Dirty oil?

[DFrank]

now that my new to me '05 is back to shifting ok and no longer throwing codes, I can worry about some other stuff:

Why is my oil so dirty?

It was due for a change when I bought it, and I changed it to the Rotella T6, that I just started putting in my '03.

The '03 looks clean on the stick after 6K miles. I'd been changing at 5K, but am thinking this stuff wants to run longer? Should I do 10 and change the filter at 5K?

that's off topic.

The oil in the '05 looked dirty shortly after I changed it, and it spews soot all over the rear end and the camper.

Are these related?

When I changed the oil, it may not have been fully warmed up, like I usually do. Would a little residual make it all look dirty right off the bat?

Thanks,

Dave

 

[lpennock]

You aren't doing anything wrong. perfectly normal to have dirty oil pretty quick. Has room do with the in cylinder egregious that started with 04.5.

 

[Motorhead]

The 325hp engines have what is called "Internal EGR". It has to do with cam timing and a late injection occurrence. That contributes to the dirty oil right away.

 

[DFrank]

Well that is good to know, thanks. Should I be changing the oil more frequently than on the '03?

Sure feels like it.

So do they all make as much soot as mine does?

the area behind the tail pipe is black with soot.

 

[Regcabguy]

Try making a few high rpm runs up a hill or incline.
My cat gets sooted out occasionally as I drive for economy.
Using that procedure helps a bunch.

 

[lpennock]

Well that is good to know, thanks. Should I be changing the oil more frequently than on the '03?

Not really required to. Recommended oil changes are 7500/15K miles.

 

[cerberusiam]

Nope, I had an oil sample taken at 8k and Blackstone said it was fine to run longer. It may be blacker but the oil is made to handle it.

What turns the oil blacker is the stoich rich programming and incomplete combustion to regulate NOX. When that route is taken particulates are higher.

 

[Motorhead]

Try making a few high rpm runs up a hill or incline.
My cat gets sooted out occasionally as I drive for economy.
Using that procedure helps a bunch.

Drive it like a UPS truck! Not a BIT of carbon in their engines!