Cummins Diesel Repair in Colorado Springs | Westco Automotive & Truck Repair

Which Cummins do you have?

The engine in front of you decides almost everything about what to watch. The 5.9L 12-valve, the 5.9L 24-valve, and the 6.7L that arrived partway through 2007 are three different animals with three different weak points, and advice written for one of them can send you looking in the wrong place on another.

We work on all of them here in Colorado Springs, in pickups and in fleet trucks.

The CP4 fuel pump on 2019 and 2020 Ram

Based on what we have read and what comes through the shop, the Bosch CP4.2 high pressure fuel pump is the one that costs the most when it goes. The pump runs with very tight internal clearances and very little lubrication other than the fuel itself; when a roller or lifter inside it starts to wear, it makes metal, and that metal goes downstream into the rails, lines and injectors.

That is why a failed CP4 is rarely just a pump. It usually means the fuel system gets cleaned out end to end. Ram moved away from that pump after 2020. If you are shopping a 2019 or 2020 truck, this is worth asking about specifically.

The grid heater bolt on 6.7 trucks

On the 6.7, the intake grid heater is held by a bolt that sits in the intake path. From what we have read on these, the concern is that the bolt head can work loose over time and drop straight into the intake, which puts metal into a cylinder. It is not common, but the outcome when it happens is severe enough that it is worth knowing about.

It is also the sort of thing that gets checked while something else is already apart, which is usually the cheapest time to do it.

EGR coolers, turbo actuators and DPF

Going off what we see, the emissions hardware is where most 6.7 owners actually spend money. EGR coolers crack and leak, the variable geometry turbo's actuator and vanes get sticky with soot, and the DPF clogs when something upstream is already wrong.

The useful way to think about a clogged filter is as a symptom. Something is producing more soot than the system was designed to handle, and replacing the filter without finding that thing buys you time rather than a fix.

The 5.9 engines

On the 12-valve, the well known one is the dowel pin behind the timing gear cover backing out. On the 24-valve, the VP44 injection pump and the lift pump that feeds it are the usual conversation, since the pump depends on fuel supply for cooling and a weak lift pump shortens its life.

These are old trucks now and most have had something done. What matters more than the year is what the paperwork shows.

Booking

Westco Automotive & Truck Repair, 1130 Valley St Ste A/B, Colorado Springs, CO 80915. Call (719) 591-7743 or book online. Female-led, ASE-certified, gas and diesel, all makes. We do not perform delete work on emissions equipment.