lubricating oil question

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saltyrob

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Hi Folks,

The manual for our Volvo 2002 recommends API CD quality oil. I understand that this has been superceded by API CF4 quality.I have read somewhere that you can cause additional wear an older diesel engine by using higher quality oil,ie, CG grades. However looking at a container of Volvo's own brand,(expensive) marine diesel oil, it is CG4 grade with no reference to other grades. Shell Rimula is CF4 and CG4,Cl4 together with other standards.So is it correct that higher grades will cause significant additional wear and will an will an oil which meets CF4 as well as higher standards be ok.I am probable over complicating matters but its raining hard here in Suffolk, so have been reading too much.

Many Thanks

Rob
 
Over the years, there has been a lot of discussion in these forums about oil quality, and some people have proposed the theory that modern, higher-quality oil somehow damages older engines. It's a theory that I can't understand or support - my view is that better quality oils are highly unlikely to cause damage. For my Volvo 2003T, I've used Halfords Part-Synthetic Diesel Oil (CF) for years, with no apparent ill effects.

Note that Rimula is only a brand name; there are many different types of Rimula oil, see here for a summary.
 
Interesting question. I am very fussy about the oil I put into my motorcycle, but have to say that I have generally gone for what is on the shop shelf when I do the oil on my 2002. I guess the rule for cars applies just as well to a marine engine in that it is the early days that lay down the parameters for longevity i.e. careful running in, scrupulous servicing etc. I consider it unnecessary to stick top dollar oil into an old engine, however I do think it important to stick to the service schedules, oil and filter changes etc. Marine diesels are pretty tough and can stand some awful abuse, but you do reap the reward of neglect at some time.
An innocent question, why is Volvo oil so expensive? I had to buy some from a Spanish boatyard and it was an eye-watering 50 Euros.
 
I use a generic - Halfords, Comma, etc 10-40 or 20-50 diesel in my 2003. I reckon anything else is a waste of money.

To my mind, religious changing of cheap oil is better than pushing the changes with a more expensive oil. The average sailing boat engine doesn't do enough hours in a season to get anywhere near needing a mid-season change, but a change at the end of the season means you get rid of a season's crud and the engine sits in nice clean oil during the winter. Recent turbo diesels may need a posh oil, but the 2002 is neither recent nor turbo, so don't waste your money!
 
What would you have paid for a generic oil?

SInce my car is carefully designed to make DIY servicing as difficult as possible and neither car nor boat use significant amounts, it's a couple of years since I bought any, so I don't know what current prices are, though I'll be finding out next weekend

Still, I agree that €10 or 15 isn't particularly significant when it comes to totting up the annual cost of owning a boat.* /forums/images/graemlins/tongue.gif

Of more concern is that read somewhere that synthetics can cause failure of oil seals in engines not designed for them, though this may be an urban myth.
(cue someone who actually knows what (s)he's talking about)





*I have a weak heart, so I never actually do this...
 
Modern synthetic and semi-synthetic oils are designed to work in relatively hot engines. Marine diesels, however, tend to run much cooler than car or indeed motorcycle engines and the clearances on the wearing surfaces also tend to be a bit higher. Many moden engines have coated cylinder liners (ceramic or precious metals) and these oils are designed to work with them.

Us a good quality mineral oil for diesels and all will be well. Prolonged use of synthetic and semi synthetic oils will tend to glaze cast iron cylinder bores, causing problems with the piston ring seal and interfering with heat transfer from the piston to the coolant.

Mineral oil is available from most motor factors, although I bought my last lot from an Agricultural Engineer.
 
I spent a while looking into this and ended up using the Quicksilver heavy duty diesel oil 15W/40 that most chandleries seem to stock at around £16 for 4l.
 
Good engine lubrication extends life, performance, reduces wear and fuel consumption (stating the obvious I know.)
I have been interested with engines for a few decades now, cars, motorcycles, lawnmowers, outboards and now marine diesels. Yes high performance, high rev-range, hot running engines with fine/narrow oil channels do need specialist oils (the obvious again.)
BUT! low reving, cool ish running, none turbo older style marine diesels do not. Stay with the manufacturers recommended viscosity rating plus add some Part-Co (other brands on the market) diesel oil additive (contains PTFE) then notice the reduced vibration and smoother running.
For the next stage we/I need the advice of some good chemical engineers because I cannot say what the results would be if diesel injector cleaner was added to the diesel fuel tank as well as a bio-bug additive. I have to admit that I have done this with no noticeable adverse reactions but as an option I would recommend the fuel filter/reservoir method where you replace all diesel from the filter reservoir then fill with the appropriate/correct injector additive, carefully replace filter with additive and run the engine.
This is not advice to bring life back to an engine which is beyond repair (although it could keep it on the edge for a lot longer) but to help all aspects of starting, running, performance and longevity.
 
I read a report that someone had run a car 200 000 miles on synthetic oil without changing it.
then they half drained it and ran another 10 000
then they drained it and ran 1000 miles
then they revved the guts out of it and manged to seize it.

Synthetic for me, if my engine dumps the oil in the bilges, I want it to get me home , in fact I don't even want to know there is a problem until I am back alongside.
 
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