/overheated once by the previous owner.
As a apprentice 50 years ago was told by a mechanic when fitting compression rings with a cutout groove think of sex ... When you're in you're up and when you're out you're down.
Manual book says I should use 5w30 oil.
The engine has direct injection and turbo, plus with my city's temperature reaching 40 c, and constant traffic, my car consume oil 1 liter / 2000 km.
Do u think i can change into thicker oil auch 5w40?
Pretty hard to give a recommendation without specifics. But in general going up a single viscosity grade doesn’t hurt too much.
Might increase oil consumption as well if the higher viscosity stops the oil rings scraping the piston as completely.
Air temperature doesn't matter in modern cars because the cooling capacity is vastly oversized, if you want an engine to run slightly cooler just change the thermostat. That said it might also use more oil if the engine isn't operating in the optimum windiw because the cylinder wouldn't be properly sealing.
I habe question..Can engine running with high coolant temperature causes oil consumption?
Hello everybody,
I 'm wondering if it is possible to soak in some cleaner into the cylinders through the spark plugs holes,let it work awhile and run the engine to working temperature , would it benefit to free those piston rings ?
Just an idea I had one day after looking Inside the cylinders while changing my spark plugs.
Thanks for getting back to me.
Tigo.
The piston rings should remain clean if oil is changed at the correct intervals and injectors are operating effectively.
In high mileage engines people sometimes resort to high mileage oils which have a heavier weight. Ultimately only a rebuild will rectify the issue however.
@@thomas316 hello,
Thanks for getting back to me .
Will help me with my reflection.
Thanks
Nice
You forgot oil via PVC system, oil being pushed into the intake manifold due to exissive blow-by due. Moreover, blow-by caused by a combination of upper cylinder ware, espicaly at the pistion thurst side, during the power-stroke event, and pistoin ring were.
All theise add up to a total ware.
Another problem is that the piston rings stick to tbe piston and don't excert enough pressure against the cylinder wall, due to lack or extended oil changes. Actualy all the possiblites of exssive oil consumption are mostly due to lack of and/or not enough or extending oil changes.
Some time's due to bad MFG design or metalogy on engine block or piston ring or a combination of both.
One more valve gide ware is another source of oil consumption.
He did mention cylinder wear. Also, its PCV, not PVC. A PCV is also not a component that is required or crucial for an engine to operate and not all engines have them. You could also state, turbos, superchargers, oil coolers, heat exchangers, gaskets, manifolds etc
I have to wonder if using a product like CRC intake valve cleaner will wash the oil out of the cylinder walls causing increased rate of wear. Anybody have any idea if it does?
Ive always used it on my GDI 2.0l engine. It could damage the catalyst more than anything, I use it before ever oil change, your best bet is to let it soak longer, and drive it really hard after until you feel the cat get kinda clogged, then a huge release of white blue smoke comes out the back for 5 minutes. Get ready for a smoke show. I tried all GDI cleaners, so far im using the Seafoam GDI cleaner. It smoked more than the other brands.
@@chandlerchhem2128 You realize that smoke doesn't indicate cleaning, right?
@@averyalexander2303 yea the best one I prefer is by CRC. It helps take care of the GDI system
PCV VALVE???
your voice is too slow to catch . . . i suggest to please keep your volume increased
Thanks for the feedback.
Usually its because they are Mitsubishis
Mazdas say HA-HA!
Possible oil consumption route number 3: your engine is a spawn-of-satan 2 stroke and burns all its oil, by design. Curse the darned things!