Ford 7.3L Diesel questions

Discussion in 'Trucks and Trailers' started by genesis215, May 5, 2008.

  1. genesis215

    genesis215 LawnSite Senior Member
    Messages: 795

    I have several questions about the Ford 7.3L diesel engines. Is the Powerstroke more reliable than the IDI? Are repairs more costly on the Powerstroke, and less expensive on the IDI? Which engine lasts longer? Which one gets the best fuel mileage? What is your experience with the fuel mileage of these two engines? Does a turbo increase fuel mileage, or decrease it? Have any of you gotten over 20 mpg with either engine?
  2. JRS Landscaping

    JRS Landscaping LawnSite Senior Member
    Messages: 817

    go with the powerstoke it is less maintaince and more powerful and reliable. i havent seen more than 15mpg in my powerstroke and its 2wd
  3. TXNSLighting

    TXNSLighting LawnSite Fanatic
    from DFW, TX
    Messages: 6,464

    powerstrokes alot better, but the idi's are easier to work on. alot simpler engines.
  4. jkilov

    jkilov LawnSite Bronze Member
    from MS
    Messages: 1,415

    I'm sorry for the long post but just can't help myself.
    Used to be one BIG diesel fan, not any more, oh no, no sir.

    If you buy a modern diesel these days you are guaranteed to be riped-off, abused and force-fed with big repair bills for components that just don't last. It's not a problem of diesel concept, but rather of the car industry's hunger for your cash and the high-tech components are a great excuse for presenting big bills. So what are these components:

    #1 : Dual-mass flywheel <- Never buy a truck with this thing. It's designed to reduce engine torque pulses and therefore protect the transmission, so the excuse. Some powerstrokes have it and it's supplied by Luk. Once you start reading Luk's docum. on the DMF you find out it reduces pulses by max 9% (well thank you) and can even amplify these under certain conditions. The real problem with the DMF is that it "wears" all the time. As it eventually starts breaking apart, gets out of center, wobbles and destroys your clutch. You will be left with a lovely $800+ bill for the flywheel alone + clutch + plate + release bearing + labor = $1250 fast. This can occur as soon as 50k miles. A DMF failure is 100% guaranteed sooner or later. If you own a truck with a DMF, some can be replaced with a solid flywheel + special clutch kit and your troubles are over.

    #2 : Turbocharger : Treat with respect. Don't rev when cold and NEVER do a "heat soak", always allow the turbo to cool down for 2min after heavy loads. Do this or miss an oil change and the turbo will stick, leaving you with a lovely ....... Some turbos can be overhauled, which can save you a buck.

    #3 fuel pump, injectors and fuel pipes: On modern diesels the fuel pump works at very high pressure. One tank of really bad fuel and the pump or injectors can fail. Fuel pipes can start to leak without reason. You will be (unpleasantly) surprised with repair costs for such small components.

    So basically, you spent more money on a modern diesel expecting savings in return. Mmmmmmm ......... yeah right. There are other disadvantages as well :
    - harder to repair
    - hard starting, specially in cold weather, will sound like the whole world is going under.
    - less power and not rev happy.
    - longer warm up time
    - truck is even more nose heavy.
    - more noise (except modern diesels)
    - lame acceleration (except modern diesels)
    - NOx exhaust emission are known to cause cancer and blood/heart related diseases
    - Soot emissions or partical matter as they are caled are known to cause asthma and other respiratory disjunctions. I'm not saying gasoline exhaust is good for your health, but it's not anywhere near the healt hazard diesel exhaust is.
    - anemic engine brake, expect faster brake wear.
    - you are paying the same price or more for a gallon of unrefined, untreated fuel, that used to cost 1/2 the price of gasoline. The oil companies simply love you.

