I just took my C13 to Holtcat
of Fort Worth after having the Check Engine light come on more frequently, and with a consistent pattern.
Under 90%-plus load for more than ten seconds, after at least thirty minutes of driving, the light would illuminate. I noticed no degrade in power, and dutifully copied the fault codes after each occurrence. The codes pointed to incorrect operation of two valve actuator solenoids.
'Turns out, I had three that were sticking and a bad pressure sensor in addition to that. Holt charged me $1,400 to replace all six solenoids, whose design has been identified by Caterpillar as deficient. They explained that it's not really a "recall," but termed a "product improvement." That's Caterpillar's way of saying, "You pay for this."
Not to whine: these valves are just $85 apiece, which seems more than reasonable, given their design. Since all of us incur a little more labor gaining access compared to tractor rigs, I had them "bundle" replacement of all six actuators -- they are sold in pairs for $170 -- into a single operation.
The foreman raised an eyebrow at my contention that I didn't suffer a derate. After all, I've had my C7-powered Fleetwood derate, and it was nothing short of dramatic. According to him, the C13 derate is automatic with those fault codes. Indeed, the rig performed differently on the ride home, accelerating up some hills that it lagged albeit only slightly on during earlier trips. Not a huge amount of difference, but detectable.
So, C13 owners might not be aware of a minor power loss in the wake of having valve actuator fault codes registered, during operation. If your engines have a history of occasional actuator-related faults, now might be the time to get these improved solenoids installed.