Forum Discussion

Doug_E_'s avatar
Doug_E_
Explorer
Jun 26, 2013

Cummins 2005 ISL low power AGAIN!

What we thought was a sticking exhaust brake on our MH is now a, They don't know. The exhaust brake checked out good and functioning properly.
$515.67 later and Cummins West thinks it could be a faulty turbo.
We can start it up one time and we get full boost (35lbs.), stop for fuel and restart the engine and the boost will only go to (25 lbs.).
I asked if it could be an O2 sensor or an EGR valve, they don't think so.
Would just like it fixed so we can have the reliability back again.

Now they want to put it on the dyno and see if it will give low boost while it's hooked up to the dyno.
Class A
  • Ranger_Smith's avatar
    Ranger_Smith
    Explorer
    Jun 26, 2013
    Maybe Cummins West should call tech support at Cummins itself and see if they can figure it out instead of just throwing parts in, taking your money, hope that was the fix.

    Is cummins west just a distributor and repair facility out west or is it the company itself?

    Also from other threads here:

    You also have an O2 sensor which controls the fuel supply.

    Clamps from the charge air cooler was broken
    and the engine was sucking air and causing a low power situation
  • wny_pat1's avatar
    wny_pat1
    Explorer
    Jun 26, 2013
    Ranger Smith wrote:
    Maybe Cummins West should call tech support at Cummins itself and see if they can figure it out instead of just throwing parts in, taking your money, hope that was the fix.
    I was thinking the exact thing. Tech assistance is just a phone call away! You can even call.
  • Gasman_2's avatar
    Gasman_2
    Explorer
    Jun 26, 2013
    Check for leaking intercooler. Have them pressure test when engine at temp
  • hershey's avatar
    hershey
    Explorer
    Jun 27, 2013
    Not sure what Cummins you have but I'd trade my first born for 35 lb of boost :)
    Loosing boost usually indicates a hole or opening in the turbo charged air. My boost declined on a recent trip and there was/is a small hose, about an inch and a quarter diameter under the intake manifold that runs from the manifold to the compressor. Easy fix. Also the clamps where any hose is connected to the components in the charged air.
    Your being able to get full boost at times would indicate that there is something else causing the problem and not a charged air leakage. Let us know the final diagnosis.
  • Doug_E_'s avatar
    Doug_E_
    Explorer
    Jun 27, 2013
    Cummins West checked pressure on intercooler, I was told it held good at 30 lbs. They also checked all clamps, all were also good.

    Ranger Smith: Cummins West is a distributor and repair facility.

    Gasman 2: I'm thinking the same thing like electric or sensor not working correctly.

    Hershey: It's kind of freaky how one time I start the engine, full boost and the next time it is not. The tech told me 35 lbs. of boost on the ISL Cummins is correct. You wouldn't think loosing 10 lbs. of boost would make that much difference, but from a standing start it won't hardly get going. Granted we always pull a race trailer weighing 6000 pounds.
  • lfeather's avatar
    lfeather
    Explorer
    Jun 27, 2013
    My 2002 ISL 370 has never produced more than 23 PSI of turbo boost and ithas plenty of power.
  • Doug_E_'s avatar
    Doug_E_
    Explorer
    Jun 27, 2013
    Ifeather: I appreciate the fact that your 2002 ISL has never produced more than 23 lbs, of boost and that's plenty of power for you.

    However when new my 2005 ISL produced 35 lbs. of boost and now it has less, almost no boost when trying to go from a dead stop.

    The tech at Cummins West confirmed that it should be producing 35 lbs. of boost with the VGT turbo when working properly.
    Thanks for your input though.
  • lfeather's avatar
    lfeather
    Explorer
    Jun 27, 2013
    Doug E. wrote:
    Ifeather: I appreciate the fact that your 2002 ISL has never produced more than 23 lbs, of boost and that's plenty of power for you.

    However when new my 2005 ISL produced 35 lbs. of boost and now it has less, almost no boost when trying to go from a dead stop.

    The tech at Cummins West confirmed that it should be producing 35 lbs. of boost with the VGT turbo when working properly.
    Thanks for your input though.


    Doug

    I understand and believe you, No offense intended. I'm just curious about the disparity? Maybe it's year-model?

    Larry
  • steveownby's avatar
    steveownby
    Explorer
    Jun 27, 2013
    lfeather wrote:
    Doug E. wrote:
    Ifeather: I appreciate the fact that your 2002 ISL has never produced more than 23 lbs, of boost and that's plenty of power for you.

    However when new my 2005 ISL produced 35 lbs. of boost and now it has less, almost no boost when trying to go from a dead stop.

    The tech at Cummins West confirmed that it should be producing 35 lbs. of boost with the VGT turbo when working properly.
    Thanks for your input though.


    Doug

    I understand and believe you, No offense intended. I'm just curious about the disparity? Maybe it's year-model?

    It is year model. The first serious EPA requirements went into effect for over the road diesels in '04. In late '02 Cummins begin to introduce up dated engines to meet the standard. Between the end of '02 and Jan '04 Cummins put new fuel systems and VG turbos on most of their engines. Boost went up, temps went up MPG went down. It was the first of many requirements.
    Larry

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