Diesel engine lifetime

hectou

hectou

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20 Feb 2006
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Location
Sardinia until 04/08
www.saltwatergypsy.com
I'm sure this has been raised in the past but I can't track it in the Forum. How long should you expect a modern, well-maintained engine to last before a major overhaul is needed? I have variously seen 5,000 to 20,000 hours and commercial engines are expected to last 20years. Does anybody have an up to date figure?
A Good New Year to all!
 
I dont think you can put a standard figure on this. It depends so much on both how it has been used and how it has been maintained. A diesel engine on a yacht is hardly ever worn out by over-use, much more likely to become choked by scale and salt deposits. Quite often a prolonged period of use does it good rather than harm (e.g. motoring across to France).

A small lightweight engine will always fail before the larger heavier less stressed engine.

But it is the maintenance that is the most crucial factor.
 
Depends on installation, use and maintenance.
eg I expect to get 10,000 to 15,000 hours before needing to overhaul heads-change the oil etc on my engines at work with bottom end full strip down etc perhaps 80,000 hrs - these engines being typically 1,2000rpm 2.5MW size

My yacht engine ( Ford 1.6 XLD ) is 20 years old and has some 5,000 hours. I have not had to overhaul injectors etc for 10 years and oil is typically changed every 3/4 years. Otherwise I just feed it good fuel, and change the filters. not foregetting air inlet - a diet of salt is just a harmful as fuel contaminated with water. Iwould expect it to last at least another 10/20 years before bottom end overhaul with perhaps a couple of injector changes in that time.

However I must say IMHO looking at and having maintained small volvos in the past I do NOT rate this junk highly and would not expect them to last as long even with careful maintance.

Brian
 
Its no wonder the Volvos were junk if you changed the oil every 3/4 years /forums/images/graemlins/confused.gif. I also maintained small and large diesels and changed the engine oil AND filter reguraly winter and summer regardless of hours,i like volvos as they are proper marine diesels,they like all other engines only go wrong from bad maitainance or miss use.
 
Weight of engine in pounds divided by consumed HP, answer is in years.
Everything really depends on maintenance regime but the above introduces the big heavy versus lightweight modern issue.
I'd be surprised if a good diesel went less than 10,000 hours between major overhauls.
Too many answers to this question!
Happy New Year everyone.
 
Everyone to their own opinion.

In mine I totally agree good filtration is a must but if analysis says the oil is within specificaiton then its a waste of time, energy, resources and with work engines, shareholders profit to change it.
I would also add use correct specification fuel as well as careful maintenance and avoiding misuse such as excessive thermal cycling.
Working in the tropics in the 70s you could always tell where what makes of engine were where from the smoke - the Detroits and Cats where the best at coping with mucky fuel out of rusty drums in my exprience.


The small Volvos are not unreliable but have too many undesirable design features in commercial use for me which make keeping them going in far way places a pain compared with more simpler robust designs.
Add in the price of spares and give me a Ford etc any day, indeed if I was going blue water, a Volvo would not be in my ER period.
However if a cheap engine is wanted for use around the solent for 10 years with the idea of replacement rather than overhaul, then that is where they are best suited.

Brian
 
Agree with the" if the oil is in spec leave it,"but your average boaty doesnt have the kit to test the oil,and we are only talking a couple of litres anyway.so its a case of simple maths;
Oil and filter.. £25,
Engine replace,£lots.
I would also like to know the undesirable features of the Small volvo,to my mind the 2000 series are great little engines,spare parts can be obtained at reosonable prices from places online such as keypart,but if you follow a good maintance scedule they will last a very long time.
 
Commercial and leisure engine applications are equivalent to apples and oranges. An inappropriate comparison. They are required to do different jobs and hence have very differing requirements. Poor old Volvo seems to be cited as an example so why not take a more detailed look. Their 12 litre engine, for example, is rated about 450 bhp on the road (Truck & Construction Equipment). Marine versions vary from about 300 bhp (commercial duty cycle, run for ever) stretching to almost 700 bhp for leisure use. Many of the smaller Volvo are badged and painted green!

The best we can do for our engines is (i) keep them clean and free of leaks and so on. (ii) run them on clean, filtered fuel bought from a reputable source (but everyone has a few problems from time to time), (iii) change oil and filter regularly, at least once a year, (iv) clean or replace air filter, too, (v) try to get rid of salt deposits and run inhibitor as she is lifted, (vi) generally keep and eye on the effect of moisture on the electrical conections. (vii) ditto take care of drive belts. (viii) don't forget gearbox, shaft, seal, morse and so on. Now that it's winter, perfect time to read the manual check if any major service items are required before the new season?

