300,000 miles on 04 5.7 hemi. What to expect here on out, until it dies?

Discussion in 'Non-Ford Engines' started by scooper77515, Sep 14, 2015.

  1. scooper77515

    scooper77515 No current projects.

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    I have maintained this vehicle very well. At this point, I have just turned over 298,000 and don't expect much more out of it. I have a plan for replacing it with a crate 5.7 hemi with 3yr/30,000 mile warranty.

    When will I know that it is time to take it in for a swap, and what should I expect from the current engine between now and then?

    The only symptoms I have suggesting that this one is wearing down is a little oil blowing past the PCV and leaving a little oil on my air cleaner box, and it is "burning" or losing 1/2 to 1 qt of oil every 1000 miles or so. Not consistent burn/loss rate, and not leaking under the car.

    Any experience out there in wearing out an old engine? What can I expect here on out?
     
  2. Krazy Comet

    Krazy Comet Tom Supporting Member

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    Check the PCV system thoroughly, if it's partially clogged often oil will blow into air cleaner and engine consume oil as well... Of course if engine has developed heavy blowby not much can be done, keep oil in it and maybe switch to HD 15W-40 oil to lesson oil usage... Those oils generally stand up better to heat from blowby on ring pack and cylinder walls... If consumption is mostly from worn valve stem seals, it's probably got another 100K miles or more left in it...

    As long as it's not using over a qt per 700-800 miles, I'd run it till it drops...

    BTW what scares me most is replacing engine and then a high mileage transmission taking a dump...
     
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  3. scooper77515

    scooper77515 No current projects.

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    Yes, transmission would be last thing to go (and/or A/C, but that is relatively minor).

    Rear-end has already blown out, and been replaced with Detroit Tru-trac, so I am good there.

    Body, interior, everything else looks like only a 4 year old truck.

    Now, when you say "til it drops"...what does "drop" mean? Are you just referring to the amount of oil?

    Another 100k would be NICE!!! Another 3 or 4 years! I would LOVE to be able to say I nursed an engine to 400,000 miles.

    So far, other than this one, the most I ever got was 285,000 on an old 280 zx before I sold it, but it got sold because the body rusted away from me. Engine and drivetrain were still spot on.
     
  4. scooper77515

    scooper77515 No current projects.

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    Also, what is "HD 15w-40"? Are you talking diesel engine oil?
     
  5. Krazy Comet

    Krazy Comet Tom Supporting Member

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    Yeah I mean run engine till it has a obvious major issue, swilling oil, low oil pressure, knock, tosses a rod, timing chain etc...

    Yes 15W-40 is diesel oil but is also certified for gas engines, I have Rotella 10W-30 in my new Comet 306 & almost 200K mi '96 F-150 as well(plus it cheap on sale, which is almost continually)... I used to run the 15W-40 when I had my '93 Lightning... If you haven't tried them you could go to a 10W-40 high mileage oil, Valvoline Max Life, Quaker State Defy etc are good as are similar oils... Basically these oils recondition seals, may help if valve stem seals are the issue... Usually require 4-5K miles before there is a noticeable effect...

    Again chainging oil weights assumes the the PCV system isn't at least part of the issue...
     
  6. scooper77515

    scooper77515 No current projects.

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    I have blown the PCV valve clean recently. Might try to replace it, and see if the brake cleaner isn't doing the trick. Cheap fix.

    And there isn't a "lot" of oil there, just a 1/4" ring around where the hose goes into the air cleaner housing. Not like it is dripping down the housing or dousing the filter with oil.

    I am due an oil change in about 2000 miles and will try a couple rounds of the higher viscocity HD oil. Can't hurt a thing!

    When I first started noticing 1/4 qt burning each 1000 miles, I started using Lucas hi mileage additive, and I have been using the Castrol hi mileage 10w-30 since around 100,000 miles.

    I see that Rotella on sale a lot around here. I even used it as a break-in oil for my maverick when I built the new engine. I think. If I recall, it had high zinc content, which was recommended for break-in.
     

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