Primary fuel filter

[MAScontractingllc]

Hello all My wife and I are new to the forum and own a 2015 Kenworth T680 with a ISX cm2350 and pull cans out of the Chicago rail yards and deliver to a 7 state region.

We do all our own maintenance overhead, fluid/filter changes, EGR tune up, ect (thanks to Rawze and all who help us obtain knowledge on this forum before we joined)

I would love to eventually do a "clean & safe" De-mandated with a HP increase up to what we can safely do according to the CPL (dealership says can be only be turned up to 475 with no hard parts change) some of those rail containers are HEAVY...Not looking to "roll coal" or that other ego BS It would be nice to be able to merge with that Chicago traffic and pull those Kentucky hills

we run one truck and I hate to see all of the soot in the oil (would rather do de-mandate than oil spinner).....We're so sick of spending every free minute cleaning/maintaining the egr dpf system and would like to get back to more family time.

Our previous truck was a Volvo VNL670 with d13 that we traded after 1 million miles it was never de-mandated and seemed like it was less needy of our free time(my opinion)....However I do love the T680 interior room as Im 6'5 360lbs lol....

2015 Kenworth T680
509,000 miles
Cummins 2350 450 hp
automated ultrashift 10 speed
3.36 rears
new fuel pump before we bought truck 60K ago
fluids and Filters are all up to date
treated with Biocide
no black in tanks
filters not slimy
APU (not ideled)
Oil changes at 20-25K miles With Rotella T6 synthetic
run all NN fleetguard filters
Paccar primary fuel filter unit
No CEL's
6.4MPG
EGR Tune up
New style crankcase lifelong filter


We do have Insite and Eaton Service ranger with the Grandview Engineering PC-ECM data link


I'm telling all of this so ya'll can get a better idea of who I am and what we've done to aid in your responses

I apologise for rambling on

My question is why after changing primary fuel filter the truck has good power for about 1,000-1,500 miles then seems to get real doggy and the boost goes down from 28 to a max of 25 PSI Its a real stick in the mud if you ask me

Is there something I can do to wake this baby up coming from a Volvo 13 liter 435HP to a big 15 liter 450HP I thought it would have more grunt

[tree98]

Maybe junk in the tank clogging the filter quickly?? Do you have a Davco filter on there too? If so what micron do you use? You want a 7 or a 10, if it's a lot bigger like a 50 or something you might as well have nothing at all and everything goes right through it straight to the spin on filter.

[MAScontractingllc]

Thanks for the quick response

We don't have the Davco only the factory Paccar filter
We are using 10 micron fleetguard filters in the Paccar housing
Tanks appear to be clean

I thought I read somewhere that the fuel lines could be giving up the ghost?
I don't know if they break down inside so to speak after 500K

[tree98]

Sounds like something is clogging that filter prematurely. 10 micron sounds big for a 2350. These newer engines with the high pressure rail and super precision injectors usually take a smaller micron, my X15 spin on is a 4 micron. I would look on quickserve to find out if your using the right filter. Maybe take your current filter off when the engine starts to get doggy and cut it open, see what's in there.

[JimT]

(02-18-2020 )MAScontractingllc Wrote:  Thanks for the quick response

We don't have the Davco only the factory Paccar filter
We are using 10 micron fleetguard filters in the Paccar housing
Tanks appear to be clean

I thought I read somewhere that the fuel lines could be giving up the ghost?
I don't know if they break down inside so to speak after 500K

The fuel lines could do that, though it's more of an issue with age than with mileage.

Not sure what might cause your issue, but it seems to me your oil drain interval is too long. If you're only getting 6.4 (which isn't bad for hauling containers) then I think you should be looking at 10-15k interval, especially with the egr intact. I'm sure Rawze will chime in about that.

[MAScontractingllc]

We will definitely check into those 7 micron primary filters.....That damn egr is killing this engine oil....ouch..... I was afraid I needed more frequent oil changes....De-mandate is looking better and better....don't get me wrong I love this truck and the job we do with.... would be nice to have less maintenance and DEF expenses...

[Mattman]

When you say Paccar filter I assume you are referring to the frame mounted filter not the one on the engine??

Do you have a fuel filter restriction gauge in the dash?

[MAScontractingllc]

Yes sir.... You are correct

Unfortunately we do not have a fuel restriction gauge

When I say primary filter I'm referring to the frame mounted (housing made by paccar) from the factory and secondary fuel filter is mounted to the block...I'm not sure if that's correct terminology though

Primary fuel filter (frame mount)we use a Fleetguard FS36401 (10 micron)
Secondary fuel filter (block mount) we use a Fleetguard FF5825NN (4 microns)

[Rawze]

First of all, unless you have a specific need for the synthetic, your completely wasting your money on over-priced oil. This is also why you are likely pushing 20-25k oil changes,.. and this will kill that engine and its overhead cam.

I can only say to this -- STOP ABUSING YOUR ENGINE!!!!!

NExt: if you think that de-mandating it is going to extend the oil drain intervals, then you are in some kinds of la-la dream-land too. - This will not be the case.

SO....


With your FUEL MILEAGE AT 6.x miles per gallon, you should be here...

Quote:6 - 7 MPG -- Change your oil every 12,000 - 15,000 miles or so.

AND IF YOU WANT TO EXTEND OIL CHANGES!!!--- THEN GET YOUR FUEL MILEAGE UP!!! BY INSTALLING A BOOST AND PYRO GAUGES AND DRIVE IT BETTER!

Quote:If your average fuel mileage every 10,000 miles is ...

less than 5 MG -- Change your oil every 8,000 miles or so.

5 - 6 MPG -- Change your oil every 10,000 - 12,000 miles or so.

6 - 7 MPG -- Change your oil every 12,000 - 15,000 miles or so.

7 - 8 MPG -- Change your oil every 15,000 - 18,000 miles or so.

8 - 9 MPG -- Change your oil every 18,000 - 22,000 miles or so.

above 9 MPG -- Change your oil every 22,000 - 28,000 miles or so.

AND if you want MORE PEP in those trafic lights and around town and on those heavy loads --- STOP POINTING YOUR FINGER AT THE MOST EXPENSIVE COMPONENT IN YOUR DRIVELINE (YOUR ENGINE) and START SAVING MONEY so you can re-spec the truck for what your using it for!-- THOSE 3.36 REARS ARE YOUR PROBLEM!!! <- That thing should be AT LEAST 3.90's and it will actually feel like a truck that can get out of its own way.

Turning up the engine = a LOT OF ACCELERATED WEAR in your type of operations, especially if you have any amount of stop-n-go on a daily basis. -- BUT RE-GEARING IT PROPERLY does not come with this issue.


If your going to make decisions to improve things -- then make the right ones and stop making the wrong ones!.