[suoiruc]

I'm a simple guy....any amount of oil consumption that makes me need to add more in between changes is what I consider 'high'. It doesn't make sense to me how an oil change interval within the objective effective range for a given oil would make a difference in oil consumption...am I missing something there?

I’m not exactly sure what you’re asking but if you mean, “why would a change in interval from 4k miles extended to 8k miles, consume more oil” then, I would guess because the oil has degraded and thinned out, allowing more oil past the rings. In other words, it consumes more oil in the last 4k miles than the first four. Is that what you were asking?

 

[FormInFunction]

If you do an oil analysis & the quality of the oil is acceptable both at 4k miles and 8k miles then it is still within it's objectively effective range (not what the manufacturer states, not what ppl themselves believe). So if it is still working effectively then it makes no sense to me that the amount burning would be different.

If the oil has thinned out then it is no longer 5w-30 & thus no longer in it's objectively effective range. If its picked up too much contamination from blowby, etc then the same logic applies. That's my question (if that made it clearer at all).

 

[suoiruc]

If you do an oil analysis & the quality of the oil is acceptable both at 4k miles and 8k miles then it is still within it's objectively effective range (not what the manufacturer states, not what ppl themselves believe). So if it is still working effectively then it makes no sense to me that the amount burning would be different.

If the oil has thinned out then it is no longer 5w-30 & thus no longer in it's objectively effective range. If its picked up too much contamination from blowby, etc then the same logic applies. That's my question (if that made it clearer at all).

Assuming that the oil is performing properly over the entire 8k mile range, then I would conclude that the oil consumption is engine caused and that the consumption should be consistent; in theory. No oil analysis has been done so I can’t explain why it seems to be using more oil latter in the interval other than what’s been said. Maybe it’s just a new norm for this car and the future consumption will be more consistent but I have to take into consideration other factors such as high summer temps, and how hard the car is driven, etc. And I’ll try to monitor it more closely, paying attention to the color, and when it begins using oil to determine the best change interval. It might even be considered normal giving the mileage and why I asked for data. Thanks to everyone who contributed!

 

[Sisyphus]

It's often wise to error on the safe side. 2.5 to 3k oil change meets that sage old saying. But your car your money and your walking shoes if the thing prematurely wears out. Good luck with it.

 

[FormInFunction]

That sage old saying was on sage old oil. With the synthetic stuff is pouring money down the drain changing it at those same intervals unless you're doing HPD. Independent 3rd party oil analysis has even shown the oils succeeding in their claims for 20k miles of protection. I still change at an interval which is probably too short of where it should/could actually be but thats because I also tend to be resistant to change...and the 2zz is high revving so I factor that into the rationalization of my irrationality.

 

[MerryFrankster]

Check the pcv hose. If it has an oily residue on the inside, this means oil is coming out of the crankcase through this hose and being burned in the cylinders. Some oiliness is normal. It's excessive oiliness you want to watch out for. If you are really interested in finding out how much oil is coming out the pcv, install a catch can on the pcv line. For temporary testing, you can use a water/oil trap for an air compressor, that you can buy at any hardware store that sells air compressors, for under $20. For whatever reason the air/oil separator in the valve cover seems to lose its effectiveness on some cars. I really haven't delved into it too much, but on some I've resorted to just replacing the valve cover with one from salvage, and this did the trick of eliminating excessive oil consumption. This will not work on every car. Oil consumption is a complex issue. You can easily miss the forest for the trees.

 

[DrTom]

Has anyone used this on their MR2 before oil change?

I’m considering doing it to see if it helps with oil consumption; maybe it will free up sticking piston rings? I used it previously on my diesel excavator and it made a considerable difference. It reduced blow by gases and exhaust emissions a lot and made it easier to start.
Can you think of or know any harm it may cause?

Has anyone tried an Italian tune up? That's at least 4500 RPM for at least 5 minutes. (Italians--and Brits--do this in the highest gear, hence the name.) It will sometimes burn out the accumulated stuff in cylinders. It's fun, too... Be safe, though. Don't speed.

 

[randyinrocklin]

Has anyone used this on their MR2 before oil change?

I’m considering doing it to see if it helps with oil consumption; maybe it will free up sticking piston rings? I used it previously on my diesel excavator and it made a considerable difference. It reduced blow by gases and exhaust emissions a lot and made it easier to start.
Can you think of or know any harm it may cause?

