3116's vs 3126's in a 40' Sundancer
- Thread starter oarwhat
- Start date
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
You are looking at boats that are roughly 15 years old, so, at this point in time, there are no horror stories since Caterpillar long ago fixed or replaced all affected engines they knew about. Your concern now should be t he same as anyone else shopping for a diesel powered boat.......i.e maintenance up to date, verifiable service history, no history of overloading or over heating, etc.
I am leaving home for the evening, and am out of time. If you want more information, I can give it to you tomorrow.
I am leaving home for the evening, and am out of time. If you want more information, I can give it to you tomorrow.
aquadancer
New Member
For the last 8 seasons and over 600 hrs my 3126TA engines received regular scheduled maintenance and clean fuel. Unscheduled repairs consisted of a blown out oil pressure switch and flaky temperature sender. Engines fire up instantly even after winter lay-up, don't smoke, don't leak (except when the oil pressure switch blew out - very messy incident) all while delivering reasonable performance and pretty impressive fuel economy. I read horror stories too, but it that was not my experience.
Moreover, my local CAT dealer is very good and very responsive (but unfortunately also very expensive)...
Moreover, my local CAT dealer is very good and very responsive (but unfortunately also very expensive)...
- Jun 2, 2008
- 5,024
- Boat Info
- 1998 450 Sundancer, Achilles dinghy w/15hp
- Engines
- 3126 Cat's
My 3126's were part of the CAT recall. They replaced the blocks in '02. They had 300 hours on them @ that time and I bought the boat in '07 with 600 hours on the meters (only 300 on new blocks). The boat now has 1200 hours on it and they have been great. Very dependable and pretty good fuel economy....
Guys thanks for all the input so far keep it coming. Frank I am interested in more info please post when you can. I'm helping a friend looking to purchase a 400 or 410 Dancer. He's never had a diesel boat. I've owned two and worked on many diesels but never the 3116 or 3126. So I only know what I've read on boatdiesel, etc. I'd like to hear from more actual Dancer owners. Again thanks for all the info. Randy
peterkvs
Active Member
No Diesel engine in a pleasure craft has ever died from being worn out, they've all died from neglect.
I have a 99 400DA with 3116 Cat diesels. When I bought the boat I knew little about the engines or their history. I did all the maintenance items on the engines required from 0-750 hours to establish a maintenance baseline. I replaced the fluids, flushed the engine and raw water side, replaced the water pumps, removed and cleaned the aftercoolers. I had Cat come out and do the overhead adjustment and generally check over the engines. I've had no issues with the exception of a leaky primer and a bad fuel solenoid relay. They are simple mechanical diesels and that is what makes them so reliable. Another big plus is they use half the fuel of gas engines and have roughly 5 to 10 times the lifespan of a gas engine when well maintained.
Good luck.
Pete
I have a 99 400DA with 3116 Cat diesels. When I bought the boat I knew little about the engines or their history. I did all the maintenance items on the engines required from 0-750 hours to establish a maintenance baseline. I replaced the fluids, flushed the engine and raw water side, replaced the water pumps, removed and cleaned the aftercoolers. I had Cat come out and do the overhead adjustment and generally check over the engines. I've had no issues with the exception of a leaky primer and a bad fuel solenoid relay. They are simple mechanical diesels and that is what makes them so reliable. Another big plus is they use half the fuel of gas engines and have roughly 5 to 10 times the lifespan of a gas engine when well maintained.
Good luck.
Pete
MARGEEZ
New Member
- May 12, 2014
- 38
- Boat Info
- Freedom Boat Club while looking for next yacht
1997 SeaRay 420 Aft Cabin
2008 Rinker 350 EC
- Engines
- Cats 3126TA ~1400 Hrs
Mercury Seacore 350 (x2) OH/FL
Chrysler 350- Century Cheetah Mark II
Maintenance Log- I bought my boat (March 2014) with warranty replaced (3116) 3126TA engines. I received NO maintenance log but did have a diesel survey (incl fluid check). It has been almost 1 yr and just about up to snuff with maintenance. The best words of 'advise', the mechanicals are only as good as the human maintains them. We paid for 'professionals' to do maintenance and found so much was NOT 'done' (they never anticipated we would enter the engine room...no kidding!). My trusted friend and very knowledgeable 'mechanic' has now done SO much work. Had another 'survey' (since we have brought her up to a better 'level' of care) and went to work on a few more items. One of the most important 'lessons' for diesels...oil change...(we have an oil changing system)...make sure the oil is pumped out to where it runs 'clean'... must add a bit more (repeat process...out/in/out/in)...then pump out until 'clean oil' comes out. Immediately after our first oil change, the oil was still 'black' upon checking dip stick. So...assume it wasn't done ..or not well done..... had it changed again (by friend...and us present). Have run the engines 3 hrs and still the oil looks 'new'. The generator...appeared to have not had an oil change (original oil filter & painted over!!) nor impellers changed (bad bad shape)... I could list more BUT the bottom line...if there isn't a log...assume nothing has been done ....get it done. It has been an eye opening 'adventure' and we haven't even had much of a chance to cruise...yet. It is not the 'fault' of the engines...it is human prior neglect... 'Got beer, got ice, got fuel...let's go' (this is the 'moto' I hear from many boaters...). Heat exchangers...yep...addressed...transmissions...yep...addressed...and the list goes on....FIRE SUPPRESSION system (also neglected) now addressed.... she is now a 'beauty'...and 'safe'....and purrrrrssssss......
