Anybody have any thing good or bad to say about this engine. My boss is looking at truck that this engine it has about 225,000mi and 410HP the only thing he could find wrong with it is the rear seal was leaking but the dealer agreed to fix it.

They had some head gasket issues, with an updated bolt torque procedure. Also, that the low clamp force resulting from the "loose" headbolts would sometimes cause liner damage as well. SOME were known to lose their piston pin retainers and pile up the cylinder

...but, they ALL have issues, just that some have more than others ;0)

Overall, a pretty solid engine.

Thanks for the info.

It is excellent on fuel ! We have two Western star tri-axle dump trucks with C-12 and C-15 , if we are on the same job end of the day about
$20 different on fuel ( $2.49/gal) . 1 day-$20 5day-$100 you due the math.

I bet, with the proper specs, i could get the same, if not better mileage from C-15!
But of course, if you put it to the floor on a both engines, C-12 is gonna be a winner! :P

Never have had C-12, but from what i've heard, it's the most troubled CAT OTR engine... :roll:

The truck I drove had 567K mile on it we don't have to many problem.
For as it is very dependable.

Worked at a Cat TEPS dealer for truck engines.

C-12 is a good motor. Expect to do a head gasket and Cam/Followers between 750 and 1 million. These problems are common, ask around and you'll find out. Other than that, a good engine, the fixes are out so you will really only have to do them once.

The Co. I work for has a fleet of tri & quad axle dump trucks with Cat C12 engines.

They have proved to be very reliable & trouble free.

I might add that the company has a maintenance program that is very meticulous with oil & filter changes done on time, every time, and oil analysis.

I work in the shop, and drive them sometimes too, so I see both sides of the picture.

The C12 has good power & driveability too.

What would this cost to do?