Anyone know anything about these motors ? Specifically the 430hp/1550 ft lb version.
Any typical problems ? Are they basically reliable, or should I stay away ?

excellent motor, opinions will vary based on color preferance, I do prefer a ism/isx but thats because we own cummins... I have driven many c12's and like them alot. They typicaly have more a bit more torque than cummins due to a slightly higher compression motor.......................

the c13 (newer emission motor) sucks to work on since it has a twin turbo setup, i think like 16hrs to replace the water pump??:barf:



joe

Cat's are harder on fuel then the next brand's comparable motor, but unless it's a c7, it's usually a pretty good thing.

The C12 is a good motor if the GCVW is kept at 80K or less. 6-7 mpg is average from most trucks I have dealt with. Should be able to go 700-800K miles between overhauls.

The only thing I have seen as a common problem is oil leaks between the front structure and engine block.

Worked on one fleet that would have to overhaul their C-12s at 500k miles, but that was mostly caused by grosssing 92K GCVW, which is way too heavy for that engine, IMHO.

Good soild, very reliable engine. We have 3 of them at work, no real issues, other than having the crank position sensor fail on all three of them(no huge miles on 2 of them, other truck was bought used, and has 700K, had an inframe at 650...) 6-7 mpg sounds about right, even in our rather light application(tandem fuel truck, 20,000L tank, the high mile unit is a tractor) But, our trucks are all severe service spec, full lockups, 18 speeds, the whole 9 yeards, and they are not highway geared.
Don't get me started on a C13... They are a bitch to work on. But, I must say the only issue we've had with the 1 we have was the computer failing... And, the fact it ain't got the balls or fuel mileage of a C12 at the same power rating...

I drove for Double Eagle in Hesperia. We had 20 trucks with C12's. Every truck had major problems. I don't think any made 200K w/o a rebuild.

I know we were doing turbo's @ 70K, headgaskets @ 120K. One truck blew a rod out the block @ 180K.

These trucks were not abused and had execelant maintenance. All were turned in early due to problems. I personally sat in Death valley for 7 hrs waiting on a tow truck after the fuel pump primer blew out of the Inj Pump.


They did run pretty good. Set up @ 430/445 they would run with a 12.7 DD set @ 470. But the DD would out live them easily.

The most seen problems we had in the dealership was head gaskets. The C-12 seemed to have a clamping issue on the block. They aren't a bad engine. Did seem to be lower on the fuel mileage than the others, but still not bad. Cats also seem to live the shortest amount of time. It's not unusual to see a Detroit or Cummins make a million miles, but the cat will usually make 700K.

What year? Serial number? The early 3196's (Pre C12) were bad news with aluminium spacer blocks, and head gasket problems. Newer c12s are much better. They are still a little light on head gasket retention. Head bolts should be replaced every time the head is off, and it has a pretty technical torquing to the head bolts.

Cats are usually harder on fuel, but prefer to run at a slower rpm for thier peak torque/ and fuel economy. Cats usually are more pricey to work on.

How big of a truck? ORT, heavy weights? I would rather go with a C15 if running ORT/ or heavy. Just my $.02. Then again my dad's old 12.7 detroit will run with most trucks down the road, and pass the cat's when they stop for fuel.;)

Michael

This sounds like a more experienced/intelligent group than the usual ford/chevy debate....... so I'll ask a related loaded question (forgive the hijack)

I spilled my milk- own a 3126e, bought it 2 yrs ago with 5400 miles (truck was a 4yr old repo), now has 56000 miles on it. delivered new as 250/800, I have an edge box with 40/120 added (big help) engine has the 32qt pan, runs a fuller 6 speed, 3.90 gear, 2000 rpm is 76 mph. Truck gets otr duties grossing about 28k with trailer, running 1750-2100 rpm's depending on speed limits, schedule and Fuel$ . power is adequate for my use, but I will likely let Cat rerate it to 300/860 when I get around to it.

I realize this is not a favorite engine- but most seems to be because it's not sleeved/inframe capable (Are other comparble mdt engines in frame capable???) SB was done to upgrade the oil line, cat dealer did a diagnostic check when i bought it- all is good. At this rate, 20-25k miles a yr is expected. Continueing as I am- what should I expect- can I get 500k out of it? what does a new long block run when the time comes?

There are c15's in the trucks at work. Most times haul over 80k. Not had a bit of trouble out of them but they are just a couple years old and neither has over 100,000 on them.