Cummins ISX Holset VGT Turbo pics and questions

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Pappa Bear, Apr 30, 2011.

  1. Pappa Bear

    Pappa Bear Light Load Member

    Messages:
    105
    Thanks Received:
    20
    Joined:
    Dec 20, 2010
    Location:
    Springfield, OH
    I'm having trouble getting the boost I need out of my truck. The turbo is sluggish and does not get above 25-30 on a hard pull. With jakes on high at 1800 rpm I only get 15-20 lbs of boost. I get smoke and lag when I first grab a gear. I have an 07 (pre-dpf) KW T800 with a ISX 475/1850 365K miles. Changed the EGR a few months ago. I've had a tech run the EGR/Turbo test with the Cummins software and it checked out good. I checked the CAC and it held pressure fine. I checked the turbo actuator and it was leaking air. I changed it and the turbo controller as well. I can not find an exhaust leak in the manifold. Fuel pressure checks out good 300 psi at the gear pump while pulling a load. I don't want to replace the turbo unless I know it's bad. We took it apart today and it all looked fine. It all moved fine. There was a fuzz of side to side play in the shaft but barely noticeable. In and out was fine. The turbo seemed to whistle more after we put it back in. Maybe it will finally blow up and I can get a new one! In the mean time if someone can look at the pics and let me know if they see something wrong I would appreciate it. Also I want to recommend Young and Sons in Indianapolis, In. They had the best price on a Cummins reman by far and pay the ups both ways.
     

    Attached Files:

  2. Heavyd

    Heavyd Road Train Member

    Messages:
    3,896
    Thanks Received:
    1,597
    Joined:
    Feb 4, 2009
    Remove the boost sensor on the left side and see if it is completely packed with carbon.
     
    Pappa Bear Thanks this.
  3. ProduceHauler

    ProduceHauler Light Load Member

    Messages:
    231
    Thanks Received:
    19
    Joined:
    Apr 28, 2011
    Location:
    California
    change Exhaust Pressure Sensor located by thermostat housing. Clean the pipes too. If its malfunctioning - ECM doesnt allow turbo to "close". Then engine is slugish to build power and jakes are weak. Its a self-defense measure, VGT turbo is a beast from hell, older ECM calibrations were overlooking it causing massive blowouts
     
    Pappa Bear Thanks this.
  4. Pappa Bear

    Pappa Bear Light Load Member

    Messages:
    105
    Thanks Received:
    20
    Joined:
    Dec 20, 2010
    Location:
    Springfield, OH
    Thank you, I sprayed the boost sensor with PB blaster and will take it out here in a little bit. If the exhaust pressure sensor was bad wouldn't I get some codes? I'm not getting any.
     
  5. Sportster2000

    Sportster2000 Road Train Member

    Messages:
    1,050
    Thanks Received:
    260
    Joined:
    Jan 5, 2008
    Location:
    Indiana
    That would be a maybe, it could still be in "range" but it could be on the very edge and give you not so good performance. It hasn't set the code because it hasn't gone past that line that is set in the ecm to tell it to set the fault engine light.
     
    Pappa Bear Thanks this.
  6. Pablo-UA

    Pablo-UA Road Train Member

    Messages:
    7,147
    Thanks Received:
    1,315
    Joined:
    Oct 11, 2010
    Location:
    Borispol, Ukraine
    Sensor is electrically good, but reads wrong data, that's wjy no codes, ECM thinks exaust pressure is lower and that's why output related issues.
     
    Pappa Bear Thanks this.
  7. ProduceHauler

    ProduceHauler Light Load Member

    Messages:
    231
    Thanks Received:
    19
    Joined:
    Apr 28, 2011
    Location:
    California
    no, there was no codes until I broke it trying to remove it. It was getting water for some time and was giving HIGH pressure readings. Thing is I was not having smoke issue. EGR valve is next thing to look at
     
  8. Pablo-UA

    Pablo-UA Road Train Member

    Messages:
    7,147
    Thanks Received:
    1,315
    Joined:
    Oct 11, 2010
    Location:
    Borispol, Ukraine
    EGR is motor driven, motor is with small gear that moves EGR valve. and as I can see there is some ash in turbine so EGR valve may be stuck with ash, carbone deposits... and motor may cut teeth...
     
    Displaced Yooper Thanks this.
  9. Pappa Bear

    Pappa Bear Light Load Member

    Messages:
    105
    Thanks Received:
    20
    Joined:
    Dec 20, 2010
    Location:
    Springfield, OH
    Update: I removed the boost sensor it looked to be in good shape. I removed the tube that goes from the exhaust manifold to the manifold pressure sensor in the thermostat housing and blew it out with air. I changed the manifold sensor. Still not fixed.
    My turbo started to make more noise and leak oil where the vg crank arm comes out of the housing. So I took it into Cummins and they changed the turbo. They actually paid for half of it because my truck has less than 500k miles. It's a good will program they have going on. Truck was still not fixed though.
    So I took it to my shop and had them plug the computer in and go for a ride. The only thing he noticed was the ecm was not telling the EGR valve to do anything. When he ran the test in insite the valve responded fine. I thought this might be due to the bully dog program I had tried. When I sent it back I returned everything to factory settings but it must have left some of the custom programming from full tilt in there, that had to do with EGR. They updated my ECM to the latest from Cummins. I pull out on the road and sure enough 35-40 psi of boost! She's running good now... what a frustrating deal. Almost makes me want to by an old truck (less complicated). Either that or quit messing with this one :biggrin_25525:
     
    Strider and bossboy2 Thank this.
  10. ProduceHauler

    ProduceHauler Light Load Member

    Messages:
    231
    Thanks Received:
    19
    Joined:
    Apr 28, 2011
    Location:
    California
    Why did you return the BullyDog? What went wrong?
     
Draft saved Draft deleted