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Gulfcoast's avatar
Gulfcoast
Explorer
Sep 04, 2017

Dodge Ram 2500 - Diesel

Just bought a used 2004 Dodge Ram 2500 with a Cummins 5.9 Diesel engine (24-valve, I think). It has a little over 100,000 miles on it and is in excellant mechanical condition.

My question is... what type of oil do you guys use in these engines and please give any other service recommendations that you have to offer on this truck.

It has to last me a long time.

Thanks for your help.

39 Replies

  • romore wrote:
    I use 15W40, brand is unimportant as long as it meets API service classification SE or better. Oil filters, whatever the local parts emporium stocks. I did find a heavy duty air filter which is double the thickness of the standard.
    If you really want to wake it up, deep six the converter and run 4" from the turbo back as long as you are not subject to an annual inspection.


    No kitty on his 04!

    For oil filter, use either Fleetpride or OEM (which is also FP).
    NEVER, EVER use a Fram on your Cummins.
  • I use 15W40, brand is unimportant as long as it meets API service classification SE or better. Oil filters, whatever the local parts emporium stocks. I did find a heavy duty air filter which is double the thickness of the standard.
    If you really want to wake it up, deep six the converter and run 4" from the turbo back as long as you are not subject to an annual inspection.
  • ROtella or Delo, your Cummins will last too many miles to care.
  • Old-Biscuit wrote:
    I have a 2007 with 5.9L CTD
    I use Rotella Dino Oil 15W-40

    Fleetguard LF16035 fuel filter (NO FRAM junk)

    I change oil at 7500 miles and fuel filter at 15K
    Air filter...when dirty. No set mileage/depends on where/what I have been

    48RE tranny...service every 25K or sooner

    Rear diff......I change at 25K. Schedule suggests 15K but I run an extended volume cover so I go 25K

    Change out that coolant.....S/B done every 100,000 miles/60 months (Special GOLDEN coolant)
    Along with serpentine belt

    Adjust valve lash at 135K


    2004 Manual.........use Schedule 'B'


    ^^ All good recommendations.
  • Old-Biscuit wrote:
    I have a 2007 with 5.9L CTD
    I use Rotella Dino Oil 15W-40

    Fleetguard LF16035 fuel filter (NO FRAM junk)

    I change oil at 7500 miles and fuel filter at 15K
    Air filter...when dirty. No set mileage/depends on where/what I have been

    48RE tranny...service every 25K or sooner

    Rear diff......I change at 25K. Schedule suggests 15K but I run an extended volume cover so I go 25K

    Change out that coolant.....S/B done every 100,000 miles/60 months (Special GOLDEN coolant)
    Along with serpentine belt

    Adjust valve lash at 135K


    2004 Manual.........use Schedule 'B'


    I also like the new Rotella oil since they did not remove the anti-wear additives like some of the other brands.

    Excellent advice but to add the transmission needs the bands adjusted when being serviced as well.

    Those 5.9 CTD engines are about as good as they get for longevity.

    Probably will need a rear main seal soon?
  • Read this thread, plus peruse that forum. A wealth of information for you on the care and feeding of your truck. This is how I educated myself about my 2004.5 since I purchased it 3 1/2 years ago:
    Newbies Guide to your 3rd Gen Dodge Ram diesel truck

    These are good trucks, and you can make them last a very long time, but there is a lot to learn to accomplish that goal with reliability. As someone mentioned, add finer fuel filtration and a water separator to prolong the life of your injectors. The finest fuel filter you can put in the OEM canister does not filter as fine as Cummins' spec -- this was a screw up on Dodge's part. *This* is the filter setup I'm about to install.

    Also, aftermarket oiled air filters and such are not recommended. Use *this* deep filter in the stock intake housing.

    If you have the auto transmission, when it needs work, find someone knowledgeable to work on it, get a shift kit and some other tweaks and improvements to the stock trans, most especially if you are towing.

    Congratulations on your purchase and good luck!
  • I have a 2007 with 5.9L CTD
    I use Rotella Dino Oil 15W-40

    Fleetguard LF16035 fuel filter (NO FRAM junk)

    I change oil at 7500 miles and fuel filter at 15K
    Air filter...when dirty. No set mileage/depends on where/what I have been

    48RE tranny...service every 25K or sooner

    Rear diff......I change at 25K. Schedule suggests 15K but I run an extended volume cover so I go 25K

    Change out that coolant.....S/B done every 100,000 miles/60 months (Special GOLDEN coolant)
    Along with serpentine belt

    Adjust valve lash at 135K


    2004 Manual.........use Schedule 'B'
  • Gulfcoast wrote:
    Just bought a used 2004 Dodge Ram 2500 with a Cummins 5.9 Diesel engine (24-valve, I think). It has a little over 100,000 miles on it and is in excellant mechanical condition.

    My question is... what type of oil do you guys use in these engines and please give any other service recommendations that you have to offer on this truck.

    It has to last me a long time.

    Thanks for your help.

    I had a 2005 before. I ran Delo 15-40. Never any issues on oil. I had a Manual trans and every other year changed the gear oil with Amsoil. Same with the rear diff. I would also put external fuel filters on it to keep those injectors clean. Should be god to go.