579 MX13 tips, tricks and advice

Don't know much about the paccar but the newer ones are suppose to have less issues than the older ones. Hope you have good luck with yours

 

Get rid of it unless you make some modifications to the system choking off the exhaust. MX-13's are money pits if you don't keep a sharp eye on them and drive them right.

Idle speed should be between 1100-1300 rpm at all times, if you start getting notifications on the dash of high exhaust system temp warnings, or check engine lights, bring it up to 1300-1400 rpm to let the DPF clear itself better. Never, ever, ever dead-idle a Paccar, unless you want to decrease the service window for the DPF.

Try to avoid any idling when possible, they don't like to idle for very long and the engine fan is very loud. They will start as cold as -4°F without needing to be plugged in so you can stay warm most of the winter with a bunk heater or APU if you aren't traveling to Canada.

They aren't horrible motors, but they are not the best. If you are pulling a van on flat roads well under 80,000 lbs gross, you'll be fine and get really good fuel economy (7-9 mpg range). Once you get into some hills or heavier weights, you are going to struggle a lot.

My company runs a bunch of the MX-13's from 2014-2017 date range (both 579 and 388 trucks), and they do great in the US, even up to gross max, but as soon as they start going heavier (Canadian gross max with a tridem is 100,000 lbs) and into the hills, fuel economy drops out the bottom, and 550 hp C-15 Caterpillars from 2002-2007 in 379's get better economy.

 

Gearing would fix that wouldn't it?

 

I have to laugh a little here at the misperceptions lf this engine. I have a 2014 579 with the 500/1850 Mx13, 18spd and 3.91’s with about 370,000 miles on it. It’s had the odd electrical gremlin but has never had to be towed in. The engine has needed no work, just general maintenance.

It does light duty work most of the time but for bout 6 months I was running 140,000lbs in the Rockies (BC-Alberta) and it did great. I’d get passed by Cummins 550’s and DD16’s but it held its own against everything else.

Guys say the jake is pathetic, it’s gutless, blah blah blah, it’s not true. The jake is weak compared to an ISX but so is every other engine. It jakes as good as a DD15, DD16, a 05-07 Acert Cat (which was rated at 600 jakong hp), you get the idea.

The drawback of these engines is they are not easy to work on, thus more time consuming to diagnose problems and fix them. The bonus is they rarely have a problem.

My warranty is going to expire on this engine in a year. For any other engine thisnwoild scare the crap out of me but not this one. It’s stout and I have no reason to suspect that it won’t continue to give me excellent service, it’s the rest of the truck that tends to give me grief.

 

About the 579 or any mid roof in particular. Why not put one more bunk, or a cabinet on the back wall. And while I'm dreaming. Why not make the fridge no matter what side it is on, be a tall standup fridge so we can have a real size freezer, and more room for produce in the cooler. I jest my dreams never seem feasible.

 

I am following this thread with interest as I have just ordered a 579 myself. Expecting delivery in Aug/Sept with luck. Paccar MX 510hp
1850 with 18spd and 3.36 rears. It also has the new Ultraloft 80" integral sleeper and I am really looking forward to it being ready.
I am trading in a 2016 Volvo VNL 780.

 

I just did some more research and as far as I can tell the mx13 and mx11 engines were made by DAF Trucks. In Europe and are quite popular in Australia also. But Paccar had to partner with DAF to get the engine use rights.

 

You need to read a little more.
Paccar owns DAF.(so no need to ask the rights)
The MX's were developed by both Daf and Peterbilt/KW.
The 13L or MX13 was first used in 06 in the EU.No DPF or EGR but with SCR(DEF).
Best to do a yearly overhead.
Underlaying cam.

MX11 was built as a DPF,EGR and SCR engine.
Overhead cam.

Neither off those engines are racehorses.
If you want to be king off the hill........................don't buy either off them.
If you want to earn money..............they are great workhorses.

 

Thank you for the help.
I still find it interesting that the 13mx is a pushrod engine in this day of overhead cam being the normal thing.