Diesel Oil Concerns

[KARNUT]

On 6/30/2021 at 6:53 AM, elcamino said:

It’s common to assume that black motor oil has worn out or become too saturated with contaminants to protect your engine and requires changing. Not necessarily. Discoloration is a natural byproduct of heat and soot particles, which are too small to wear out your engine. Since soot particles are less than one micron in size, they typically don’t cause engine wear. For comparison, a human hair is roughly 70 microns in diameter.

 

If soot particles agglomerate into larger wear-causing contaminants, the oil filter will catch them. Sometimes people who use bypass filtration systems, which can filter contaminants down to two microns, express surprise that the motor oil is still black. Soot, however, can still elude filtration down to two microns. Any finer filtration and the filter could catch dissolved additives in the motor oil.

 

Years ago when trying out the Amsoil experiment. I say that because we were skeptical of their claims. We used the by-pass from them. No oil change for 50K miles. Oil analysis was fine. Our main goal at the time was our diesel ROW equipment. You go by hours on those, obviously. Amsoil enabled as to double the hours between changes. Time is money. Our biggest savings was hydraulic. Cavitation and contaminants. Again big savings. I started a thread a few days ago about engine loss do to the wrong oil. No takers. Although daily threads about hard part failure. The dogs are at the wrong tree. That’s ok it makes people feel good to change their oil. Kinda like paint protection. 

[Ronjon]

Bump

Anyone install a bypass filter yet?

[NMTRUCKER]

I have a 2023 GMC SIERRA SLT with the LZ0 and changed the oil at 2900 miles and had an oil analysis done. The AC DELCO 0w-20 DEXOS D oil was blackish in appearance but the oil analysis showed an oil soot level of 0.1%, a fuel dilution level of 0.4%, and a Total Base Number of 5.45. All of these parameters are well within normal limits. The DEXOS D rated oils have more detergents to keep the soot suspended in the oil as well as having low ash content to protect the DPF. 

[kendall mckee]

Hi. I have the same concern with my 2019 duramax. Oil black as coal with consistency of water. The reason I'm having trouble believing this is just normal is I also have a 2001 lb7 with 330k and after 9000 mi on a oil change the oil still looks like it did when I poured it out of the jug.  ?

[Jay P]

14 minutes ago, kendall mckee said:

Hi. I have the same concern with my 2019 duramax. Oil black as coal with consistency of water. The reason I'm having trouble believing this is just normal is I also have a 2001 lb7 with 330k and after 9000 mi on a oil change the oil still looks like it did when I poured it out of the jug.  ?

Your LB7 doesn't have any emissions and no post injection. Even the newest 6.6l has post injection (injection on exhaust stroke) to help light off the DPF regen cycle. The addition of a 9th injector in the exhaust reduced the post injection but didn't get rid of it completely.

I have had all but one generation of the 6.6l Duramax and starting with the LMM the oil was black right after changing the oil.

 

Jay

Edited November 10, 2023 by Jay P

[redwngr]

LB7 (and all 6'6 dmax's) also uses a thicker oil than the 3.0

 

15W40 vs 0W20 

 

Dropping the oil when it is hot will drain more of it in a reasonable amount of time, which helps appearance. 

Either way, the 'leftover oil' is a very small percentage of the overall quantity.

 

Edited November 10, 2023 by redwngr