Cat 3116 350HP - Good, Yes or No?

[Graham Lorimer]

May not be considered wise, but after much research, and reading many negative comments on the Diesel.com forum, I bought a 1997 DA with 3116 Cats in it two years ago.

I had the boat surveyed and the engines ran and performed exactly to spec. My quandry was like yours, do I then spend another $1500 getting an engine survery, which I believe includes running them quite hard, or do I go ahead and purchase, and then spend the money on a full service. The boat was in exceptional condition, and showed all the signs of having been very well cared for, if it was scruffy and needed lots doing to it, I may well have taken a different decision regarding the engine survey. I chose to buy and service, they had 800 hours on when bought, and are now just short of 1100 hours, and could not have been better. I seldom run at cruise speed, and never run at wide open throttle, ever!

I believe that the ability to run to spec is very important, and mine did. Also got an oil analysis done and have had several done since. All is fine.

Just my 2 cents worth.

Graham

 

[Dancin Dave]

I ran mine @2400 cruise and wot for 5 minutes after coming up on plane, always. I also would run @ wot for another 5 minutes just prior to any destination. This allows one to see how the boat is performing and if there are any possible issues before getting to far from home port. I have been advised by the CAT people that additionally running the boat @wot for a period of 5 minutes per 1 hour of run time would be acceptable.

 

[Lateasusual]

I've been told by many to run from these cat engines, though I just saw a nice 1997 40 sedan with a pair of them with 860hrs. What do I do?

I have a long history with Cat engines and I am VERY familiar with 3116, however not a lot of experience with them in a marine application. I bought a 1997 400DA with these engines even after hearing all the bad press. They are fuel efficient and run fantastic with 1100 hours on them.

I have been in the construction industry for 35 years and that's where my experience with Cat comes from. Cat put these same engines in heavy equipment and regularly the engines would get 10,000 hours of service in a very harsh environment. They're is two MAJOR differences in construction and the marine version.

In the construction equipment the power is turned down so in some manner they don't work as hard. These engines are not producing as much horsepower but they do run 8 and 10 hours a day 5 and 6 days a week in the heat and in VERY dirty air (due to the dust). The other thing to remember is most boaters don't use their boats often and the salt that is in the air does get in the combustion chamber and that is not good for ANY engine, gas or diesel. I believe those are the two main reason you don't hear of Cat marine engines running to old age, neglect and lack of use.

Have the engines checked out, if the boost is good and there's no back pressure in the crankcase you probably have found a boat with some of the most durable engines ever made. If the engines smoke that doesn't automatically mean you should runaway from the deal. Dirty fuel filters WILL make a diesel engine smoke and dirty filters are common in diesel boats that sit and don't get used regularly.

If you buy a boat with diesel engines use a good additive to keep the fuel clean and you will avoid most of the simple problems people have with them.

BTW, I don't know of ANYONE who can match Cat product support. They still support the 3116's.