Posts
271
Joined
1/7/2025
Location
Texas, TX, USA
Fantasy
Has anyone here had the dreaded CP4 grenade on them? Even further.. were you able to have it covered under your insurance? An acquaintance of mine had it covered under his insurance policy. I have a claim submitted but I'm still waiting on an answer. I assume they are going to take my fuel filter, and probably fuel samples.
Mine crapped out at 73,000 miles. I never checked with insurance but dealer quote was $19,000.
That's rough. You can buy a (nice) crate engine for that much. I'll be doing everything myself, but it's still nearly $6,000 in parts.
My sons did on the way back from Havasu towing his boat. Only had 86k on her, had to call me to come get him. I’ve got a 2002 7.3 with 511,000 miles on it. He always would say” you think your truck will make it “ after passing his 6.7 on a flatbed headed towards Palm Springs. I picked him, his family and boat up. All I could do was smile and he now knows whose truck will last. It cost him 15k and he tried his insurance but NO go!
The Shop
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Luxon 4-Post Bar Mounts
$189.95 - $239.95
These threads tend to pop up now and then and every time I thank God i do not need a diesel truck.
I saw one thread a couple years back and a guy had some failure in his half ton Ram...twice. A smaller diesel engine? $12,000 each time
Reminds me, I gotta swap mine before she grenades 😳
Do it ASAP, man. It was the next thing on my list after a delete and a lift pump, but I kept putting it off because it's a big chore. These things are too fragile. I run Cat fuel filters and a lift pump, which was supposed to help relieve some pressure off of the CP4 as well as about double the filtration. I regret not swapping it out doing it the day I brought it home. 130,000 miles and absolutely babied in every way lol.
You can get CP4 disaster kits for cheap. Not sure how well they actually work, but they do exist, might be good insurance? The ones on Amazon look the same as the ones the diesel stores hawk.
Serious question - I see these trucks running around with these huge dual screw on fuel filter kits hanging below the bed sides - I'm assuming this is a "FASS" fuel kit that I hear referenced so often. Do these overkill fuel filter kits filter out the anti wear additives added to diesel fuel to help these mechanical high pressure fuel pumps?
Yes, the filters you see hanging are likely either a "FASS" or "Airdog" lift pump. They're almost identical and I believe the companies may be related in some way. The purpose is to push fuel up to the high pressure fuel pump, and also allow much better filtration. I'm far from a filter expert, however from what I understand it would not remove the lubricity from the fuel. FASS claims that fuel actually has more lubricity due to the pump circulating more fuel through the filters than is used by the engine. I have no clue how true this actually is. The factory duramax filter is good for particles up to 4 Microns, the Caterpillar filters that I run are 2 Micron filters.
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Here's a couple of pictures of what mine looks like, I pushed mine up about as high as it would go. The picture you posted looks like filtration only, or a different setup that I'm unfamiliar with.
From what I understand the Powerstroke disaster kit works well but isn't compatible with Cummins or Duramax. Exergy offers a modified fuel pressure regulator with a double mesh screen, but it's had very limited success in the real world. I was told that I was better off putting that money towards a CP3 on my Duramax. Hindsight, I wish I'd have just tried it.
If you have a duramax from 2011 to 2016 you can get a CP3 conversion kit so you don't have to worry about the crappy CP4. I swapped mine out for a CP3, took me about 12 hours and cost something like $2K? Expensive insurance. Also put on a lift pump. Blows my mind Ford is still using this pump. Chevy stopped in 2017 and Dodge only had it in the Cummins for 2 years (after Chevy had all of their problems). No idea why Dodge, after seeing how much it cost Chevy, decided to put it in their trucks for a couple of years (2019 and 2020). Almost all of the major problems on newer diesel trucks can be traced to absurd emissions regulations (including CP4).
Going to be checking out a 2018 F550 with 150,000kms on it in the next day or two. Pending that I am leaning very heavily to getting it. But this CP4 talk is giving me the willies. Are they really that vulnerable if you keep on top of filter changes?
Short answer: yes.
Long answer: yes also, but....
Every Ford Powerstroke from 2011-Current, every Duramax from 2011-2016, and several years of Cummins use the CP4 fuel pump from the factory. So the sample size is huge, but it seems like a really high number of them have had major problems. I'm meticulous about maintenance, I have a lift pump with CAT filters with double the advertised filtering rate, and I pretty much only buy fuel at big busy stations and I was still bitten. If you buy a truck with a CP4 just put aside a few grand for a conversion as soon as you roll out of the lot. It's too unpredictable and sensitive to try and run with it in my opinion, especially when the repair runs well into 5 digits.
For the record, that truck should be a great truck, aside from the fuel pump.
The Fords seem to fare better than the 2011 to 2016 Chevys because they come stock with a lift pump, where the Chevys do not. Some guys think fuel conditioners help, drain the water separator frequently and never let the fuel run out. The CP4s only lubrication if the fuel...
Been reading up on additives also. Really mixed info there. Some swear by them and certain brands, some say they don't help and maybe even make things worse.
Dang.
Been watching quite a while for a replacement for our 2000 7.3. It's getting a little long in the tooth in places. Can't quite justify new yet. Which would likely be the gasser.
So back when I used to work at the dealer and delt pretty regularly with some of the GM engineers I asked one of them about the CP4 pump. He told me that the 2500/3500 duramax trucks had failures and when engineering was looking into the how/why they noticed there was not a single failure of a CP4 pump in the medium duty trucks. The only difference between the light duty and medium trucks is the medium duty trucks come with a lift pump in the trucks. Big part of the reason the 2020+ duramax trucks come with a lift pump even though they went away from the CP4 in the L5P.
Pit Row
I'd have to read into that study, but my sample size of one disagrees with lift pumps or extra filters helping. I have a FASS 110 with 2 micron Caterpillar filters. Like I said, sample size of one, but a lift pump didn't do me any favors.
Had a quick in person this morning. About 80% sure I'm getting it. Subject to test drive and maybe a mechanic check. Hope to arrange that this week.
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