2015 Pete 579. All opinions welcome please

Where do people find these Cummings engines?
Are they the red headed stepchild of the Cummins brand or the Chinese version of it?

 

What’s the mileage? Engine size and horsepower, Overall condition? Tires? Do they have a history file? Asking price?

Since this is your first truck, I’d bring my own mechanic to do a complete inspection.

Could be a very nice rig, but don’t fall in love with any one truck, they’re just a tool to make money with.

BTW - 2018 models use a Cummins ISX13 or ISX15, not exactly a Chinese Red Headed Step Child. Not sure if 2015 had the same choice.

Model 579 Features & Specification | Peterbilt On Highway Trucks | Peterbilt Motors Company

 

If there is a dyno near you, get it stressed before you buy.

I think my dyno was less than $300 with a DOT inspection.

 

Cummings vs cummins!
Get it?

 

That will be the Cummins CM-2350... There are fuel pump and liner issues with those motors. The fuel pumps are notorious for exploding and if not caught in time will take the entire motor out, including the block. The liner issue was supposed to have been addressed with the 2350, but has not. If the truck lugs, there have been cases of the liner, that is where the piston resides, drops.

The fix for the fuel pump is to rebuild every 300,000 to 400,000 miles. The rebuild kit runs around $400. The liner issue, if they drop, is basically an in frame. Liners will need to be raised and shimmed. A counterbore in the block will need to be done also along with normally a new head. Never use a reman head on these new Cummins motors. They fail in short order, they are disposable.

Personally, If you have to have an emission truck, I would look for a 2008 to 2010 with the Cummins CM-871. That is the dual camshaft motor, no high pressure fuel rail/pump issues. In frame it and head over to Rawze.com and fix the real issue. I have that motor, and it is fixed.

If I had to do it again, I would look for an old Series 60 Detroit or Cummins N-14. A Cummins CM-870 with EGR would also be a good motor, as the EGR issue is easily addressed with a bit of programming.

Emission motors will bankrupt you, I have been down this road and know of more than a few O/Ops that have been financially ruined by these trucks. They are not cheap to in frame either, to do it right. A basic in frame is $20,000. A full blown front to back will run roughly $40,000. And then you still have the emission issues, those costs can easily run into tens of thousands of dollars if not addressed and fixed quickly and are very expensive to keep in operating condition. Go to Rawze.com, there are a few threads over there right now on the CM-2350 engine failures. It is not pretty.

Just my .02

 

What exactly will a dyno tell you

 

A dyno is a waste of money on these new motors. You need to get inside and poke around, something a dealer will not allow you to do. Pop the top and inspect the cam and rollers, drop the pan and inspect the lower end. Test the EGR cooler for leaks, etc. And then records, these new trucks never have any service records. If a fleet owned truck, it was more than likely serviced every 50,000 miles, drastically shortening the life span of the motor and emission components.

Oh, speaking of emissions, the SCR tank, another area that needs to be inspected for cracks and leaks. When they fail, they mimic all sort of things. The first thing the dealers like to do is replace the turbo for $6,000 - $8000. When all that it needs is to have the SCR unit removed, cleaned and possibly spot welded. So many issues with these motors... And the fuel systems... Just a HOT MESS.

And they all have issues, no matter who makes them. This is not your grandpa's truck. Steep learning curve, mechanical skills, knowledge of the systems, diagnostic equipment, you need all of this to survive with one of these trucks if you plan on keeping it for more than a year or two, if it makes it that long without a major and costly failure.

 

I got it, do you?
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Right from the horses mouth!