My daily driver has a C12 in it with 536K on it I had new bearings rolled in at 513K and on the first oil change it started using a gallon of oil to every 1500 miles, so I changed the oil and 9000 miles in to it, it hasn't used a drop. So does anybody have any suggestions as to why this little miracle has happened? Both oil changes have been done with Rotella.

 

On another note I learned don't ever put 5" dual straights on a C12, Darn truck will make you sick to your stomach after 12-14 hours a day LITERALY!

 

Not sure I have an answer but I drive a C15 Cat that will go through a gallon pretty quickly when it's time for an oil change. After the change I can go for a month or more before adding.

 

We've had some Cummins with the opposite problem, we'd do an oil change , and in one trip it would lose a gallon, but never another drop after that. Noone has really been able to explain it.

 

5in straights on a c12 is LOUD lol i know drove a dump truck with that

 

I'm startin to get used to them, but i wouldnt do it twice!

 

I've been around a lot of different rigs over the years and I've seen that happen, too. Some of them seem to want to just run a gallon low for some reason.

 

I've seen a lot of engines that will not stay on the "full" mark. I tell my customers with engines having 8 to 11 gal. capacity to wait til the level drops to the "add" mark, then add a gallon. Many engines will loose a couple of quarts then stabilize at the level it likes to run at. If you try to keep it on the full mark, it will use oil steadily.

 

That is my experience as well.

 

agreed there. anywhere in the range is acceptable operating level. let it run where it likes to run. but obviously not if it goes below minimum.

 

Are you really getting use to them or just slowly going deaf?

 

What did you say I couldn't hear you. Well that issue is up for debate.

 

Thay want to run a gallon low because the dip stick needs to be calibrated. Common practice for CAT engines, usually done the first oil change. There are many service letters on CAT SIS web.

 

While I currently drive a Cat, I have been around a lot more Cummins and Mack engines. Some of those like to run on the low side also.

 

One of my 3406-B models will not stay full, If you leave it a gallon low it won't use any oil for app.12,000 miles. It's not unusal for these big engines to do this.