Greetings Oil Gurus, and thank you in advance for any advice on this or a link to where on this forum this question has already been answered.

I acquired an 08 F-350 with a 6.4 Powerstroke with 92k miles this summer to use as my heavy hauler, and it had a laundry list of issues at the time that I felt could be solved to make the truck useful once more as a work truck for my tree service. Its primary function is to haul heavy loads such as my 14-yard and 20-yard dump trailer. The previous owner was in a bad way, and gave me what I thought was full disclosure of the issues and priced the otherwise nice truck for 9K. Those included blown turbos and the trucks remarkable capacity to shoot fire from the muffler during regen (I had heard about that but never seen it personally until this summer). That stated, it cranked right up and my local mechanic confirmed he felt doing a DPF-R delete and replacing the turbos and for good measure the oil cooler while the cab was off and he had reasonably easy access. All of this was in my budget to rehab it. His shop is quite reputable. It's a "get in line and wait so this particular man can work on your powerstroke" type shop. I bought the truck, had it hot-shotted from Jacksonville to Orlando straight to the mechanic and did all those repairs (New Turbos, DPF-R (Stock tune - no extra ponies added), OEM Oil Cooler). He suggested the rocker arms would need replacement sometime soon (by that he meant as soon as I could afford), and I agreed I'd get to them as soon as I had the cash and could deal with a couple days down-time without the truck. In the interim he suggested I attempt to address the sludge issue with Rotella T6 5w-40, changing the oil with every 2-3k miles for the first 10k miles I owned it...and the detergents should gradually reduce the sludge.

4k miles and one oil change later, I took the truck to our farm outside of Gainesville this past weekend and the #4 rocker arm failed catastrophically at about 35 mph. The truck was immediately turned off (less than 15 seconds of total run time after failure) and I threw the transmission into neutral and wrestled her over to the shoulder using the truck's forward momentum to steer it. It was flat-bedded to Ocala where the following work was done on it by what most locals deem the best guys around for powerstrokes: These are the direct notes from the invoice.

"Verified customer concern, performed diagnosis, determined noise to be coming from internal driver side of engine, requested tear-down time for further inspection, found #4 exhaust-side rocker broken, also noticed a large amount of sludge in the engine most likely due to a lack of maintenance, recommend and replaced driver side rocker arms and bridge assembly along with injector harness and glow plug harness as well as injector supply tube. ADVISE CUSTOMER CATASTROPHIC ENGINE FAILURE MAY OCCUR DUE TO LARGE AMOUNT OF SLUDGE IN THE ENGINE."

He was less clinical in our verbal discussion which went something like, "Normally when I hand the keys to someone after fixing their truck I tell them they can drive to Texas right now and get there. I can't promise you'll make it to Sanford before the engine comes undone altogether. If you get it home you need to sell it ASAP. It might go two weeks, and it might go 2 years, but you can never trust this engine after this level of neglect. Any aggressive attempts to de-sludge the engine while its running using available products may result in a large piece of the sludge breaking free and clogging something vital which will finish it off. It's a time bomb on wheels."

He said he did his best with time and budget constraints, which included two full oil changes and dropping the pan and scraping it and completely cleaning that component of sludge. He said the only good news was a lack of any sizable metal in the pan.

I cannot in good faith sell this truck to a private owner. I don't have the cash or know how to tear it apart and manually desludge it. Nor do I really have the money right this instant to get a replacement truck. Remarkably, it is running quiet as a 6.4 ever does (top end is super quiet), and better than it has since I bought it. Computer says 14.4 mpg. No codes. No smoke. No odor. That stated, he was adamant. I'm a small company and I am responsible for this gamble which I lost out on big time, it seems. Based on this information, is there anything that can be done from a lubricant perspective short of a complete tear-down to buy me some time on a time bomb? I will listen carefully to any advice here, and answer any questions you may have to better understand the situation. I'm already pretty humbled, so play nice, please. Thanks again.

Get the rocker covers and sump removed. Use plastic scrapers and a shop-vac to clean out as much sludge as you reasonably can. If there's any baffles or windage trays that can be removed and cleaned, do so. Make sure the strainer/pick-up tube is cleaned and free of sludge. Make sure the sump and rocker covers are spotless before you re-install them.

Carry on using a HDEO with short intervals, this will gently clean the engine over a period of time. Maybe after a good number of intervals and you've got a feel for the engine and you start to trust it look to do a long interval with Valvoline Blue Restore 10w30 to give the ringlands a good clean.

I'm sure this engine will live a long life given a little TLC.

Why is the engine sludging?

The mechanic has to cover his (edit - mod). A new reman ngine is how much $$$$$ He does not want to be on the hook for that.

They make low oil pressure alarms, I would invest in one just in case

Rod

A couple of slow deep breaths here to start. Any used vehicle carries risk otherwise you buy new with warranty. I've bought vehicles that I discovered after the fact many things wrong, some major like yours. Some lasted a short time, some lasted a very long time. Take this one day at a time, and continue on your plan to gradually de-sludge it. Taking off the pan was a good first step to remove larger chunks of it, and as suggested above, under the valve covers are next. Engines are tough birds, they can take a remarkable amount of abuse. Good luck!

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You've got nothing to lose at this point, so you may as well use it. And good on you for not unloading it on someone else. IMO, if the engine is running good now, some TLC in the form of frequent oil changes and not abusing it with excessive loads will keep it running good for a long time to come. Disclaimer: I'm not a mechanic, but have always had a high mileage beater in my personal fleet, and have never had an engine fail.

continue with the desluding and drive it till it dies. if it does ,part it out or find a used engine

+2

The 6.4L is a bit of a fragile engine to begin with. I would do as he suggests to try and de-sludge it gradually. The fact that this engine has been neglected is a bad sign, because this already money pit of an engine has the potential to become even more expensive. Have you tried selling it to carmax?

Williams Diesel?

6.4L has known rocker issues. They are famous for diesel in oil from regens which in turn destroys the valvetrain. Not to mention the somewhat fragile fuel system. I also recommend unloading the truck if you can. Most shops here in town will not even attempt to fix a 6.4L like this, they immediately call for new engine because the fixes almost never seem to work long term.

Okay, so I don't want to call out the specific shop in Ocala, because it does seem they did a [censored] good job fixing the left side. I've never heard or felt it so smooth. I am also going to take it to Carmax this afternoon just to see what they say. Cosmetically it's in great shape. Always a central florida truck. No rust. F-350 Crew Cab SRW 4x4 Off Road Pkg...(I literally cannot fathom the first owner neglecting this engine like this. This was an expensive truck!) Might be able to recoup some money that way and absolve myself ethically from its future.

If they come in too low, I'll go to plan B, which is to take the advice given here on how it's life may best be preserved. Will update here after I get back from CarMax. Thanks all!

All the Ford pickup diesel engines prior to the 6.7 had minor to major issue. Go to powerstrokehelp.com and read up.

Typically people spend some major money on these engines and then they are super. Sludge may be the least of your problems.

Wasn't trying to call anyone out, was just curious because we work fairly closely with some of the guys at Williams, and they absolutely know their stuff.

Hope you get this sorted, nightmare.

That does not mean that they have a diesel engine expert. Which is what you need.

I would shop around for an indy diesel shop who has experience with the earlier PSD engines. Once they are upgraded they are great engines and do not have all the pollution stuff the 6.7 engines have.

I don't think Carmax is going to take an emissions deleted truck, and if they do, they won't offer anything because it's going straight to the auction block.

Williams Diesel, it's literally in their name and all they do is diesel. They have a good reputation