I use it every time I change my oil. Its motor flush. I've been doing that since I was teenager.

 

[randyinrocklin]

My oil change interval is 1/2 of yours or 4,000 miles. I hear many times of people going twice that, I don't. I use either Castrol or Mobile One, 5w40 or 0w40. Hot oil pressure at idle is 12 psi and 53 psi at 3,000 rpm.

One qt every 1k is pretty bad IMHO. At 1 qt per 150 miles the whole back of the car must be grime black.

There isn't nearly as much load on an engine at idle. Every morning after the oil has had 12 hrs to drain to the pan it gets started at a high idle and rich mixture.

I'm full synthetic all the way.

 

[suoiruc]

Check the pcv hose. If it has an oily residue on the inside, this means oil is coming out of the crankcase through this hose and being burned in the cylinders. Some oiliness is normal. It's excessive oiliness you want to watch out for. If you are really interested in finding out how much oil is coming out the pcv, install a catch can on the pcv line. For temporary testing, you can use a water/oil trap for an air compressor, that you can buy at any hardware store that sells air compressors, for under $20. For whatever reason the air/oil separator in the valve cover seems to lose its effectiveness on some cars. I really haven't delved into it too much, but on some I've resorted to just replacing the valve cover with one from salvage, and this did the trick of eliminating excessive oil consumption. This will not work on every car. Oil consumption is a complex issue. You can easily miss the forest for the trees.

Thanks Frankster, that’s great!
I had considered the pcv system but couldn’t come up with anything. That’s good to know.
This is definitely the issue with my diesel tossing out oil from the crankcase vent. There is no catch can and it just pools under the engine. The motor medic helped by cutting down on the blow by gases. Before the treatment, it looked like it had a second tailpipe and now the gases are less and pretty clear; not like diesel smoke anymore.
Aloha

 

[suoiruc]

Has anyone tried an Italian tune up? That's at least 4500 RPM for at least 5 minutes. (Italians--and Brits--do this in the highest gear, hence the name.) It will sometimes burn out the accumulated stuff in cylinders. It's fun, too... Be safe, though. Don't speed.

Haven’t tried it but I’m sure the wife has.😂
I did do that with an 83 escort while running an RX treatment on my way to the emissions station for the thirteenth time and it passed.

 

[suoiruc]

I'm full synthetic all the way.

I forgot to mention that I’m using Mobil 1 full synthetic 5w-30 with mobil1 filters. Just started using the high mileage stuff.

 

[suoiruc]

Went to do the oil change today and thought I’d do the smt fluid, took the air cleaner apart and saw this. They struck again!

I wondered where the insulation went when I found the deck lid insulation chewed up.

 

[FormInFunction]

Went to do the oil change today and thought I’d do the smt fluid, took the air cleaner apart and saw this. They struck again! View attachment 89232 I wondered where the insulation went when I found the deck lid insulation chewed up.

Snakes in the intake box...that'll fix that problem right quick

 

[randyinrocklin]

Went to do the oil change today and thought I’d do the smt fluid, took the air cleaner apart and saw this. They struck again! View attachment 89232 I wondered where the insulation went when I found the deck lid insulation chewed up.

holy crap!

 

[suoiruc]

holy crap!

That was my first thought when I saw it.
Actually, it was holy banmeplease

 

[bentoddh]

Math problem, oil changes are $30 each. Driver A changes his oil every 3K miles and blows his engine at 170K miles. Driver B changes his oil at the normal 5K but his engine blows at 140K miles. Driver A spends $1700 on oil and Driver B spends $840 on oil. What does it mean?

Driver B gets to upgrade his engine before Driver A

 

[Drippy787]

Math problem, oil changes are $30 each. Driver A changes his oil every 3K miles and blows his engine at 170K miles. Driver B changes his oil at the normal 5K but his engine blows at 140K miles. Driver A spends $1700 on oil and Driver B spends $840 on oil. What does it mean?

Driver B gets to upgrade his engine before Driver A

Sounds like drivers A and B didn't bother to check their oil.

 

[suoiruc]

Hopefully, this will keep the little bastards out!

 

[suoiruc]

Here is a link talking about the color of oil.

The Color of Your Engine Oil Says A Lot; So Pay Attention | Car Buyer Labs

Did you know that your engine oil changes color? Yup, and it also tells you a lot about your engine's overall condition. Before we dive into this, it’s important to understand that while the different colors are typically indicative of different things, these shades shouldn't be considered the...

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