General consensus on Cat 3116 from 97-01 ?

SeaNile

Well-Known Member
Aug 16, 2010
1,514
Chadds Ford, PA
Boat Info
2003 50 Sundancer
Engines
Cummins QSM11
It's not even winter yet and I can't stop thinking about boating. Lots of options out there in the 40-42' range from 1996-2001 (my budget) and most, if not all, have the Cat 3116 engines. I remember 12-15 years ago of the bad reputation these engines had (soft block, etc) but how are they now? Figure if they were going to implode it would have happened by now? Safe to assume a 3116 with 1000 hrs has passed the point of failure? Yes, engine survey would be completed with oil analysis and all that good stuff.

I'd rather have Cummins or even Yanmar but it really looks like the 3116 will be in my next boat.

TIA
 
It's not even winter yet and I can't stop thinking about boating. Lots of options out there in the 40-42' range from 1996-2001 (my budget) and most, if not all, have the Cat 3116 engines. I remember 12-15 years ago of the bad reputation these engines had (soft block, etc) but how are they now? Figure if they were going to implode it would have happened by now? Safe to assume a 3116 with 1000 hrs has passed the point of failure? Yes, engine survey would be completed with oil analysis and all that good stuff.

I'd rather have Cummins or even Yanmar but it really looks like the 3116 will be in my next boat.

TIA
SeaNile,

Don't be afraid of the 3116 engines. There were two issues from the early 90's. 1) was soft blocks from a foundry in France. The other was bad valves from TRW. Both would show up by about 150-200 hours max. CAT warrantied and replaced these engines at N/C but ended the program in something like 2006 because they felt the system was cleared of the issue. Just make sure they have been taken care of and they purr right along. I burn 22.6 GPH @ 20-21 kts in my 400DB (for both engines). I am sure Frank W may add more detail to your question.

-S
 
SeaNile,

Don't be afraid of the 3116 engines. There were two issues from the early 90's. 1) was soft blocks from a foundry in France. The other was bad valves from TRW. Both would show up by about 150-200 hours max. CAT warrantied and replaced these engines at N/C but ended the program in something like 2006 because they felt the system was cleared of the issue. Just make sure they have been taken care of and they purr right along. I burn 22.6 GPH @ 20-21 kts in my 400DB (for both engines). I am sure Frank W may add more detail to your question.

-S

Exactly what I remembered. The first 300ish hours is when the issues would show up and the soft blocks were from France.

Lots of thinking to do if we decide to get another boat. The 40' seems to be the sweet spot for us from what I can tell. Under 40 isn't enough of a jump up from our 340 and over 40 is just too much for how we plan on using the boat. 1998/1999 400 SunDancer with the 3116 is a popular choice.
 
I went from a 340DA to my 400DB Sedan Bridge. Best thing I ever did. Absolutely no regrets. The view from above is amazing. I wouldn’t discount as DB model.
 
I had a 1997 400 DB with Cat 3116 and loved them. I am in a 480DB now. They are virtually bullet proof if you keep up on the service. Some people like to trash these engines due to the reported issues even though they have never owned a set of them. Those bad engines have long ago been replaced by Cat. I think there were only 500 or so bad engines and from what I have read (Don't quote me on that though). There are literally hundreds of thousands 3116 Cats out there, which should tell you something....it is a great engine. Good luck on the boat. These engines sip fuel compared to a lot of other engines.

Get the serial numbers off the internet of the bad engines and compare to the ones you are looking at. That will tell the story.

Keith
 
I've attended more than one Cat 3116/3126 survey, most done by very knowledgeable Cat mechanics. One thing I learned from that experience is that the 3116 did not have the soft block issue.......only the 3126 had soft blocks. Some 3116's did have soft valve stems but all were worked out of the system by about 2000 since the bad valves failed in the first 150-175 hours of running......this came from the Service Manager at Ring Power who was the Cat distributor for Sea Ray in Merritt Island. He has to repair the engines so he knew each and every failed engine.

Personally, I have run 3116's for 24 years and I love them. Easier and cheaper to maintain than 3126's, Cummins or Yanmar. I've only had Cat on my boat 2 times in 24 years and both trips were for scheduled maintenance and the service calls totaled less then $1500.

Don't be afraid of Cat 3116's....be more afraid of engines that have been overheated, and overloaded and do a mechanical survey.
 
