Paccar MX or Cummins ISX

Who said anything about the body controller? I am talking strictly engine diagnosis here. As a dealer tech I have full access to do 98% of whatever is needed to these engines without asking for access. The other 2% I can usually get without a lot of explanation.

Let's talk engines.... we both know they use the same after-treatment as Cummins, if it a Paccar product so we can just throw all that out of this conversation cuz it's all the same ####.

My 2 cents on the engines. Used or new. If you need high horsepower, 550 to 600 no question the larger displacement Cummins is the way to go. But dont gryp about fuel mileage when your trying to pull a tank up a gosh darn mountain. MX will win the fuel mileage war hands down every time. In the end over the life of the truck what matters the most? Fuel savings.......just do the math. When used is brought into the equation all bets are off. If you buy a used truck with no maintenance records, shame on you. Take the thing in and get it looked over before you make the purchase. Most OO dont do their homework, buy a big bad KW or Pete that's been beat to death and then wonder why it cost them their life savings to keep it on the road. Ask yourself this? Why is this truck for sale? Cuz its gonna run forever and make me a ton of money........doubt it.

 

The air compressor does have a cylinder head service kit available thru Paccar parts just like the Wabco on a Cummins. I can get you a P/N if needed. Cat ET was only technically available for sale to TEPS dealers and fleets. Fleet version was watered down. If independent shop had it, it was not legal version. You can buy Fleetguard filters, but don't be surprised when your centrifugal filters bearings go out. They spin about 8,000 RPM faster with the Fleetguard filter. DAVIE has it's good points and bad like any OEM diagnostic program. I feel like it has way better monitoring capability vs Insite espically with crankshaft speed overview. Much easier to find a misfiring cylinder. I don't work for dealership, but small fleet around fifty trucks and I have access to PVP, Eportal/Rapido, and DAVIE. Warranty support has been better with MX vs previous Cummins ISX and less issues with MX vs the ISX for my fleet.

 

That is a ridiculous post Goodysnap, are you really trying to claim that lazy used truck buyers are buying abused Paccar motors but just getting lucky when they buy a Cummins?

And you are not comprehending what I am saying, I have said numerous times that the Paccar is a better engine (and I would say that for 500+ hp needs as well).

I am condemning Paccar the company for structuring their support for this engine in such a way as too completely disregard the needs of small operators; that is why Paccar engines are cursed in resell market and inferior engines command a higher price.

I have not dwelled on the Emission system because they are the same as Cummins and none are assured to work correctly; you just hope you don't get a turd.

You are the one that said Davie was designed to work with Paccars software, Davie requires no other software to do the little it can do; what it requires is permission from the grand overlord in the cloud E-Portal to do what you need it to do.

After a decade you can't keep saying "it's getting better all the time" and expect that to inspire confidence; most engine manufactures redesign their engines in less than a decade and Paccar is still trying get the bugs out of their support system?

These are not bugs, this is evidence of a business model that is trying to lock their customers into a service structure with no competition from the outside; this model has doomed every company that tried it to second tier status in spite of making outstanding products in many cases.

You are defending an engine that I am not criticizing, but I have seen nothing that would allow me to recommend a used truck buyer to choose the MX; conscience demands that I steer them elsewhere if they are buying used.

 

As of last month the air compressor did not have a serviceable head or relief valve, my dealer thought it did as well (even quoted me a price) but when I sent him the actual compressor number he said his kit would not work?

And I seem to be having trouble communicating that I think the MX is a better engine and that for new truck buyers who choose extended warranties it is a great choice.

This thread was about a used truck buyer looking for advice on what engine to buy; like many he is tempted by the far lower price of a used Paccar and the reality that Cummins powered trucks get snapped up very quickly and are harder to find as a result.

I am addressing this buyer class when I say there are very good and genuine reasons for this Market reality and I am trying to make sure that he knows what to expect if buys the cheap engine and depends on it for his sole source of income.

In my opinion the Paccar MX13 is the best class 8 truck engine produced today (except maybe the Mack engine, I have never been around those)

It is also my opinion that a used truck buyer will find the MX engine to be a very expensive and frustrating investment, not because it will break more often but because when it does have an issue you enter a living hell that ignites your money and saps your soul of the will to live.

If you're buying new with long warranties then great, Paccar will buy those parts as needed; but the used truck buyer will have a far different experience when he has to pay those dealer rates and those Paccar parts prices.

 

Yep, I found the same thing on Wabco's site but for compressor model" (4510)
912 518 103 0 both Wabco and Peterbilt said it would not work.

 

Mack MP is a pile of crap. Just Google Volvo/Mack injector cups. We run our trucks well past warranty and have less issues than the ISX. They key is we maintain them. Scheduled DOC/DPF cleanings, EGR cooler and air management sensor/tube cleanings and 20,000 oil change on tractors. Customer Eportal is $300 a year so you could look service and part info for your MX AND parts and wiring diagrams for your chasis. The average owner operator isn't going to need DAVIE, so they sell PAC link which is apple or Android based software that allows you to pull all codes from engine and chasis for around $300.00.

 

The thing with emissions aftertreatment is it isn't maintenance free on any HD engine platform. If you maintain the WHOLE system , it will treat your fair. I am from the country so I like to compare it to a septic system. From time to time, the tank needs pumped out like Ash needs cleaned out of your DPF. Now, if the kids flush something down the toilet and your leach bed don't work, you will have a tank always overfilling. This would be like bad injector, leaking HC doser, etc. Now your pipes get less efficient over time, so they may need snaked. Not a septic tank fault, but it is the first thing blamed. In an engine, anything it contact with EGR soot will need cleaned or replaced to keep it all working right. Have to take a whole system approach when dealing with issues. Take care of it and it will take care of you.

 

And some people think that their septic tank is "self cleaning" and wait til the John backs up to fix it and then whine and complain cuz it costs so darn much to clean up the mess.