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I recently posted this article in a new thread here. I came across something in the article that I think needs to be pointed out.
There has been much discussion here about the problems of the CP4.2 which we all are familiar with. But what I am going to point out is that maybe GM MAY have had LESS CP4.2 failures if they used a primary pump (DFCM) like Ford uses. I'm NOT looking to get into another discussion here about the CP4.2, why it should or shouldn't be used but I'm just pointing this out, that what RCD Performance says, concurs what I have read when I looked into the subject of air in the fuel of a modern day common rail diesel engine.
"Unfortunately, there is no provision in place in the CP4.2 to keep the piston from rotating within its bore. After tracing the failures it’s seen in dozens of LML Duramax applications back to either the system’s lack of an electric low-pressure fuel supply pump, improper installation of the fuel filters, or the end-user running the truck completely out of fuel, the folks at RCD Performance believe aerated fuel is the primary cause behind CP4.2 failures. With highly aerated fuel inside the piston, the piston assembly is allowed to float, which often results in the piston rotating.
The primary difference between the CP4.2 used on the 6.7L Power Stroke vs. the unit found on the LML Duramax is Ford’s utilization of an electric low-pressure pump supplying diesel to it. GM’s version does incorporate a gear pump on the back side to get positive pressure heading toward the CP4.2 (shown), but as the un-salvageable LML cores pile up at RCD Performance, it’s clear that the help provided by the mechanical pump isn’t enough.
This is believed to be the dominant reason CP4.2 failure is less common on the 6.7L Power Stroke than it is on the LML Duramax: the electric lift pump that’s part of the all-in-one diesel fuel conditioning module (primary filter, drain valve, and pump). Not just any low-pressure fuel supply pump, Ford makes sure 55 to 65 psi is being sent to the CP4.2 at all times. Any time fuel supply pressure drops below 50-psi for a sustained interval, a low fuel pressure code will be thrown.
Although it’s not as common for a pump failure to occur on the 6.7L Power Stroke, if the CP4.2 does disintegrate, you’re replacing the fuel cooler and possibly even the low-pressure fuel pump in addition to the CP4.2, lines, rails, injectors, and necessary sensors. To keep the CP4.2 in a 6.7L Power Stroke happy, maintain a strict fuel filter change regimen (performed at or before Ford’s recommended interval), make sure you change both the primary and secondary filters, ensure you install them properly, and always fill your tank with quality fuel from a safe, reputable source.
Many of us know the struggle that can sometimes be priming the Duramax’s fuel system following a fuel filter change, but this is often where a lot of the CP4.2’s troubles begin. According to RCD Performance, many owners start the engine before proper priming has been performed by hand, and then rev the engine up in an effort to push the air through the system before the engine dies. As far as the CP4.2 is concerned, this is the worst thing you can do. The best course of action is to prime the hand-pump until it’s tight, start the engine, continue priming the filter until all air is bled out, and allow the engine to idle for five minutes prior to any type of acceleration. In BMW applications that employ a CP4-based pump, it’s recommended that a program on OE scan tools be used to purge the fuel system by way of idling the engine while the VCV is cycled. The fact that this elaborate process is standard operating procedure for such a seemingly simple maintenance item leads us to believe BMW knows how damaging air can be for the CP4.
Who knew something as innocent as improperly installing a fuel filter could lead to such catastrophic fuel system failure? Due to its ability to allow air to infiltrate the high-pressure system, the guys at RCD Performance say it’s possible. Aerated fuel creates a host of issues inside fuel systems, the worst of which is lack of lubrication and inconsistent pressure. While changing out filters seems idiot-proof, if you’re doing it on your truck for the first time take a peek at the owner’s manual, just to be sure. In 6.7L Power Stroke applications, turn the key to the on position and listen for the low-pressure fuel pump. If you pay attention, you can hear the air-fuel mixture burp in the tank after two or three cycles. Then let the truck idle for five minutes to ensure all air is gone before accelerating."
I still have an Air Dog to install on my truck, but my S&S DPK kit will be going on soon. My truck is paid off this coming February and will continue driving it past 100k miles, now at 96k miles. I hope to keep her running for many more years.
This is some good information. I just let my dealer do this because I have no place to get rid of the fuel when I change the filters. No way would I ever just dump in back into the tank.
I still have my old fuel in old plastic containers that I will burn when I have a Fire out near my shed. Probably cleaner than a Smokey deleted truck just spewing unspent diesel fuel out the tailpipe...
"From a sump capacity perspective let's just say that there is such a thing as overkill. When you look at the industry as a whole from a "cost of ownership" perspective, which btw is one of my job functions, Ford was out of bed. The migration from a 3K mile oil change to 5K to 7.5K and now finally 10K has been a very frustrating experience. Not so much that the capability wasn't there, it's that engineers are, well, way over-protective at times. When you look at the cost impact to the customer associated with improving overall maintenance requirements, it's a pretty big deal. At one point we were at twice the cost of our primary competitor for 5yr 100K maintenance for oil, oil filter, fuel filters(s) and air filters. If you’re a fleet owner, some of which have many hundreds of these trucks on the road, you have to be sensitive to this. If you want to see how crazy this is getting, checkout what's happening in Europe from a cost of ownership perspective. OEM's are competing at selling a vehicle based on the maintenance interval of 1 (Once) every two years! or 30K Km. (insane)"
Here's a question from that sticky:
"It's great to understand the reasoning for Ford sticking with exhaust-stroke injection for dpf cleaning. It seems that the only negative is the potential for oil dilution due to fuel contamination.
