Thommo Thompson

haha i also despise the marketing PROFESSION.
I've had to be a MARKETING person once, and when the boss wasnt happy, i just walked, i refuse to lie to ppl.
Old 83, as for the low pressure i get, yes it is low. But my point was that the extra 1 PSI actually gets rid of the extremes of the noise.
Its still there but significantly quieter. I put it down to the fact that the noise is mostly piston slap.
Oil cushioning helps piston slap a bit, and contrary to the popular internet beleive that thicker oil stops slap because it cushions it more, thats not true.
When the oil pressure drops due to oil heating and thinning, the oil exits the big end journals at such a rate that not much gets sent up the conrod to the 2 oil holes in the piston pin holes. Then it has to get pressed throught the little hole in that to make its way to the little 2 oil holes in the oil ring lands. (not to be confused with the other 2-4 oil return holes in the lands.
Now i havent seen a 22RE piston myself, but i imagine they also have the oil holes in the lands. Its these plus the oil exiting the wrist pin holes that will help cushion slap
And that is what i suspect is happening in mine.
So higher viscosity makes a difference in even worn out engines, mine is proof.
IF your clearances arer nice and tight, then you probably have no oil supply issue to begin with.
But you will not know if u shouldve been using thicker oil, until you start hearing those noises and its too late, unless u constantly monitor oil pressure.

Tilikum102602

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Thommo Thompson

My exs father had his 2002 kia rio serviced by a cheap mechanic who swore by diesel oil for everything. remember this is a late model car... when i pulled the oil cap off, i saw about 2 cm thick hardened sludge over everything in the rocker cover. We removed the cover and carefully cleaned it all out. To this day im certain its that mechanics fault for making up his own "society of automotive engineering".
I suspect that the sludge was caused by expessive blowby and moisture contamination, but its possible it was just ˟˟˟˟ cheap oil.
In the US, some TV station did a comparison of 2 engines one with rotella and one with gasoline engine oil and found that rotella (shell diesel oil) caused sludge in the engine.

Now all the people out there who say deisel engine oil is better because it has more detergents, i say to them: If it was better to have detergents, why wouldnt the oil companies engineering teams have put those detergents into the gasoline oil?

Ill tell u why, because they are paid to work out what works best and thats exactly what they did.

quoting another source..
"In a gas engine, diesel oil's greater concentration of detergent, or scrubbing agent, can remove manufacturer's deposits on the cylinder wall that help seal the combustion gases. This can lead to smoking inside the engine, which can in turn damage the catalytic converter."

Thommo Thompson

Tilikum, as u have been running diesel oil for some time and are soon to open her up, you would be a very good person to get information from regarding how clean the piston lands are when running detergent oil vs conventional oil.
Please do think of us when u tear it apart, id love to see just how clean the rings are, particularly the compression rings. i suspect that this cleanliness is the issue some face with diesel oil as it prevents quite a bit of the lubrication and sealing that sludge actually helps with around the compression rings.
For example, ever rebuild ive done (IVE DONE A LOT) has revealed a ring of black hard tar on the piston surface between both compression rings. If this tar is able to acuumulate, it means there is space for it. if there is space for it, it is better off filled.
Without it, i imagine oil contamination and blowby are both increased.

Tilikum102602

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RAD4Runner

I had always been using regular (non-high mileage synthetic) since I had my engine rebuilt 50k miles ago. I do not see any oil leaks aside from the valve cover gasket and semicircular plug (aka half-moon seal). That I will fix by replacing the seals. Therefore, I do not the claimed benefit of seal conditioning from a "high-mileage" oil. However, Wal-mart has a good price on Mobil 1 10W-40 synthetic.
Do you see any disadvantage to using "high-mileage" oil on engine where the seals seem to be working well?

BTW, I use OEM oil filter because, aside from my confidence in Toyota, I don't like spend time and money buying another size filter wrench each time I get a different filter. Helps streamline (I like minimal, you see) my tool kit, too.

Thommo Thompson

yes there is a disadvantage to using certain (most) high mileage oils if ur motor has new seals.
the seal rejuvenator, which is found in some good synthetics, and in higher concentrations in high mileage oils, will make seals swell. this is a good thing for older motors, it makes them tighter.
Mineral oils leave dirt which plugs dry old cracked seals. Synthetics have much higher cleaning properties which can remove this dirt and open up dried cracked seal leaks.
If u had a mineral oil that was leaving these handy deposits, and was also swelling the seals, then move over to a cleaning synthetic oil, u have a 2 fold compounding likelihood of springing a leak. The sudden lack of swelling causes the seal to shrink, plus the synthetic detergents clean the gunk, and bang, oil all over the place.
It would have been safer and wiser to go synthetic oil from the moment the seals were replaced leaving them naturally in there relaxed state.
i hope this makes sense.