    OK, let's not forget to mention the good stuff about diesels, after all they put them on locomotives, tractors, bulldozers and stuff :

    - more torque at certain revs.
    - more mpg's, but it's not a straightforward comparison as diesel fuel has higher density.
    - last longer
    - harder to overheat
    - use much less fuel at idle and low loads.
    - sometimes longer exhaust life

    Now I'm no self-proclaimed diesel expert. What I wrote here was gained from experience (and frustration) by owning modern diesels. I wish I knew all this before.... I lost a pile of ca$h and not to mention a lot of nerves. DON'T LEARN THIS THE HARD WAY LIKE I DID.

    Stay away from modern diesels. Buy cheap and you'll be happy. It's just my experience and a non-professional opinion. I'm not saying everyone will have all the problems I did, so please don't shower this post and turn it into a bashing arena. I'm not bashing diesel, ford or any one else and it's a quiet day!
  5. tnmtn

    tnmtn LawnSite Bronze Member
    from NE Tn.
    Messages: 1,022

    i can't say much about the powerstrokes but do have an idi 7.3. mine has 250,000 miles and runs fine. i use it for hydroseeding and towing lighter loads. i have been very impressed with this truck. i get 17 mpg when light, in town or on the road doesn't matter. i could probably do a little better if i tried. mine has the 5 speed manual. i think this is important if you go the idi route. they are not powerhouses but do work very hard without complaint. repairs are not expensive at all. i wouldn't hesitate to go with an idi again. in my opinion whether to go idi or powerstoke would have to be based on the weight of the loads you haul and how hilly it is where you live and work.
    good luck,
  6. stroker51

    stroker51 LawnSite Senior Member
    Messages: 819

    I've got an IDI and two powerstrokes. My 96 'stroke has 210K and I run it everyday, that truck is really my business. Pulls the mowers all summer, carries the 200 gallon sprayer, pushes snow and hauls the salt hopper all winter. I personally will never own another IDI, simply because, at least the one I have, won't touch my 'strokes for power, and I have done more repairs to the IDI in one year of ownership than I have in over 3 years on my 96. I have gotten, on 3 separate tanks, 22 mpg with my 96, extended cab 4x4 5 speed, my buddy had an identical IDI with Banks sidewinder turbo kit and it wouldn't do any better than 15 mpg. I usually average 13 pulling my 18' flatbed loaded with mowers. There are a lot of people who swear by the IDI's, I'm just not one of them, nor do I personally know any of them. For $350 you can put an edge evolution on a 7.3 and have a truck that will pull way more than it reasonably should. The other thing with an IDI, the absolute newest one you will find will be an early 94 model, and unless it's been sitting in a garage it's whole life will be showing it's age more than likely for a truck that old. They're both good choices, but like I said I prefer the powerstrokes hands down.
  7. TXNSLighting

    TXNSLighting LawnSite Fanatic
    from DFW, TX
    Messages: 6,464

    new or "modern" diesel are fine. not sure what that guys talkin about.. i couldnt read it all (a.d.d)
  8. mag360

    mag360 LawnSite Silver Member
    Messages: 2,445

    A realistic comparison between the two would be that of a carbed gasser versus a fuel injected gasser. Carb is cheaper to buy and keep running (or replace) but fuel injected will squeeze out a couple mpg's and have more useable power.

    I'd take the IDI for a mowing rig and the powerstroke for hauling a skid, tractor, dump trailer, etc.

    Good luck.
  9. thecollector

    thecollector LawnSite Member
    Messages: 19

    Drive both and it will be easy to decide which one you want. It all comes down to how much you have to spend. Try for more info.
  10. mybowtie

    mybowtie LawnSite Senior Member
    from NY
    Messages: 683

    Wow...first he says diesels have less power, then he says they have more torque. Which is it??? With 50K on the od, everything should have been covered under warty.

    As far as the 7.3, it the best motor ford had. Look for a manual tranny, might be hard to find one. If your gonna tow heavy loads, get the diesel.

    Ive got a 07 dmax, and get 14-16 towing 4000 lbs around town. Friends has same truck, but a gasser, and gets 11-12 towing same weight. I get 420 miles+ per tank(30 gal). With the 6.0 gasser it would cost me $10 less to go the same miles. Small price to pay for more power/torque..:usflag:

    7.3 is the best diesel ford had.

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