Edmunds Answers



  • 0patience 04/30/11 4:03 pm PST

    Is the check engine light coming on? If so, what were the trouble code numbers?
    If not, then I would start by checking the intake system.

    Air filter, intake tubes for leaks, turbo leaks, etc.
    These engines have been known for the Exhaust back pressure sensor to be a problem.
    Use the Answer this Question button to reply.

  • kathy63 05/01/11 1:38 am PST

    No codes came up, is that a cam sesor you were talking about? I just changed that about a month ago.

  • 0patience 05/01/11 3:39 am PST

    The EBP sensor (exhaust backpressure sensor) isn't the same as the crank or cam sensor.

    Does the engine have an air sound to it when you give it throttle? Kind of like it sounds like it is hissing air out of the turbo? If so, then the EBP sensor or backpressure valve may be the problem.
    Most Ford dealers mechanics who deal with the diesels should know of the problem and should be able to diagnose it pretty readily.

  • kathy63 05/01/11 12:34 pm PST

    One more question, sombody told me it could be the fuel cap? They said you should not be able to blow through it? I can blow through mine. Would this cause it to lose power? It runs great for a little while then it will just start to slow down and have no power and run ruff. When I say no power it will not go above 5 or 10 miles an hour. I really appreciate all your help. I don't have a lot of money so any help is great.

  • 0patience 05/01/11 3:17 pm PST

    No, the fuel cap would not cause those symptoms.
    The fuel cap would not cause a power loss and would trigger the check engine light on gasoline vehicles. Diesels have a bit different system, but regardless of the system, it wouldn't cause a power loss.

    People who suggest the fuel cap use it as a catch all answer, cause they either don't know or don't understand the systems.
    Now, back to the problem.
    Need answers to all of the questions. Be as specific as you can.
    How is the fuel pressure? Is it running in the normal range?
    Low engine oil pressure can cause problems with the high pressure pump (injection pump) and not supply the proper fuel pressure.
    When you step on the throttle, what does it do?
    Does it just seem like it isn't getting throttle?
    Does it cough and sputter? Does it seem like it wants to rev up, but like the transmission is in gear with the brake applied?
    Have you pulled the air filter and ran the engine to see if it makes any difference in the running of the engine? It is possible that a pluged air filter would cause those symptoms.
    Is there an air leak noise when it is given throttle?
    When it has the power loss problem, push on the shrader valve (the tire valve) on the fuel filter housing and see if fuel comes out or air.
    If air comes out, then air is entering the fuel system and causing the problem.
    Again, please answer the questions and be specific. The more information you can provide, the more we can help.
    Use the Answer this Question button to reply.

  • kathy63 05/01/11 5:03 pm PST

    First I want to thank you for taking the time to answer my questions. I will try and answer your questions as best as I can. The truck has normal oil pressure, I am not sure where to check for the fuel pressure? The truck has plenty of power when it's idleing. It's when I am driving that it loses power. When I press hard on the throttle it will take off for a little bit, then start to lose power and cut in and out, it also makes a knocking noise. The engine does not try and rev up. I can't really hear any air leak noises. I also don't see anywhere on the fuel filter that looks like a tire valve, it has a solid cap on top. I took off the airfilter and drove it around the block it drove a lot better cut out just a little this time, but still does not have the power it usually has. When I use to get on the throttle it would blow black smoke, but now it doesn't blow out any smoke. I thought that it being a diesel truck it is suppose to blow out some black smoke? I thought maybe it's a bad batch of diesel? Just guessing now, I really hope I don't have to take it to the Ford dealer, that will cost a fortune. Thank you again.

  • 0patience 05/01/11 6:14 pm PST

    Ok, we're making some progress here. Sometimes you have to eliminate what isn't the problem, before you can figure out what is the problem.

    On the filter valve, my mind was on the older filters. Your year only has the water drain valve, so that isn't much help. Sorry about that.
    Unfortunately, you are at the point where you need to hook up a scanner and pull codes. Here is a cheap code reader that would at least pull the codes and clear them. And just because the Check engine light isn't on, doesn't mean that there isn't any active codes. Just that the active codes didn't trigger the light.
    With the codes, it may give us an indication as to what is causing the problem, but I am really leaning towards a problem with the Exhaust Backpressure sensor or valve.
    But, if you could get it to an AutoZone or check around at your local auto parts stores and see if they pull the codes for free. If we had the codes, that would help greatly.
    The backpressure sensor is located just a bit behind the belt tensioner. It will be attached to a small pipe with a bracket holding it on. Check the pipe that it is attached to and see if it is cracked or loose.

  • kathy63 05/01/11 7:37 pm PST

    I had someone use one of those code readers and there were no codes that came up. That's what confuses me, I would of thought if there was a major problem that at least a code would come up. That would make things a lot easier. I looked for the hose that you were talking about, but there is not one unless I am looking in the wrong place?? Should there be black smoke when I hit the throttle, because there is none at all.

  • 0patience 05/01/11 8:18 pm PST

    Here is an image of the sensor and tube (it's a pipe).
    It is just below the idler pulley and kind of behind the tensioner.

    Since there are no codes, we have to start assuming it is a mechanical or fuel problem. Have you drained the water from the filter? There is a red or yellow handle (may be black with letters that say drain) by the fuel filter, you turn it to drain some of the water or fuel out of the filter. It may drain onto the ground, so be aware of that.
    As for the black smoke, it may or may not under full throttle, so we can't really go by that.
    I'm surprised that there are no codes, as the engine running faulty should have triggered a few codes that are unrelated to the problem, but caused by the problem.
    I'd replace the air filter, since it made some difference by pulling it. Check ALL of the intake piping and make sure there are no cracks or loose connections. In front of the radiator, there is another radiator looking thing, it is the precharger/charge air cooler. Make certain that it hasn't been damaged or cracked.
    You said that the cam sensor was replaced. How long ago was that?
    If it was some time ago, it may have gone bad again.
    Also, on the driver's side there is a lifting eye bracket, next to it is the Injector control pressure sensor. Round sensor with a connector on the end of it. If you are able to locate it, unplug it and run to check. Let me know if it makes any difference.
    My last thought, hail mary pass, is that there may be a problem with the harness under the valve cover. The connector clip sometimes comes loose.


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