International MaxxForce DT EGR Valve Trouble

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This topic contains 8 replies, has 4 voices, and was last updated by  Mike 6 months, 1 week ago.

Viewing 9 posts - 1 through 9 (of 9 total)
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  • #25962 Reply

    John Whelan

    I want to share a problem we’re having with low power no codes on our Maxxforce DT engines. The power loss is caused by the EGR being stuck open. It’s serviceable and can be cleaned up on the housing and shaft so it moves freely again. The new valve is reasonably cheap with no core charge.. Another step we follow through with is anytime the air induction system components are worked on or replaced a mass air flow calibration has to be done. This we have found makes a huge difference with the power.

    #29282 Reply

    Yes John I have already had this problem with the maxxforce DT engine’s. I haven’t noticed any problems with calibration. I don’t know about you but I have found that brake cleaner is the best to clean the valves with. Do you have any trouble starting those engines in the cold? We have found that anything below – 10 celcuis and you can’t get them started without the block heater turned on. The last two I/C busses that came in have the 6.7 liter Cummins in them ….. very nice improvement.

    #29294 Reply

    John Whelan

    We haven’t been cleaning the valves just replacing them if they have any problems. The buses come with diesel heaters and block heaters so cold start up is pretty smooth. I’m loving the ISBs they are giving us no grief whatsoever

    #29295 Reply

    andy dugan

    Hi Will, have you checked the operation on the intake heater element, check current pull and voltage. If you access to servicemaxx you can run a heater test. Put amp clamp on main red wire at back of manifold and check. Have had couple of burnt out heater, have voltage but no current pull.
    Yes ISB is vast improvement over DT in a School Bus

    #29296 Reply

    John Whelan

    Andy does servicemaxx give any code for the intake heater? What year of DT is giving you intake heater problems?

    #29300 Reply

    andy dugan

    Have never seen any codes for intake heater, mostly the 2010 emissions engine., I guess that have to use the heater more , to get around emissions the timing is changes so much on cold start the heater becomes much more important, Also been finding lots of plugging on the heater coil, mostly from the soot due to the EGR. The DT is way passed its sell by date, thank goodness that IC/IH started to use the ISB.

    #29306 Reply

    I don’t think the heater is an issue because we have two of those buses and the school board has one and they all act the same way. I have tried cycling the heater multiple times like I had to with the 6 liter I/H but no difference. I find that the engine turns plenty of fast but won’t make an offer. It will make a small attempt after the heater goes out but that’s it. We have the servicemaxx program so I will check the heater operation when I get on in the shop again. Our buses are 2013 John.

    #47382 Reply

    Miguel gonzalez Bautista


    #49674 Reply


    Have 2010 maxforce dt 466
    Replace coolers and hit sude went down 2 times looks like i have bad egr valve wuch caysed the cioler fail.
    But nit sure hiw test if egr valve is cloged o bad all i think is that the problem i ve noticed sometimes looks like runing and pluged sistem lot lost power.

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