Exhaust Back Pressure at Idle . Turbo boost spiking

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Brandon0928, Nov 28, 2022.

  1. Brandon0928

    Brandon0928 Light Load Member

    176
    98
    May 14, 2022
    0
    X15 CM2350 X114B
    Having exhaust back pressure at idle. Doesn’t matter if engines cold or hot. At 700 rpm it’s not very noticeable but you can hear the turbo boost intermittently. At 800 rpm boost goes up to 10. At 950 goes up to 20. When idle reaches 1000 it goes away. Seems as there is a rattle in the valve train (been the way since I bought the truck)

    Engine has 660,000 miles. Rebuild at 590,000. Bought it at 640,000. New emissions during overhaul.
    I just got insite and have done the rail leak test. 288 drop in 60 seconds. Did the cylinder cut out test and it passed. Just now did a forced regen to make sure it would complete one. Completed regen in about an hour. I have geo tab and it has been showing a constant active regen.
    Insite shows no fault codes.
    Parts I’ve replaced
    Inlet Nox Sensor 11-16-22 due to code 3725
    Air filter
    Crankcase pressure sensor
    Egr Differential Pressure sensor
    Dpf differential pressure sensor
    Exhaust gas pressure sensor
    Intake manifold air pressure sensor

    - from egr cooler inlet to the intake I took off all pipes and cleaned them with carb cleaner. I replaced the egr cooler inlet gasket, and all o rings and seals to the intake. Replaced all CAC hoses and clamps.

    Exhaust outlet pipe replaced with Part # 5579020 when I first got the truck. 644233
    Bellow pipe was replaced as it was leaking and sending smoke into the cab at 655,616

    RIGHT NOW.
    — after regen truck is idling on its own at 800rpm. Usually always idles on its own at 700. I always bump it up. So with the truck idling by itself at 800 I’m not getting the exhaust back pressure with turbo boost spiking. Bump it up to 900 and still doesn’t do it. No change at 1000rmp. Usually when it idles at 700rpm and I bump the cruise up 1 notch it goes up to 800. Now with it idling at 800, I bump it up 1 notch it only goes to 830.

    What do I do next ? Is there a way I can send info from insite to someone to look it over to see if something’s out of line? Appreciate all the help I can get.

    -This all started after I got the 3725 code-
    I did send in an oil sample and it came back good

    Shut the truck off for 30 minutes. Turned it back on. Idle at 700 like normal. Bump cruise up to 800. Turbo isn’t boosting. Let it run for a little bit and get back in the truck and idle is back up to 800. Turbo wasn’t boosting but sounded like maybe it was just a tiny bit.

    posted on rawze earlier. just looking for all opinions and if someone had something similar happen to them and what the fix was
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Diesel Dave

    Diesel Dave Last Few of the OUTLAWS

    6,065
    8,878
    Jan 20, 2010
    Hesperia, Ca.
    0
    Seems I read this post before. Is this a double post ?
     
  4. Brandon0928

    Brandon0928 Light Load Member

    176
    98
    May 14, 2022
    0
    I made a post similar to it. But now after cleaning all the egr pipes and replacing all the sensors I’m just wondering what’s next
     
    Diesel Dave Thanks this.
  5. Diesel Dave

    Diesel Dave Last Few of the OUTLAWS

    6,065
    8,878
    Jan 20, 2010
    Hesperia, Ca.
    0
    I would just run it. If you have no codes, run it. I’ve had my my ISX 15 for 2 years and still trying to get used to it. At times idles a little rough and other smooth. When it wants to do a Regen, at first I thought I was losing the engine :rolleyes:. I noticed at idle(I kick mine up also)that the turbo at times is whistling and at times not. I’m to a point if there’s no check engine light or fault code, i just run it.
     
    Brandon0928 Thanks this.
  6. Brandon0928

    Brandon0928 Light Load Member

    176
    98
    May 14, 2022
    0
    I think that’s the only option at this point. Just keep up on everything and hope for the best! Im just surprised that there’s no fault codes of some sort. I did notice when I opened insite when I wasn’t connected to the truck to view logs when I opened it up it said “ A Fuel System Fault has occurred which may cause Trip
    Information Data to be incorrect. Troubleshoot fault codes as
    necessary, Do not replace the ECM. Resetting the Trip
    Information data will clear this message.”
    But when I was looking for faults there weren’t any
     
  7. TruckerPete1990

    TruckerPete1990 Road Train Member

    8,422
    4,914
    Jul 16, 2012
    Bentonville Arkansas
    0
    That means nothing just reset it and it will be fine. The boost at idle also sounds like its doing a ash regen. If you have insite what's the dpf history looking like?
     
    Crude Truckin' and Brandon0928 Thank this.
  8. Brandon0928

    Brandon0928 Light Load Member

    176
    98
    May 14, 2022
    0
    I just got insite . Not familiar with it yet. I’ve been trying to find a video that goes over everything for insite. I’ll look more specifically into that
     
  9. TruckerPete1990

    TruckerPete1990 Road Train Member

    8,422
    4,914
    Jul 16, 2012
    Bentonville Arkansas
    0
    Been awhile since I looked at after treatment stuff but should be under ecm diagnostic or ecm test and look for after treatment. Should give you the last 10 Regens. Also don't keep performing Regens if it goes into a shop and they look at this and see oh hey it's regening every 30 hours ur gonna end up wasting time and money lol
     
    Crude Truckin' and Brandon0928 Thank this.
  10. Brandon0928

    Brandon0928 Light Load Member

    176
    98
    May 14, 2022
    0
     

    Attached Files:

  11. TruckerPete1990

    TruckerPete1990 Road Train Member

    8,422
    4,914
    Jul 16, 2012
    Bentonville Arkansas
    0
    Looks good I would just run it. These emissions engines do weird things at weird times. Unless you log it while it's doing one of those weird things it's a guessing game.
     
    Crude Truckin' and Brandon0928 Thank this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  • Draft saved Draft deleted