Engine reliability

[nonitoo]

Perhaps a daft question but just how reliable should I expect my new Cummins Mercruiser 2.8L Diesel to be.

I only have one of them so it is quite important.

Does anyone have any experience of this engine ?

 

[Whitelighter]

Provided you service it correctly and do pre outing checks I would expect it to be 100% reliable

 

[peterb26]

Modern diesel engines are incredibly reliable and Cummins is a massive player in the diesel engine market worldwide, although not quite so big a player in the marine stakes.

Personally I switched from twins about 20 years ago. (Mainly to save money if I am honest as the running costs on my last twin were very high).

I have never had an engine miss a beat in that period (famous last words??). My new boat has a single D4-260 and I get 3 mpg at 16kts which isnt too bad in my opinion.

So you should expect your engine to be totally reliable, with a few caveats:-

a) If its brand new, then I would be a little cautious for the first 50 hours. Its not impossible for there to be a warranty claim, I have a minor water leak on this new boat - and on the last one I had a water leak and an oil leak! (Good old Volvo......) However these were sorted quickly and efficiently by the dealer.

b) The major cause of failure is dirty or water contaminated fuel. However, dodgy fuel stops twins just as quickly as it stops singles since I have yet to meet a boater who fills their twin tanks from separate supplies. (Im sure one exists though).
So check your fuel gravity filter visually very regularly - I do mine every trip as its easy to see on my boat.

c) Equally the environment for your engine is a harsh one. Every new boat I have owned has had 2 or 3 big tins of "WaxOyl" sprayed over the engine to help keep the dreaded corrosion at bay. Engine bays are not dusty - so there isnt really any drawback to this process in my opinion. (mind you it does make the top of the engine slippery if you walk on on!!)

d) Oil is the diesel engines life blood. Make sure that you adhere to the oil and filter changing schedule - although there is a growing tendency to say "50 hour changes" and I think thats over the top if I am honest.

e) Avoid running the engine in neutral for long periods. Get a battery charger if that is what you want to do. Modern diesels are designed to run under load and you do more damage running like this for 20 minutes than you do running under load for hours and hours.

d) Lastly, as you observe, you do only have a single engine - so be more vigilant before trips. Never leave the marina without checking all oil and water levels. Always visually check for any leaks as well. Test the tension of the belts too.

And of course, Enjoy!!

 

[nonitoo]

Thanks very much - I am reassured.

Yes, the engine is new and I am being careful during the running-in period.

BTW the engine is connected to a Bravo 3 outdrive.

I will make the checks you suggest (along with the requirements of the maintenance book).

 

[nonitoo]

One more thing (from reading your last post) I hope to use the boat for part of the time in the French canals and, of course this will be under light loads.

Do you think this will cause problems ?

 

[peterb26]

How light is the load? If its literally "tickover" then its not ideal. If its a few hundred above that then likely it will be ok.

 

[nonitoo]

Tickover is about 750 and I should think I will be mooching along at about 1200-1500 in the canals.

 

[peterb26]

I would have thought it will be fine.

 

[gibbowolfie]

Not trying to worry you but some engines suffer from oil starvation at one end of the engine if running at low load (but greater than tickover). It's worse if the boat is designed for planing and at displacement goes bows up. Can't comment on your particular engine/loading but though I should say. Unless it's a very new design I should think the dealer or manufacturer should be able to tell you.

If waiting at a lock for longer than 10mins I'd switch off, saves fuel anyways

Dead jealous of the thought of pootling on the French canals right now as sitting at a desk staring at a PC and my boat is out of the water /forums/images/graemlins/frown.gif

 

[nonitoo]

It looks as though I will be OK. At 1200 I am doing 4 kts and there is minimal bows-up attitude.

Thanks again for the advice.

 

[davedpc]

I think you should check if they rec. a torque down of the head after 100 hours.

 

[PCUK]

Cummins are legendary for their reliability and are also the cheapest genuine marine engine to service. All engine marine parts are available from your local truck dealer - some will need ordering but all are available at truck prices!!!

 

[nonitoo]

Wow ! Thanks for that - just hope I don't need many.

I'll check the torque but under the warranty the engine should be serviced by Cummins/Mercruiser after 100 hours anyway and this should be checked then.