Cat 3116 & 3126

Still in the market for a boat. Seem a lot of the ones I consider have either the 3116 or 3126. I understand longevity has a lot to do with how it was run in the past and keeping up with normal maintenance. Just wondering how many hours a well run, maintained engine will last. Do you have one of these engines? Would you care to let me/us know how many hours you have? I think there are many with 3000-4000 but how many have gone past the 4000 hrs. mark. Just wondering.

Heavy usage (over propping and running near wot), poor installation (bad exhaust design allowing water into the engine) and lack of proper maintenance ruin more marine engines than high hours do.


David

Forgetting all the installation nonsense, I have worked on a few with 8,000+ .

Hard question to answer given that a low percentage of marine diesels in pleasure boats die from hours related failure in the first place. Relatively few pleasure boats in that age group reaching that number as well. Can’t trust a rule of thumb based on hours when that number is going to be based on a low sample rate. It’s basically unanswerable.

I’d be looking for general condition and the only hour condition that was likely to ring an alarm would be low hours.

Cats in pleasure service are usually rated in the 20-30K gallons of fuel range. So hour wise, the distance between scheduled overhauls is a lot, certainly a lot more than 4K hours.

Doesn’t mean you won’t be spending serious cash on engine work in practical experience, just saying it is low probability that it will be based on predicted hours. Spend the money to zero the cooling system tip to tail and you will be ahead of the game.

Thanks for the replies although not many out there with higher than 4000 hrs with an exception by Arc who has seen 8000 - wow! Ghost, not sure what you mean by "zero the cooling system tip to tail?" Assume you mean make sure the engine is maintaining the correct temp at all rpm levels? Or maybe start from scratch and change coolants, thermostats, belts? Please elaborate , thanks.

There is a TF member named Hmason who has a GB46 named ‘Magic’ with CAT 3116, with hours close to those numbers you were talking about, and Howard speaks very highly of those engines.

Hmason, are you watching?

Hamish.

Pat T
Suggest you go to boatdiesel.com and read archives about engines in question. Once you've got a specific engine brand, model and details post a question there. The Cat guru is Dave, a very smart well informed expert. BTW, the $25 entry fee will open doors for all marine engine questions and propulsion systems.