cm 871 turbo questions turbo lag

Discussion in 'Trucks [ Eighteen Wheelers ]' started by tinys trucking, Mar 29, 2014.

  1. tinys trucking

    tinys trucking Bobtail Member

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    09 cm 871 446k on it now. Just purchased back in jan from pete was a paclease truck. Ran into issue with egr at 440k. Was throwing a code for the doser reaching upper temp limits. It also started to clog up the oil filter with soot at 442K and low oil pressure. At 442k I cleaned the egr system and replaced the doser, egr temp sensor, egr pressure differential sensor, and the intake manifold air pressure and temp sensor. Also found an exhaust leak at the flex pipe and replaced the gaskets to seal it all up. I pulled the egr valve and cleaned it as well. It was moving freely. No issues with losing coolant. Just as I read from rawze my check engine light went out after about 400 miles. also replaced crank case filter, fuel filters at this time and did full service. Also replaced coolant with new. Mileage went from 3.9 to 4.3.

    Now at 446k I'm getting a turbo lag. If I'm on the throttle and let off as I'm going down a hill then just lightly get back on the throttle its like the engine is labored and won't pull till after half throttle and it takes a few seconds. I'm running in the mountains on the back roads and state hwy so no real freeway time. Constantly on and off the throttle all day long never get above 50 mph. I'm pulling a big scrap dump bucket empty ay 42k and loaded at 80k. Only do about 300 miles a day. I'm also getting a high exhaust temp warning if I end up coming to a quick stop during a pull. There have also been a few times when I get off the throttle I get the belching through the turbo. Mileage last week was back to 4.1.

    No computer tuning all is stock on the truck full emissions system intact.

    Any thoughts or Ideas?

    Thanks Tom
     
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  3. Helowrenchturn2

    Helowrenchturn2 Medium Load Member

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    You said you are getting high egt. What's your boost reading? A worn out turbo can cause lag and hight egt. If you aren't boosting I would check for leaks and inspect for damaged guns on both sides of turbo. Also check for play in the shaft that will cause the wheel to contact housing
     
  4. Helowrenchturn2

    Helowrenchturn2 Medium Load Member

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  5. Oscar the KW

    Oscar the KW Going Tarpless

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    I was gonna say, were did you buy your turbo from? I might want one of them myself.
     
  6. tinys trucking

    tinys trucking Bobtail Member

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    checked fins and play in turbo 2 weeks ago when we did the egr cleaning all was good. did not pull the vvt assy off as no computer to reset it. Yes all boost leaks were fixed. ( took two tries lol) bad clamps
     
  7. Cat sdp

    Cat sdp . .

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    Are you sure the hest light isn't on because the thing is regenerating ..... The turbo lag might be unrelated ??
     
  8. tinys trucking

    tinys trucking Bobtail Member

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    Is there a way to inspect and verify that the vv ring is moving with out the computer? acts like my old dodge with the big turbo on it. I dont have a boost or egt gauge on it. the high exhaust gas temp was a code that was pulled with a scanner when the check engine light was on. No lights are on now.

    Oh I think I understand what you are saying now. When I'm getting the light when I stop short on a hard pull. I need to get gauges on this. Hate being the broke new guy but trying to just make all the bills right now. Bad winter!!!!!
     
  9. vangtransport

    vangtransport Heavy Load Member

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    The CM871 has a electronic actuator as you probably know, verifying if the VGT is in the correct position is not possible without Insite. Unless you have access to to Insite, I would bring it in and have a shop check the VGT & actuator. You've checked everything else accept what readings you are getting from your sensors. Any of the sensors that Rawze has suggested you clean can also be bad or going bad. Rawze has given great advice, but remember he has Insite to verify his sensors are working correctly.

    Just to add, without Insite I am pretty much guessing, if you have a specific fault code # it helps a little.
     
  10. tinys trucking

    tinys trucking Bobtail Member

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    I just went and replaced all sensors rawze said to clean. Guess its time to go to the shop. I just wish it was throwing a hard code so I don't get the nothing is wrong check please. I drive it all the time and I know something is going bad just not bad enough for them to find it yet.
     
  11. vangtransport

    vangtransport Heavy Load Member

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    Just one other thing after reading you original post again, have you ever had the DPF checked for flow?
     
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