what to look for when buying
 

so my dad is going to look at a used 6.4 and he asked me what to look for. i told him for sure ask about a egr delete and dpf delete. but i wasnt sure what else to look for in these motors. im assuming a lot like a 6.0 but not sure. any info i can forward on?

Ask about any prior modification, just so you know what you're working with.

You need to know how often the two fuel filters were changed, make sure they were changed no later than 15,000 miles also make sure the water was drained from the fuel at least once a month, I like to change my oil every 5,000 miles, cause of the regen(cause it will put fuel in your oil)

It wouldn't be a bad idea to have an Oasis report done to the truck if he finds one he is interested in. Also, check the radiator lines to see if they are leaking and check the coolant level. Not a huge issue but something to check out before buying.

glad i saw this as the wife wants one after i go on deployment. Eh least i get to keep my truck. How high of miles should i stay away from?

I bought my '08 with around 93,000 miles on it and only had one mishap. About a week after I bought it I realized the idler and tensioner pulley needed replaced. Other than that, the truck is still tight and rattle free. I may have gotten lucky that the PO took good care of the truck, but I wouldn't be afraid to purchase one around/over 100,000 miles.

I'd be really leery of buying a really high mileage stock 6.4... fuel dilution sucks. I'd almost prefer one that was deleted early on, or a low mileage truck (under 100k). If you find one with 250k on it, and it's bone stock.... eh....

Definitely have an oasis pulled, and if it's an early job 1 make sure all of the updates were done.

So is it really better to buy one that has had the deletes and mods then one that is bone stock. Looking at one that has 150,000 and while it looks like it has been well maintained and has the deletes it still makes me nervous.

Look for a truck that had all it's Maintenance done, oil change every (5K), fuel filters(15K), & transmission fluids(30K)

I'd be more inclined to buy a truck with 150k on it with the deletes than a truck with 150k and bone stock... fuel doesn't lube bottom end bearings too well...