Having bought on 08 6.4 used with 98k miles on it. First thing was to change the oil and filters as not sure how well the prior owner ( company lease) took care of it. I been reading these 6.4 engines run dirty but there is a way for me at least so it does not have to be that way.

Ran engine hot and when I first removed drain plug, noticed 3/4" of sludge on top the plug. I filled it with "newish" oil drove it 10 miles, the oil still drained dark as black paint, light from a flashlight could not penetrate the darkness. so at 98K miles (october 12) just two oil changes with a new filter. I was never happy and was left with the impression sludge still sitting in the oil system.

Last weekend I gathered plenty of "newish" oil ( I work on diesel generators and customers contracted for annual oil changes on emergency generators that never ran more than an hour in a year still get an oil change, if it drains clear I save it for my truck). So now at 102K miles I ran four more changes, the fourth one draining it ran clear, installed a new filter and put in a fifth with new oil. ( 16 gallons "newish' oil and 4 new one set of filters)

Well I know now I have no sludge and second the next day I would notice my engine temp did not ramp up to a normal operating temp as fast (twice as long).

Conclusion: Perhaps it cleared out a couple of components preventing a part or two from being replaced down the line.

Seven oil changes in 4k miles. Spoiled truck.

 

Just make sure that the oil you're using in your 6.4 engine is made for an ULTRA LOW SULFUR DIESEL engine (LOW ASH)

 

I don't even think you can find derated oil anymore everything I have been using for the past 3 years is at least API spec CJ-4.

You sure your not talking about the fuel as it's getting near impossible to find diesel without it being the ultra low sulfur diesel, that includes off road diesel and heating oil products.

 

I also just bought a 2008 6.4 and will be doing oil change and fuel filters

 

I see you went from the 7.3 right to the 6.4 .. Humm skipped right past that 6.0 can't say I don't blame you one bit. I got quite the scare when I first removed the oil drain plug and found plenty of sludge on it. Yeah diesels run dirtier than gas engines but servicing diesel generators I never seen it that bad.

I am going to Brazil on vacation and I want to test drive the F-250 down there as the Fords made in Brazil can come with the Cummins engine.. I got to get that on video.

 

Yes sir ive had 93 cummins, 94 cummins, 97 cummins, 02 cummins,94.5 powerstroke, 97 powerstroke, early 99 powerstroke and now an 08. Just ordered EGR Delete, Coolant Filter, S&B dry filter, and 4" Straight and picking up a Spartan Monday for great price and then need get oil/oil fiter and fuel filters. Hopefully be a good truck