I have a stock 2006 5.9 cummins, no guages 160k miles. Auto trans. Recently I've noticed a random power loss. Along with this random power loss there's an engine knock that can only be heard in 4th overdrive while towing between 1,300-1,700 rpm range. I've been told it could be an engine knock? It's especially noticeable going uphill even on small grades. I'll give it gas and it won't speed up like it used to. Even unloaded the truck will randomly seem very sluggish, very slow spool up and poor Mpgs. Then sometimes it'll run fine but more bad then good. I change fuel filter with every oil change at 5k miles. Use diesel kleen with every fill up. No hard starts, idles fine, no white smoke unless it's at night and WOT. It'll prime fuel filter well. Truck will start after 2nd try since I completely empty canister when I change filter. Water temp seems fine after first starting truck it'll go to 200° then back down to 190° and stay there unless under load. Hopefully I guys can shed some light on this I've posted on cummins forums but got no replys. Many thanks. I'm pretty mechanically inclined so if it's lift pump or injectors I'm sure I can change that. Found great vid on you tube guy named project cummins.

 

do not change the filter that often, you need to add a 2 micron fuel filter, i think the new filter let enough dirt through to make the fca get sticky, it is on the cp3 it has a plug with two wires on it, it is held on with three torx head screws i think t25, clean the heads out with a toothpick and brake parts cleaner keep the driver aligned , they are in very tight and many people have rounded them off, clean the fca with the cleaner and shake the fca, it should easily rattle as you shake it. the 2 micron filter will also more than double the life of your injectors

 

Thanks for the reply. And I didnt know I wasn't supposed to change fuel filter too often!! I will definitely check the fca. Although someone said if the fca was dirt or bad it throw a code?? I checked oil level too and it was low maybe 2 quarts I checked it 2 weeks later and it was full as if I just did the oil change.. Idk if it's making oil. I've done the halo test on a napkin and don't see or small any diesel in the oil..

 

i dont think anyone makes a 2 micron filter.

 

Caterpillar makes them. Dieselfuelfilters.com has the whole kit. Its a 2 micron fuel filter by CAT and water separator by Baldwin.

 

Every cummins engine that's not on a dodge ram has those filters, the 7-10 micron filter was chryslers doing I believe.

 

i pretty sure that is just hear say. a few people including my self have contacted cat to get the data for the filter that everyone says is a 2 micron. no one has got a response from cat with the data saying its a 2 micron. i have also read that its actually a 4 micron filter, therefore it could be a 2 micron nominal. i like the donaldson P551313 because its a 3 micron absolute and that is the best filter out there. fleetguard FF5814 might also be a 3 micron ablsolute, but i have done research on it.

 

i have one on my truck ,Racor 460R2 Spin On Fuel Filter/Water Separator - Racor 460R2 - Racor Diesel Fuel Filters - Racor Fuel Filters / Water Separators - Fuel System - Engine/Mechanical - Boatersland Marine


by the way, i haven't had any lift pump problems since i installed the filter.....you can see the oem pumps on the frame. one is a backup pump and never been used

 

That nominal or absolute?

 

98% @ 2 microns per page 9, paragraph 2 of Filter Efficiency

Racor makes filters with various filtration
efficiencies, but its standards for non-OEM (Original
Equipment Manufacturer) are 2, 10, and 30 micron
filter elements. The actual efficiency ratings for these
are 98%, 95%, and 90% respectively.

Link below...

https://www.parker.com/literature/Ra...ron_Rating.pdf

 

i still dont see if its nomial or absolute. i have tried researching it and havent came up with an answer. but i will keep looking. i might have to email them

 

what difference does it make? it's still better than 10 micron!

 

True, but a 3, maybe even a 4 micron absolute will filter better then a 2 micron nominal.

 

The Donaldson is 99% at 3 microns, the Racor is 98% at 2 micron so I think it's kinda moot. You can have a cylindrical shaped particle that is larger than 2 microns or 3 microns on an "Absolute" rating and still have it pass through the media.

Filters are also commonly classified according to absolute or nominal ratings. An absolute filter commonly has an efficiency of 99 percent or better (> 100.0) at the specified particle size, and a nominal filter commonly has an efficiency of between 50 percent and 95 percent ( = 2.0 and = 20.0) at the specified particle size. It should be noted that these terms, absolute and nominal, have no standard definition with regard to filter performance and can vary from one manufacturer to another. Filter performance should not be evaluated based on such ratings. To truly evaluate the performance of filters, the beta ratio or capture efficiency, at a given particle size, must be obtained.

How to Define and Achieve Hydraulic Fluid Cleanliness

 

Lol if anyone has more input on the power loss I would appreciate it I've checked my fuel and filter and they're clean. So what else could it be or should I just pay the 3l$350 the dealership wants to diagnose it?