I like the 3116 more than the 3126 simply because the aftercooler uses engine coolant; the 3126 uses seawater (cooler charge more HP).
The only significant downside to this series of engines is they tend to eat raw water impellers. Requires replacement each year and if in shallow water with sediment more often. My Cummins engine is year three plus on the impeller.
 
If raw water impeller changes are my biggest concern I am good to go. My Cummins 6BTAs use to eat a few every season. Talk about frustrating! Oh, the NextGen liked to chew them up too.
 
SeaNile,
I just sold my 2000 410 Sundancer with 1000 hrs on the 350hp 3116's. All I can say is I did not have one ounce of problems with those engines and according to the detailed maintenance logs that were kept throughout the boats lifespan there were no notable problems for the previous owners either. They were were clean burning, simple, and very economical. I can't say enough good things about the 410 Dancer with these engines. At 2300 rpm(analog tach) she would cruise at 25 mph while sipping fuel. The boat would consistently get over 1 mpg in favorable conditions running at that speed. The package you are looking at is a great combination of size, amenities, and performance at a very good price point. I will miss the 410 and due to my growing family we traded up to a 510DA so economy at any level is a thing of the past. lol.
 
I love the 3116's in my 2000 400 Sundancer. The boat sips fuel and has a ton of power that matches perfectly with the ride of this hull. A surveyor friend of mine calls the 400/410 the Prius of Sea Rays since they are so fuel efficient.
 
Thanks for the info but i've got more questions!
Looked at a 99 40 with the 3116 Cats, just under 1000hrs which has been maintained very well. Current owner has owned the boat for about 15yrs. When he bought the boat from a broker way back when he was given the receipts, proof of work, etc that the one engine had a head replaced. Zero issues in the past 15+ years....and 900 hours since the head was replaced.

So, should I be concerned about the other engine with a similar serial number has the original head? I have both serial numbers if that helps.
 
Wonder what the reason for the head replacement was? Either way if both engines have been problem free for 900+ hours with good oil samples and regular maintenance speaking for myself it would not concern me. This is assuming the engine inspections and sea trial reveal no hidden issues.
 
Both 3116 and 3126 are 3100 series engines. The two big differences between the 3116 and 3126, is the 3116 aftercooler is coolant cooled vs the 3126 raw water, and the 3116 is a 6.6l vs the 3126 7.2l (in the 3100 series, the second/third digit represents the cylinder displacment (1.1l vs 1.2l per cylinder) and the last digit, the # of cylinders, (both 6 cylinder engines).

Both are great engines and you will find many happy owners of each on this forum. I'd have a pair of either in my boat, but mine are 3126's and run great!!
 
So what about a 99 boat with 3116 and 475hrs? Low hours are attractive to me but this maybe too low for any initial problems to surface. It's a NE boat with short boating seasons.

Just thinking out loud as i surf the web waiting for a 40' to catch my eye...
 
500 hrs is well past the usual point of failure as I recall. Looks like it’s 20 hours a year, and in a place with a short season, not out of the question. Are there any service records? How many owners? Maybe the owner let it sit after a point for some reason, that happens.

The only thing that needed to be accomplished with CAT would be the 250 hour service where the rack and injector timining is reset. Can you confirm this was accomplished? Everything else is general maintenance, cleaning, fluid changes, anodes replacement.

If everything checks out I’d go for it.
 
Wonder what the reason for the head replacement was? Either way if both engines have been problem free for 900+ hours with good oil samples and regular maintenance speaking for myself it would not concern me. This is assuming the engine inspections and sea trial reveal no hidden issues.

Cat usually doesn't like to do head repairs in the field since they have their own remanufacturing facility. Most owners with any sense opt for a remanned head because it has has new valve seats, valve guides and injector seats installed in the remanned head. The 3100 series engines with unit injection system can fail due to either valve issues or injector seat leaks/failures.
 
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So what about a 99 boat with 3116 and 475hrs? Low hours are attractive to me but this maybe too low for any initial problems to surface. It's a NE boat with short boating seasons.

Just thinking out loud as i surf the web waiting for a 40' to catch my eye...


I will almost guarantee that a 20 year old Sea ray with 23 hours per year of use has suffered its share of deferred maintenance. Cat says change the oil every 250 hours or annually, which ever comes first. ......so does ZF and the generator mfg says 100 hours or annually.

I'd go by a Cat store and buy 5 ($13/ea.) oil change sample kits and sample the engine oil, transmission oil and genset oil before I got all ginned up about a real low time diesel boat.
 
Thanks Frank. Wish your boat wasn't too big for us! She's a beauty and hopefully will go to a good new home!!
 

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