The only other is consideration is a bit more fundamental. Don't forget to use it and have some fun on the water. It's true that diesels prefer to be worked harder.

No point being paranoid about life. They usually have a way of letting you know when something is wrong. If it's instant and catastrophic, it's equally likely to have happened at any time. If it's progressive, there's plenty of notice to get it fixed.

Hope this is helpful and unbiased (as it's meant to be!)

David
 
Nice list. Would you agree to the addition of this element? Or is it more of an old wives' tale?

If you're not going to use it for a couple of months or more, limit corrosion. Keep air out (bungs in the inlet and exhaust), change the oil, put some oil in the bores thru the injecter holes and turn over a couple of revs before replacing the injecters, flush all salt water out fo the primary system and replace with inhibitor laced water . . .
 
I've been taught to change the oil after 6 months or so, even if the engine has been lightly used, as used oil deteriorates with time, BUT:

oil in my car only gets changed every year! and

is there any point at all in changing the filter before its due number of engine hours specified by the maker (ie if the engine is used only for a small number of hours every year, does the filter really need changing every year)? ... unlike the oil, there seems to be no way it can deteriorate purely as a function of time
 
I didnt think i was being paranoid, /forums/images/graemlins/confused.gif when i was doing the diesel part of my apprentiship it was drummed into us bad oil kills engines,and for the sake of a few quid change the oil regualy.OK for big commercial engines test the oil as there is big mony involved in an oil change,but i thought we were talking small lesure diesels.
 
This is a really interesting discussion but soon falls outside the scope of routine maintenance and moves almost into the realms of a debate.

High pressure, temperature and byproducts of combustion all play their part to make oil more acidic. Acid attacks the engine. A fair amount of oil is lost through, for example, blowby, combustion and leakage but it's usually replaced by unburned fuel. After many hours, let's not put a number, a remarkably high percent of the sump can be made up of residual fuel.

For my boat, there is no difference between 6 months and one year albeit I prefer her to lie in fresh oil, not acidic oil for obvious reasons.

With low hours there is probably no real reason to change the filter. Firstly, I'm unlikely to cause damage by changing it and secondly, the cost of a filter is (relatively) small so for peace of mind I'd change it.

If I was leaving the engine mid season, everything you suggest, Jim, makes good sense except I would not remove the injectors. I strongly believe in this case that I'd risk more harm than good. Best to leave well alone here, IMHO.

To chris, sorry I didn't mean to imply paranoid in such a way, my poor choice of words, oops, sorry. I didn't introduce commercial engines into the thread, I tried to clearly differentiate away from them!
 
No probs, /forums/images/graemlins/smile.gifbut my initial reply was to brianhumber and his oil changing routines,these discusions can easily fly off on tangents which is the whole point of the forum i suppose.
 
To point to just three areas, things like injector pockets design, location of various fixings when trying to remove parts without lifting up the whole engine, general cold starting on a high hours engine.
None of them are show stoppers, or impossible to fix I freely admit , but other designs in my exprience are better in these areas.

Sadly I have not seen any air cooled engines on any yacht, but the best small engines for small open boats were the Listers and Petters, which were almost too good a design. They went on for years, very simple and easy to pull apart if you ever needed too and you could always get them started (even when frozen up in a Baltic Winter).

Brian
 
It seems we can agree that variety is the spice of life and forums then!

I am not so sure that there is much difference now between leisure and commercial offering these days and rebadging of engines, cars, vans etc seems to be the order of day.
Getting back to oil changes or not, as a matter of principal I just do not like changing or chucking anything with life left in it. Its why I keep my cars to over 200,000 miles, use a 1950s lawnmower and ride my mothers 1940s bike. Yes I am a tight bugger but perhaps the relentless increase in costs will make a few think along my lines as well as being 'greener'.
It has not on my engines be they car, boat or at work worn them out prematurely.

anyway good safe exciting boating for 2008 to all

Brian
 
[ QUOTE ]
If I was leaving the engine mid season, everything you suggest, Jim, makes good sense except I would not remove the injectors. I strongly believe in this case that I'd risk more harm than good. Best to leave well alone here, IMHO.

[/ QUOTE ] I accept your point here. Depends how long you're leaving the engine, and how simple the injector installation is. Don't disturb unless there's an obvious gain . . .
 
And what about the following sentences:
"If the boat is not going to be used for some time but is being left in the water, the engine must be run to operating temperature at least once every 14 days. This prevents corrosion in the engine"
Source: Volvo operator manual

It is sounds a little radical to me, but it is manufacture's recommended.
 
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