Diesel Tune Up?

Discussion in 'Mechanic and Repair' started by Mowman, Nov 19, 2001.

  1. Mowman

    Mowman LawnSite Senior Member
    Messages: 553

    Do diesel engines get a tune-up like gas engines? If so what is included in a diesel tune-up? Gas I know you get plugs,cap,rotor,wires,fuel filter,air filter. I have NO CLUE as to what a diesel gets if anything. Also how much does the average tune-up cost? Thanks for your help as I said I'm LOST when it comes to a diesel engine. My next truck will have one and I want to know the EXTRA COST of owning one.
    Appreciate your input.
  2. sdwally

    sdwally LawnSite Senior Member
    Messages: 386

    Diesels do not need "tune-ups". Normal servicing is all you should need. Very important that you change all filters when recommended, especially the fuel filter(s). On the newer diesels, the fuel filter will also have a water separator with it. If there are wires connected to it, there will be a light in the dash that will let you know when to drain it.
    If a diesel starts producing more black smoke than normal, then you need to change the air filter. As far as a "tune-up", at 100,000 miles or more you could have the injectors rebuilt if you are noticing a lack of performance, also valve adjustments are important on diesels.
    Cost wise, your normal oil and filter changes will cost more, however a diesel engine will last longer that a gasoline engine. In this aspect, diesel engines will cost you less in the long run.
  3. DSL DOC

    DSL DOC LawnSite Member
    Messages: 12

    in addition to wally i myself am a ASE master truck tech along with school bus and auto certs. So if anyone ever has any question esp diesel call on me...
    anyway it is the "NORM" to change the fuel filter everytime you change the oil, as well as running 15w40. I have seen very few
    problems when using dello 15w40 in diesels and stick with it if you start with it. another thing to think about with fuel filters on diesel think of how carefull we are runnin 10 micron filters for hydro drives, the injection pumps on diesel, do not like dirt.
    if you get a new truck most of them have a fuel injection system more like a car has similar to their obd II, the injectors do the pop off instead of the pump forcing the fuel through them itself, so less maintenance there valve adjustments are critical also because of the closeness the piston is to the valves at top dead center of its stroke. Have SOMEONE QUALIFIED do it. Exspensive mistake pal. they are definately superior to a gas engine in work life.
  4. DSL DOC

    DSL DOC LawnSite Member
    Messages: 12

  5. scott's turf

    scott's turf LawnSite Senior Member
    from NH
    Messages: 949

    OK, DSL DOC. Me diesel is surging when the rpm's are just around 1500. At idle and higher rpm's it runs fine. I though it could have been the fuel filter so I changed it and it is still happening. Any ideas? Thanks.
  6. DSL DOC

    DSL DOC LawnSite Member
    Messages: 12

    im sorry scotts i need to know more what engine and size and year electronic injection or mechanical usually the smaller diesel enigines run mechanincal meaning the injection pump forces the fuel through the injectors. the surge at or off idle is generally caused by the governor arm inside inj pump is out of adjustment
    what the arm is doin is swinging back and forth the weights and springs cant over come it and every time arm moves one way it fuels engine causing surge this is common ESP DETROITS you ever heard em run in morning rev down rev down rev down and should be included in a tune up by your dealer if is mechanical pump with adjustable gov i think gov is out of whack and any u gas jockeys out there leave em alone special tools to adjust if it is electronic inj prob the tps. u can to your local mechanic if he has computer manuals and have him print out a picture and test procedure for the tps. simply put
    put a needle pin in the approp wire and work throttle all way through travel and should read 0-5 volts and should respond quicly on a good multimeter also another trick on surging or drivability problems while vehicle is runnin idle tap lightly on the MAF or MAP sensor if rpm changes even slightest replace it. let me know

    DSL DOC :blob4:
  7. scott's turf

    scott's turf LawnSite Senior Member
    from NH
    Messages: 949

    It is a 7.3L international engine in my f250. I talked briefly with a mechanic I know and he said that it could possibly be the overdrive kicking in and out. I had a new trans built in the summer so maybe something was disturbed. I will call the guy who did the trany and see what he said. Thanks for your help.
  8. powerjoke

    powerjoke LawnSite Member
    from Florida
    Messages: 8

    I had the same problem, go online and look up the wicked wheel or the ats ported intake for you turbo. They're not going to give you anymore HP, but they will save your turbo and give you a little lower egt's. surge can snap the turbo's shaft if it gets too bad. 7.3's are known for bad surge and stall.
  9. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Messages: 2,613

    His trucks surging at 1500 rpms will not snap a turbo shaft, sorry. If you figure that at 1500 rpm you might be building little to no boost maybe 2-4psi then that means that in turn the Drive pressure is probably only 3 or 5 psi max...now consider that at 2800 rpms the boost is 25 psi or so and drive pressure is up around 28 or 30 the 1500rpms aint going to snap a turbo shaft.

    As for the surging at 1500 anyones guess is just as good ... could be a bad injector
  10. lucforce

    lucforce LawnSite Member
    Messages: 223

    You will need to use some additives on a regular basis or even with every fillup to keep the fuel system clean and keep the cetane level up in the fuel. Diesel fuel in the US is not as good as what is available in other countries.

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