MaxxForce Diesel Engine Troubles and Solutions

Mechanics Hub Forums Diesel Engines International (Navistar) MaxxForce Diesel Engine Troubles and Solutions

This topic contains 64 replies, has 1 voice, and was last updated by  Angel 1 month, 1 week ago.

Viewing 15 posts - 46 through 60 (of 66 total)
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  • #50213 Reply

    Michel Turcotte

    Never buy an Inter maxxforce is shit from American that got no respect!!!!

    #50228 Reply

    Justin Garvin

    I am wanting to purchase a 2008 dump truck in California with a 7.6 Max Force DT with 68000 miles. What do you think about the motor? Can an emissions delete be done and solve any problems?

    #50328 Reply

    chad jordan

    John, have you considered doing a egr delete? It sounds like the main source of failure is the EGR Cooler failing letting coolant into the oil causing dilution and ultimately engine failure.

    #50411 Reply

    Jeremy H

    Need some advice on purchasing a 2013 international with a maxxforce dt466 that the oil sample analysis came back as follows;
    There’s a lot more parameters and numbers on the sample analysis report but these were the flagged ones.
    Any recommendations or information would be helpful with my decision to purchase or not. I would be an end user of the bus and am not a garage or shop that could afford an expensive rebuild. Given the levels indicated would this be minimal wear that with a clean oil change and minor repairs the motor would last or are these high numbers indicating moderate to major internal wear/damage that indicates a rebuild is in the near future? Thanks for any input.

    #50422 Reply

    John Whelan

    Chad I’ve been told about the EGR cooler delete and I am tempted but can’t do it due to being a responsible government representative. If you don’t let the coolant get below the cooler core and keep the oil clean the failures will decrease. We started changing the engine oil and filters every 5000 km (3000 miles) and the results have been great so far. The oil samples are coming back clean which means less sludge to plug everything up.

    #50421 Reply

    John Whelan

    Jeremy don’t buy it! You might have a failed EGR cooler which costs a month’s pay for the average Joe. We have 18 Maxxforces in our fleet and have spent tens of thousands of dollars on the engines and emission systems. Look for a good unit 2006 or older non emissions and you will have a lot less trouble. If you want newer look for a Cummins ISB. Please mark my words I’m talking from experience. Good Luck!

    #50640 Reply


    If your Cummins engine is still under warranty, you can require service if any problems in the engine.

    Cummins engine generator:

    #50753 Reply

    Phil Underwood

    We have 3 of these Navistar powered tractors in our fleet. Same story #6 cylinder no compression.
    And obvious other injector problems and puck seals. Crazy how many problems these engines have with under 200k miles on them.

    #50793 Reply


    Does anybody know if you can bypass the two vacuum hoses on the EGR valve on a maxxforce diesel engine

    #50972 Reply


    2013 Navistar 4300 maxforce 7 We have installed 2 front main seals and continue to have a problem.We have the correct tool to there a secret?

    #50924 Reply

    Michael Robinson

    I bought a new 2013 terrastar come with a 6.4 L (389 cu in) MaxxForce 7 turbodiesel V8 around 60,000 miles I had oil pump failure, they warranted it out a new engine…144000 miles same thing. They (rush truck center) give me a 100,000 mile 2 year warranty but now they will not warranty it. The oil pressure had went down and I had them come out and check it they said it was just a sensor 20 minutes later motor cut off. Any legal information out there ?

    #51093 Reply

    Michael Michalski

    FYI, there is a specific thing that happens when coolant leaks into engine oil. The addatives in the engine oil combine with the coolant and precipitate out as hard spherical particles which forms an abrasive sludge. That is why people who change a bad head gasket often find that the bearings in the engine go out shortly after and conclude that coolant was corrosive to bearing metal. To make matters worse, they try to clean the engine by doing multiple oil changes. That won’t get the imiscible coolant out, but instead adds a fresh batch of adatives to precipitate more abrasive slide. The solution, taken from an old International Harvester tractor repair manual is to make a mix of 50% motor oil and 50% butyl cellosolve. I prefer to use 50w non detergent motor oil or 90w gl1 gear oil under the assumption that less adatives are good in this situation. Drain the contaminated oil and replace it (along with the filter) with the 50/50 mix and run it at idle for 20-30 minutes. Avoid racing the engine or putting it under load. The butyl cellosolve will allow the coolant to disolve into the engine oil and drain out when you change it. Drain the oil, and change the filter. I’m a bit paranoid and like to drain that mix out, replace it with sone cheap motor oil and a cheap filter, run it for another half hour and the replace it with a my preferred oil and filter to get all the butyl cellosolve out. Butyl cellosolve can be purchased from most chemical suppliers by the gallon (or 5 or 55 gallons) Once the oil is contaminated by a lwake between the cooling system, that needs to be done or you will end up with massive engine damage. It seems to me that on engines prone to that,periodic oil analysis (perhaos at each oil change) may be called for to spot the trouble before it becomes critical. I don’t know if the coolant tests for hydrocarbons used to spot bad head gaskets would spot the problems, but in a fleet of such trucks, it might be worth while to do the experiment and see if you start sporting the leaks before the engines die.

    #51182 Reply

    Shelia Matney

    Maxxforce 9 starts for about 5 seconds and won’t reeve up and then shuts off

    #51097 Reply

    Doug Greiner

    The only thing I can say is it says Maxforce Run. But if you do buy or own one I have a 2012 Prostar 12.8 that I’m parting out complete truck.

    #51301 Reply

    Jim Brock

    I have a 2016 N13 which is the maxforce with def. In the last 100,000 miles it has has a turbo, 2 High temp EGR’s, 1 low temp EGR 1 DPF and a host of other issues! it is a hanger queen no doubt! What it is doing now is it is collapsing the CAC hose! It is creating enough vacuum on the intake side (that should always be under turbo pressure that it is sucking the spring back into the hose allowing it to collapse. The dealer tells me everything checks out! I just spent $3200 on an issue that has never been corrected and since they can not find the cause it’s not under warranty! Still loosing coolant even after all the EGR’s were replaced. Burnes about 1 gallon of oil every 3000 miles which if you ask me is high consumption for a modern engine. Hell the old A model 3406 and any of the cummins NTC engined done better than that. But they insist it doesn’t have excessive blow by. It does have a slight pan leak and a slight leak at the accessory drive. Nothing to add up to that much oil. Hell I park it in my driveway and there are no oil puddles. I have a hunch it is the intake throttle valve or the waste gate on the turbo not closing. Runs just fine empty but under a load it falls on its face if you are not already under boost. Fuel mileage is also horrible! I have an APU so Idle is at a minimum yet when I figured out the fuel mileage for the year it was at 5.34 and that is not including the several time I fueled up with cash or my credit card because my fleet card was not working. Any comments that may help get this POS running right are deeply appreciated!

Viewing 15 posts - 46 through 60 (of 66 total)
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