Do you burn oil? UOA show antifreeze/fuel?

[timeau]

Originally Posted By: OVERKILL
Originally Posted By: timeau
Originally Posted By: OVERKILL
The consumption should taper off. It is common to have some consumption when switching between brands.

Could you explain this phenomenon?


Likely has to do with the fresh oil stripping off some of the AW layer from the old oil and putting on its own, which results in some of the product flashing/burning off.

This is told by you, not me. So you agreed that mixing oils from different manufactures is not the best idea. Yes, I know about all standarts, on papers oils are compatible one with another, but mixing beer and wiskey in the same glass tends to severe morning headache.

Now look slightly deeper than CELICA_XX usually does. What is a flushing oil? This is a special oil with almost no additives. It's primary goal is to flush the rest of "old" additives to prevent their reaction with new additive packet. Also flushing oil has some dissolvers that cleans engine from inside. Then when new oil is added, no chemical reaction is possible, same as all particles and varnish is cleaned too. Does it make sense now?

Then you wrote:
Originally Posted By: OVERKILL
If something is already clean, attempting to make it cleaner is pointless. The only time that cleaning is beneficial is when there is something that needs to be cleaned up.

Please, take a look on the topic title. If the car already consumes 1 liter per 5000 km, is engine clean or not? Are rings OK or not? Are oils drainages OK or not? So does this engine have something to be cleaned or not?

I have one more argument. If you look on most UOA precisely, you will definitely see that almost each car consume oil. Why? Because nobody cares about proper oil changing procedure. Dry engine of my Toyota takes 7 quarts of oil, but in fact no more than 6 could be drained out. Flushing oil solves this "feature".

 

[Guitarmageddon]

If a car consumes oil, how can you be 100 percent on the source without a full tear down? In the case of a sleeved block with scored walls causing burning, what good is an engine flush doing?

 

[OVERKILL]

Originally Posted By: timeau

This is told by you, not me. So you agreed that mixing oils from different manufactures is not the best idea. Yes, I know about all standarts, on papers oils are compatible one with another, but mixing beer and wiskey in the same glass tends to severe morning headache.


I agree on this, particularly because of the extensive posting Shannow has done on the topic as of late which shows that there can be some rather significant effects on the low temperature performance by mixing oils.

Originally Posted By: timeau
Now look slightly deeper than CELICA_XX usually does. What is a flushing oil? This is a special oil with almost no additives. It's primary goal is to flush the rest of "old" additives to prevent their reaction with new additive packet. Also flushing oil has some dissolvers that cleans engine from inside. Then when new oil is added, no chemical reaction is possible, same as all particles and varnish is cleaned too. Does it make sense now?


That's not what I took away from what you wrote, which seemed to state that you do this flush EVERY TIME you change your oil. If you change your oil with the same oil, all the time, why the flush? And even then, flushing out the small percentage of old oil from a different brand likely is of little to no benefit in application. And I don't see flushes advertised for this purpose, their purpose is to clean, which ties into my next point.

Originally Posted By: timeau
Then you wrote:
Originally Posted By: OVERKILL
If something is already clean, attempting to make it cleaner is pointless. The only time that cleaning is beneficial is when there is something that needs to be cleaned up.

Please, take a look on the topic title. If the car already consumes 1 liter per 5000 km, is engine clean or not? Are rings OK or not? Are oils drainages OK or not? So does this engine have something to be cleaned or not?


You don't know either way without an inspection, you can't just base it on consumption. The BMW S62 engine, before the ring redesign, used to routinely consume 1L/1000Km or more for some examples. Yet they were perfectly clean. They consumed because of the low tension "performance" rings that were fitted to them. This was revised later on in the production run.

An engine design can have a big impact on performance and ring pack coking is not the only source of consumption. Ford had a PCV design on the Modular that would lead to the engine sucking oil through it, resulting in consumption. The fix was not an engine flush, it was a redesigned PCV hose.

Without knowing the engine's health, history or predisposition to a given trait it is nary impossible to just assume that it must be a ring or drain hole problem. It may very well just be a characteristic of the engine's design and is subsequently not a problem.


Originally Posted By: timeau
I have one more argument. If you look on most UOA precisely, you will definitely see that almost each car consume oil. Why? Because nobody cares about proper oil changing procedure. Dry engine of my Toyota takes 7 quarts of oil, but in fact no more than 6 could be drained out. Flushing oil solves this "feature".


All engines consume oil, they have to by design. The oil control rings CONTROL oil, they do not remove it completely from the cylinder walls. Same with how valve guides are lubricated, SOME OIL is always lost through them. How MUCH oil an engine consumes is the potential issue and that will vary by engine design, purpose.....etc.

There is no one template for oil consumption that all engines adhere to so it is silly to assign a single "fix" to them all based on that flawed premise.

By your metric my S62 consuming 1L/8,000Km is excessive. And your evaluation of that, in light of the design of the engine, would be completely inaccurate. That consumption, for this engine, is actually exceptionally LOW.

My Expedition would consume no discernible oil (the level on the dipstick stayed about the same) for a 10-12K OCI using M1 0w-30. It would use 3L of AMSOIL AZO in the same OCI. I ran multiple OCI's to see if this would change. It didn't. I went back to the M1 0w-30, the consumption stopped. I put in PU 5w-30, it uses about 1L in 10,000Km. I guarantee if I go back to the M1, it will go back to zero again. The engine and ring pack health aren't changing on-the-fly here. The oil drain holes aren't plugging up and then magically fixing themselves. This engine, for whatever reason, consumes that particular oil. But it is mechanically healthy. It doesn't need a flush.