I don't know anything about the C-13, but I have to ditto the '01 C-15 comments. We've had one since almost new and it's been the most trouble free engine we've ever had. Nothing done to that engine except an alternator.

However, we also have an '05 C-15 Acert and it just broke a rocker shaft. Tear down also revealed a broken injector spring.

By comparison, the 1995 N14 ate injectors for a long time. '98 M11 liked head gaskets (still does). '01 DD60 liked oil (million miles). '08 ISX eats injectors and a turbo and drinks coolant and has had required several ECM reprograms in it's short life.

By the way...what is an actuator?

I don't know anything about the C-13, but I have had better service out of my CAT's than any other engine that I have owned. You can have problems with any engine. I have found that many of the problems that are associated with a particular brand of truck or engine is more of a driver problem or how it was maintained. My CAT's are 3406E's. I could not ask for better performance from an engine. I would consider another brand of engine, but would give preference to the yellow engine. I get better fuel mileage on both of these engines than I did with my last Detroit 12.7. I consistantly get over 6 mpg with both engines. My last Detroit did not get more than 5 mpg. Personally, I think that CAT is the most reliable engine made. I would not be afraid to buy the C-13.

What year was the 3406E and what year was the 12.7? I bet the Detroit was post 2003?

One 3406E is a 96 and the other is a 98. The Detroit was in a 91 Peterbilt.

Cats have a valve actuator that is operated by a solenoid, the plug to the solenoid is prone to go bad giving you a failed actuator code, usually, you just need a new plug, cost is 12 bucks for the part, about 30 minutes labor to install. I had mine replaced at Peterbilt In Jeffersonville In. the total was $112.00

So what....this $12 part causes valves not to open?

the way I understand it, it just assists with the opening, the valve doesnt open correctly if it gets improper voltage which is what happens if the plug is bad

Funny how things work sometimes. Not funny ha-ha, but funny strange.

Today, I'm starting to learn all about these (VVA's) or variable valve actuators. They started on the Acerts and they are responsible for holding open the intake valve a little longer. Not sure if it delays closing event or starts opening sooner but anyway, it is an Acert thing and is designed to reduce Nox levels.

Anyway, the mechanic says I have a cracked cylinder head and he thinks it was caused from a piece of the broken VVA housing getting wedged in between the cam shaft and the cylinder head, causing the head to crack. Truck went in last Fri to repair a broken rocker shaft (common Acert problem apparently). Tear down also revealed a broken VVA housing and broken injector spring. Now we have a cracked head.

Acerts suck.

Thanks for all of the feedback. It is good to hear everyones personal experience. I also talked to six different mechanics and many driver friends. Bottom line is that I am staying with the ISX as the best of the less than perfect choices.

Parts should be less with Cummins and CAT. I have a friend who loves his N14.