Is there any data on what type of driving creates the best and worst case scenario for oil growth? Heavy towing vs. grocery-getting use? Also, is there a maximum acceptable fuel content threshold in an oil analysis? In other words, should the oil be changed if the fuel content is greater than 5% or 10%? What is the maximum safe level where the oil is still able to do its job?"
Answer:
"It's become negligible for the most part. 7% fuel in oil is the number that used fairly consistently as to when to start to get nervous. Worst case duty cycle is max gvw, low speed operation, urban city driving. Keep in mind that you'd need to run above that percentage for extended periods of time to have any significant affect and the intelligent oil minder system would make you aware that an oil change is required long before that. Early on during engine development, we had targeted a 15K oil change interval. Test data showed we could get there for all but the most severe conditions and even that was borderline to being acceptable.
"1st post, long time lurker, recently joined as an FTE member. I work for Ford btw and my name is Paul.
The 6.7L is more efficient from a base engine design perspective. Migrating to the CGI block material from grey iron results in much less cylinder bore distortion as well. DPF regeneration impact on oil has also been reduced significantly by using fewer "active" DPF regen cycles (post injection) in favor of "passive" regen.
The end result is far less fuel in oil dilution under most operating conditions. Extended idle and low speed stationary power applications can accelerate fuel in oil percentages over time to some extent. Truck operation at moderate highway speeds will keep this in check.
The oil life monitor/systems programming is designed such that it monitors the engines operating parameters (temp, speed, engine load, frequency of dpf regen events, etc.) and adjust oil change intervals accordingly. Some of our fleet development vehicles such as FP&L have reported >9K miles before the oil monitor activated. Note that these fleet test vehicles, along with the others we have across the country have an oil analysis performed after every oil change in most cases.
During engine development it was determined that DSI (down stream injection or 9th injector) was less desireable for a number of factors for this engine program. Refinement of the active/passive regeneration strategy, eliminating the complexity of having another low pressure fuel system to manage, improved engine efficiency and the cost were just a few of the variables.
My intent is to post from time to time when the opportunity presents itself and learn what I can to help make our products better in the future. Please know that I only frequent FTE once a week or so when workload permits and athough unfortuneately I'm unable to respond to every question or concern on the forum regarding the 6.7L or Super Duty, I will try to provide relevant information when/where I can (such as above) within the guidelines of the company. Typically I've found that hearing direct feedback from multiple owners on a particular topic/thread provides a good overview of what the good the bad and the ugly is.
Thanks for your time, have a great day!
-Paul
Disclaimer: I work at Ford, and this is my own opinion and is not the opinion of Ford Motor Company."
My point to post this is; old habits die hard and YMMV. I just wanted to post up that if you had to go past 5k miles, it's not going to kill your 6.7 engine. I let my OLM tell me when to change the oil. More recently I have had Blackstone UOAs done but I did not early in my truck's life. Anyways...
Which oil, what grade and when to change are very personal subjects which will vary from owner to owner. I see a lot of new people here so I decided to post this up to let all of us know of the effort of Ford to test these 6.7 diesels when it came to durability and maintenance schedules. Anyways, welcome to the new people and hope others find this interesting and useful as well.
And thanks to @pbruckne for posting this inside perspective on the engines in the trucks we love.
Lots of good info here, keep up the good work, I will share a recent experience. Changed fuel filters and used Wix as I had a found a reasonable priced package deal with an oil filter included. Will never use again as the fuel filter leaked and it was a manufacturer defect. Could have burned my vehicle to the ground pretty easily, needless to say I will continue just using factory filters as I’ve never had this problem before with Motorcraft
Lots of good info here, keep up the good work, I will share a recent experience. Changed fuel filters and used Wix as I had a found a reasonable priced package deal with an oil filter included. Will never use again as the fuel filter leaked and it was a manufacturer defect. Could have burned my vehicle to the ground pretty easily, needless to say I will continue just using factory filters as I’ve never had this problem before with Motorcraft
Will do my friend... Good to hear from you as it has been awhile. Hope things are well...
So i filled my DEF tank yesterday, 2325 miles out since the last fill up. I used about 2.5 gal, give or take. I use the Motorcraft fill up nozzle.
Just thought I'd mention this since there has always been talk about this subject often. I have let it run down to the 500 mile limit a few times but most of the time, fill it every 3k to 4k miles. I once read on here to do that from a Ford factory tech. I've never had the problems that some here seem to have by doing this which seems to confuse the sensors in the DEF tank for fluid level.
I also emptied my oil catch can. In the summer time warm weather here, I can let it go for the whole time because it looks like used oil and there is not a lot of it.
But once it starts getting colder, the can starts collecting the condensation that the oil burns off once the oil gets up to running temps.
Here's a few pics of the drain. It was about 65 ml of water and 15 to 20 ml, guesstimate, of goop. The last entry I have for a drain is in February at 86394. It was drained at 96200 miles. No way I had no drains prior to the spring after the one in February. Oh well...
What happens is the oil absorbs some water and it looks like a goopish mix of schitt essentially.
Prior to me draining out the water.
The goop in the bottom prior to me dumping it out into the old gallon bottle i have for this schitt.
Scooped most of it out prior to wiping out the can with a paper towel.
The drain collection bottle of this wonderful schitt I'm keeping out of my engine.
Nice truck but it's not worth ~$24k dollars with that many miles. Would also like to see the service records and if any mods were performed on the truck.
Nice truck but it's not worth ~$24k dollars with that many miles. Would also like to see the service records and if any mods were performed on the truck.
I saw this on my news feed. I am not sure why there is a shortage because diesel is less refined than gas. The east coast is worse than the west.
Diesel here is $5.99 to $7.15.
