Opinions on Cummins Quantum?

[maineman]

Anybody with strong opinions on a Cummins Quantum Series 5.9M3?
It's a 2006 with 3200 hours.
Thanks for any guidance.

 

[O C Diver]

Which HP rating? As the HP increases, there is more potential stress and wear on the engine. How the previous owner used and maintained it will likely be a bigger factor. Depending on HP and operating RPM, the engine could be pretty worn or at less than half life. Are there service records and oil analysis over several oil changes?

Ted

 

[DavidM]

In general the Cummins QSB5.9 is a great engine, but follow OC Diver's advice above. It is an electronic controlled common rail injected engine like most current models. It will run quieter with less smoke than mechanical engines, but it is subject to its electronics getting fried in a lightning strike.


David

 

[firehoser75]

Good advice so far. A lot depends on the maintenance and how the engine was run (used) by previous owners. Was the engine regularly overloaded, and run often at the maximum recommended rpm or higher? Is the engine aftercooled and if so have the aftercoolers been regularly serviced properly (if not it (aftercooler) may be shot). Is it a saltwater boat and if so how has "marine age" affected the engine (nothing to do with engine hours)?
Check out Tony Athens' website sbmar.com as he is highly regarded especially for Cummins engines. He offers a free forum and a huge amount of free info. Under Tony's Tips read about "marine age" for sure. If you want an opinion about that exact engine, join his free forum and post lots of good photos showing all angles of the engine and ER, and supply him with detailed info about the engine including serial number. Then he will be able to give you a pretty good idea about the overall general condition of that engine or answer specific questions.

 

[C lectric]

I will second Tony Athen's site as a huge bonus to any that will go look at it.
He has offered a HUGE amount of info specific to the Cummins engines
BUT
that can be used for any engine for free other than the time it take to read.


www.sbmar.com

 

[Ski in NC]

All QSB's are sea water aftercooled. So the coolers need to be maintained. We were spooked by all the electronics running these things, but they have proved remarkably reliable. Yes, lightning strikes, or even nearby, can kill them. Also they don't like high humidity engine spaces, but in that sense, no engine does.

Can't beat how social they are regarding noise and smoke. I like the 380hp and below, but even the ones above that rating have proven way more solid than us gear-heads expected.

If it checks out well and was reasonably maintained, I would not be afraid of high hours.

 

[maineman]

Thank you all so much. Your knowledge and expertise helps immensely.
I'll be pouring over Tony Athen's site this weekend.

 

[Baker]

Yep...I think the best advice here is how it was run. If it is in a slow boat, then very likely it has lots of life left in it. If it is in a planing boat and they ran it up on plane all the time, then it still might have life left but I would look a little closer if that is the case.

What kind of boat and what horsepower rating is it?

 

[rslifkin]

And even within planing boats, it'll depend on how it was run. If it was run at 180 or 200 hp output constantly up on plane, that'll give a much longer life than if it was putting out 300 hp for hours on end.

 

[bayview]

I think that some newer electronic controlled engines can display load duty cycle history information.

 

[Baker]

I think that some newer electronic controlled engines can display load duty cycle history information.

They can. But can they display any history? That would be interesting.