- Jun 2, 2008
- 5,024
- Boat Info
- 1998 450 Sundancer, Achilles dinghy w/15hp
- Engines
- 3126 Cat's
bad fuel solenoid relay
I too chased this issue for longer then I want to admit.... I have replaced both & numerous other parts I wont mention plus carry spares....
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
OK, here is a little more info on 3116 and 3126 Cat engines.
Both engines suffered from the installation of some soft valves from a vendor. The keepers would come loose as the valve stem wore allowing the valve to drop into a cylinder. This only happened when the engines was running producing power. This failure always occurred within the first 125-150 hours, so if you are looking at 15 year old engines with several hundred hours on them, they are free from this defect.
The other big problem people like to talk about are "soft blocks". This defect happened on a few 3126 blocks cast in a French foundry. The metallurgy was substandard (soft) so the engines tended to wear prematurely. Caterpillar tells us that there were no 3116's, only 3126's involved and that they replaced all the soft blocks they could find. Cat stopped warrantying this defect in about 2004. There is a simple inexpensive test any Caterpillar servicing deal can do on engines to rule out soft blocks. Just request a "Blow-By Test". The technician doing the survey will connect a manometer to the engine crankcase to measure the combustion pressures escaping past the piston rings. Cat has standards for blow-by so the test will quickly identify a problem engine.
Both of these problems are now historical and hardly worth discussing since both occurred early in an engine's life.
At 10-15 years out, a prospective buyer needs to pay more attention to the actual condition of the engines in the boat he is considering rather than what problems may have occurred in this type of engine somewhere in the past. In doing that, an engine survey by a Caterpillar technician is the starting point. Be sure to look at t hese points:
1. Try to reconstruct the service history.
2. Do fluid analyses on lube oil and coolant in the Caterpillars and in the generator......as well as the transmission oil, a total of 8 samples
3. look for excessive wear metals as well as foreign matter like silica (dirt/sand) or sodium (salt water)
4. Look for glycohol in the lube oil samples.
5. check temperature readings at both ends of the heat exchanger to verify heat transfer and make a guess at the condition of the heat exchanger
6. pull the inlet hose off the transmission oil cooler and look for debris
7. pull the basket out of the sea strainers and check for sand/dirt trapped in the strainer
8. Run the engines under load an observe the real operating temperatures. These engines will have 180˚ or 194˚thermostats in them. The temps should level off after the engines are fully warmed to operating temperatures. The temps should not keep rising. If they do there is inadequate heat transfer and the cooling system should be diagnosed.
9. Under normal loads, both 3116's and 3126's should run up to 2800 rpm at WOT; if they will not hit 2800, the bottom, props or running gear are fouled or the props are carrying too much pitch. Either indicate an overload condition for the engines.
In reconstructing the service history, look for annual oil changes, look for Cat brand OEM filters.....they are better and cheaper than aftermarket filters from NAPA, Fram, Baldwin, WIX etc., so there is no valid reason to avoid using Cat parts. The key service item is resetting the valves and injectors at 250 hours then at 1500 hours to 2000 hours, thereafter. As Pete said above, if you can't verify it, you need to redo it. This tends to increase the total cost of buying a boat because some of these service items can add up to significant money. The truth of the matter is that any of us who properly maintain these engines spend all this money anyway.....we just do it a little bit at a time.
My personal experience and that of others around me in our marina have had many years of excellent cost effective service out of our Cat 3116's and 3126's. Most of us have 1200 to 1800 hours and the most significant repair has been an alternator or a leaky injector seat. What you can look forward to is easy starting, smoke free operation, big torque/easy handling boats, maintenance so easy that an average owner can do his own, and very economical operation. Bullet proof is not a term I like to use, but the problems you hear about on these engines all seem to stem from abuse due to years of overloading, over heating or from neglect.
