Cat 3116, good, bad, problem area?

Not much good to say about them. They had a bad start in life and was eventually replaced with the 3126.
At best, was just a bit better.
IMO, Nothing I would want to put a lot of money into for cruising.

the 3116 are only part of the problem… they re in an old carver!

The big problem was the French made soft block 3116. That was decades ago and they typically failed within the first few hundred hours. Those motors are long gone.

CAT eventually replaced it with 3126. A strategy CAT has used with “problem” models throughout it’s marine diesel line since then.

But the 3116 seems to have gotten the harshest criticism of them all. Some of that is undeserved. Bottom line, decades later there’s a lot of non French block 3116’s still in service out there. They’ve been running for decades.

They’re going to have the same issues as other marine diesels in brokerage boats of the same age. All the usual suspects …heat exchangers, water pumps, after coolers, turbos, all subject to needing attention. Oil samples, performance to rated RPM etc etc etc. You know the drill.

As an aside, I know of a boat with a pair of 3116’s with over 8,000 hours. A few years ago it sank at the slip. They raised it and pickled the motors. Now, years later those 3116’s are still in the boat and still running. In this case I don’t think you could ask much more from those motors.

Shouldn’t. There are many 350hp versions out there as well.