Oil consumption ?

[Fummins]

Cobrajet - I agree with you. Not a big deal. I wonder though, I'm guessing the means of burning oil is likely through piston-piston ring / cylinder bore wear, and oil making its way up past the piston rings. Or through the valve guides. It doesn't really matter, I just wonder if maybe Fummins might have a guestimate through his engine tear downs, if he might have been able to tell.

I've only torn apart my engine that spun a rod bearing. I have a couple 2017 engines on the floor waiting to opened up. One had almost 500k km(too lazy to convert), and the other one had maybe 240-340k kms and was knocky.

I don't think we'll be hearing from cobrajet for a while

[7milesout]

I didn't catch that the rest of the thread was 2 years old. I wonder what old Cobrajet done went and done to go to the slammer.

[Fummins]

https://mirageforum.com/forum/showth...posed-attacker!

[7milesout]

I remember reading that thread. I must have read the first post or maybe 2. The last couple posts were not there at that time. I remember thinking when I read that, that it couldn't have actually been Cobrajet. Kind of shocking that it apparently is.

And yes, if that had been GA or FL, Cobrajet would at least have a much lower bail, or maybe no bail. Especially so since he has a clean record, and cooperated with law enforcement. I'm just speculating here, but it sounds like from the linked ad, that the father instigated the incident, and may have instigated the physical altercation. And if so, if CJ felt in danger of his life or serious injury, he would have been justified to defend himself how he did.

I'm a big guy like the father. And I could do some serious damage to someone if I got enraged. But I dang sure wouldn't do so unless I felt threatened.

[Eggman]

Cobrajet - I agree with you. Not a big deal. I wonder though, I'm guessing the means of burning oil is likely through piston-piston ring / cylinder bore wear, and oil making its way up past the piston rings. Or through the valve guides. It doesn't really matter, I just wonder if maybe Fummins might have a guestimate through his engine tear downs, if he might have been able to tell.

Any way to tell by using a borescope camera to inspect the combustion chamber?

[Grumpy Bear]

When I changed my oil at 100,000 miles (5,000 miles since my last oil change), my oil level was 1/2 a pint below the "full" hole on the dipstick. This is with 5W30 Mobil-1 synthetic.

So my 100K mile engine is consuming about 1 cup of oil in 5,000 miles. I'm OK with that. I don't think I noticed I was using any oil between oil changes until my car had more than 75,000 miles.

Remember that the amount of oil represented by the 2 holes on the dipstick is only a pint...

Attachment 21918

From the design engineering viewpoint, 0.03% to 0.05% of fuel consumed would be a 'normal' oil consumption target. Most OEMs won't do a thing until this is closer to 0.25%. Even call it normal. Normal it isn't.

Oil control starts getting lost when the drain back and expander in the oil ring plugs with oil oxidation products. 60 to 80K miles seems to be setting a pattern.

Yes, many will say. I have 250K on mine and it uses no oil and some with 30K are already in trouble. This is an environmental difference. That is, different in every way. OCI length. Engine use. Oil chemistry. Filtration. Weather. Load and so on.

[Grumpy Bear]

Hi guys i have an 2015 1.2 5 speed with 65,000 miles

lately it seems like its beginning to consume oil pretty rapidly. Not exactly sure how much but i have to top it off midway between oil changes or it will go below the add hole on the stick. Started over the last 10k miles or so.

Anyone else having this issue? Did it lead to anything bigger, or get worse as time went on?

I realize this is a really old post, but the answer will not change. This is most likely the result of an accumulation of oxidation products and degraded fuel polymers collected in the oil ring and its land. Not the rings wearing out. Not in 60K miles anyway if you've been half smart about oil maintenance.

See, the thing is in the world of oil, detergent doesn't mean what you think it means. Okay, functionally it is similar but opposite, but unlike your favorite laundry detergent it cannot remove deposits nor even prevent them. Just like it can't remove all stains. What it can do is slow the rate at which they build up.

In practical terms this means that deposit will form once a significant level of antioxidants/dispersants have been consumed and the only way to defeat this for most off the self-oils is shorter oil change intervals. Since SAE class SM ZDDP has been on the decline and while you normally think of this as a wear additive it is also a powerful antioxidant. Meaning while OEM's have been pushing longer OCI's, the oil is begging for less.

[foama]

I realize this is a really old post, but the answer will not change. This is most likely the result of an accumulation of oxidation products and degraded fuel polymers collected in the oil ring and its land. Not the rings wearing out. Not in 60K miles anyway if you've been half smart about oil maintenance.

See, the thing is in the world of oil, detergent doesn't mean what you think it means. Okay, functionally it is similar but opposite, but unlike your favorite laundry detergent it cannot remove deposits nor even prevent them. Just like it can't remove all stains. What it can do is slow the rate at which they build up.

In practical terms this means that deposit will form once a significant level of antioxidants/dispersants have been consumed and the only way to defeat this for most off the self-oils is shorter oil change intervals. Since SAE class SM ZDDP has been on the decline and while you normally think of this as a wear additive it is also a powerful antioxidant. Meaning while OEM's have been pushing longer OCI's, the oil is begging for less.

This is well observed in Europe, particularly with some Toyota and other makers engines. The Daihatsu/Toyota 1KR series engines for example.
They are built to last practically for ever, but some will prematurely burn more and more oil because eventually the oil-scraper piston ring will become fully caked up and be of no function any more. Hard black carbon will fill the groove with the contracted piston ring, the drain-holes in the back of the caked-up groove fully clogged too. The reason for all that being bad and saturated cheap quality, usually mineral-based oil being left in the engine for far too long.

If you scimp on oil quality and don't change it often enough, you may as well throw your money out of the window!

A good and perfectly suitable oil doesn't have to be any well advertised over-expensive stuff either.
I change it every 10 to 15 000km with an excellent 0W20 fully synthetic oil that costs around €6.- (US $6.-) a quart.
I recently opened the valve cover to check play, and the insides was perfectly clean, no brown residue, no nothing. It looked like brand new.

[sunbeam]

Have noticed when using redline with the label saying "extra zddp" additive has been burning slightly more oil.

Burned from top hole to middle of the indicator in 3,500km.

Granted, this was with some trailer towing as well but I would believe that there is something with the zddp additive that makes it burn a bit more.

Anecdotally a friend with a toyota tercel sees the same oil burning with the redline oil compared to others.

With molygen I do not see as much oil consumption.

[Grumpy Bear]

Have noticed when using redline with the label saying "extra zddp" additive has been burning slightly more oil.

Burned from top hole to middle of the indicator in 3,500km.

Granted, this was with some trailer towing as well but I would believe that there is something with the zddp additive that makes it burn a bit more.

Anecdotally a friend with a toyota tercel sees the same oil burning with the redline oil compared to others.

With molygen I do not see as much oil consumption.

ZDDP levels have nothing to do with consumption. Okay providing you don't run it out of antioxidants and dispersants often enough to foul the rings.

What does have an impact is viscosity, HTHS, and volatility, NOAK. Ring seal and evaporation.

That's from the oils contribution.

Operating conditions weigh heavy on this as well. More load, more usage.

Oil's viscosity sensitivity to fuel dilution is also a player.

Lastly, mechanical condition. Speaks for itself.