I think your real challenge will be finding the best boat you can, not anything to do with Cat 3116's or 3126's.
Both engines suffered from the installation of some soft valves from a vendor. The keepers would come loose as the valve stem wore allowing the valve to drop into a cylinder. This only happened when the engines was running producing power. This failure always occurred within the first 125-150 hours, so if you are looking at 15 year old engines with several hundred hours on them, they are free from this defect.
The other big problem people like to talk about are "soft blocks". This defect happened on a few 3126 blocks cast in a French foundry. The metallurgy was substandard (soft) so the engines tended to wear prematurely. Caterpillar tells us that there were no 3116's, only 3126's involved and that they replaced all the soft blocks they could find. Cat stopped warrantying this defect in about 2004. There is a simple inexpensive test any Caterpillar servicing deal can do on engines to rule out soft blocks. Just request a "Blow-By Test". The technician doing the survey will connect a manometer to the engine crankcase to measure the combustion pressures escaping past the piston rings. Cat has standards for blow-by so the test will quickly identify a problem engine.
Both of these problems are now historical and hardly worth discussing since both occurred early in an engine's life.
At 10-15 years out, a prospective buyer needs to pay more attention to the actual condition of the engines in the boat he is considering rather than what problems may have occurred in this type of engine somewhere in the past. In doing that, an engine survey by a Caterpillar technician is the starting point. Be sure to look at t hese points:
1. Try to reconstruct the service history.
2. Do fluid analyses on lube oil and coolant in the Caterpillars and in the generator......as well as the transmission oil, a total of 8 samples
3. look for excessive wear metals as well as foreign matter like silica (dirt/sand) or sodium (salt water)
4. Look for glycohol in the lube oil samples.
5. check temperature readings at both ends of the heat exchanger to verify heat transfer and make a guess at the condition of the heat exchanger
6. pull the inlet hose off the transmission oil cooler and look for debris
7. pull the basket out of the sea strainers and check for sand/dirt trapped in the strainer
8. Run the engines under load an observe the real operating temperatures. These engines will have 180˚ or 194˚thermostats in them. The temps should level off after the engines are fully warmed to operating temperatures. The temps should not keep rising. If they do there is inadequate heat transfer and the cooling system should be diagnosed.
9. Under normal loads, both 3116's and 3126's should run up to 2800 rpm at WOT; if they will not hit 2800, the bottom, props or running gear are fouled or the props are carrying too much pitch. Either indicate an overload condition for the engines.
In reconstructing the service history, look for annual oil changes, look for Cat brand OEM filters.....they are better and cheaper than aftermarket filters from NAPA, Fram, Baldwin, WIX etc., so there is no valid reason to avoid using Cat parts. The key service item is resetting the valves and injectors at 250 hours then at 1500 hours to 2000 hours, thereafter. As Pete said above, if you can't verify it, you need to redo it. This tends to increase the total cost of buying a boat because some of these service items can add up to significant money. The truth of the matter is that any of us who properly maintain these engines spend all this money anyway.....we just do it a little bit at a time.
My personal experience and that of others around me in our marina have had many years of excellent cost effective service out of our Cat 3116's and 3126's. Most of us have 1200 to 1800 hours and the most significant repair has been an alternator or a leaky injector seat. What you can look forward to is easy starting, smoke free operation, big torque/easy handling boats, maintenance so easy that an average owner can do his own, and very economical operation. Bullet proof is not a term I like to use, but the problems you hear about on these engines all seem to stem from abuse due to years of overloading, over heating or from neglect.
I think your real challenge will be finding the best boat you can, not anything to do with Cat 3116's or 3126's.
endless seas
Well-Known Member
1300 hours on our 97 450 with 3126. I have put 400 hours since purchased 8 seasons ago with Cat specified maintenance . So far with Franks guidance and an occasional Sunday phone call on my part he has saved me hundreds if not thousands of $$$.
The boat is very fuel efficient and a pleasure to own.
Good luck,
Tom
The boat is very fuel efficient and a pleasure to own.
Good luck,
Tom
FastMarkA
Active Member
I'm at 1300 hours (got it at 250 hours) on 3126TAs and with the exception of an impeller failure on a trip (which was a straightforward fix), these engines have been extremely reliable (they are serviced by Cat regularly).
The power is more than I could want and the fuel economy is impressive (these burn around the same as 2010-2015 models!).
The power is more than I could want and the fuel economy is impressive (these burn around the same as 2010-2015 models!).
