Oil - to change or not to change?

[Latestarter1]

I don't know what engine this came from, what oil was used or when it was previously changed
but I wiould be horrified if my filter looked like that

If you worked on buses or for that matter fire appliances which are going the same way, you would not be the least bit surprised.

Bus companies have maintenance overseen by finance people who dictate changing lubes as infrequently as possible.

Ask Tinkicker about the way they change the lube oil when the rare event happens..Some bus garages simply unscrew the lube filter and run the engine to pump the lube oil out into a drum. Adjusting the valves is done in a trice, go to stores draw new rocker cover gaskets, fit them and endorse records as valves adjusted, job done.

Abuse is sooo simple

 

[Bobobolinsky]

Why not take a sample and speak to http://www.millersoils.co.uk/ or http://www.morrislubricants.co.uk/scripts/default.asp

Both used to offer a sample testing service to tell you what the oil was like. Going back a few years but might be worth a call .

Naw change the oil. Tight, or loose bearings breakdown the long chain molecules of the oil, gradually reducing the lubricity of the oil, moisture emulsifies the oil and fuels cause deposits of acid in the oil. Lots of reasons to change the oil. Testing the oils is more expensive than a change.

 

[Bobobolinsky]

My 60+ year old engine (and hydraulic transmission) demands the most basic SAE30. £7 bloody 99 per litre HTF does that work?

WOCO

http://www.withamgroup.co.uk/default.asp?page=354

Minster monograde Lincoln isn't too far

Do epoxies, polys and antifouls

 

[Hostage]

Oh fighting talk there...... FYI Bukh recommend a straight sae30 lube oil for both the engine and gearbox on my "vintage" DV24 and that is what they get (the engine and gearbox) - no multi grades, no synthetic oils (either semi or full) and no EP gear oils or ATF. - 5 litre sae30 is around £15 or if I buy a 25l drum it is around £60. I think I prefer to follow the guidance of the engine manufacturer rather than some rabid ramblings on a forum.

For my money £20 once a season for an oil change is a lot better deal than the same money will get you in a marina.

 

[CAPTAIN FANTASTIC]

Oil gets contaminated with carbon and fuel and therefore it looses its designed abilities; old oil will actually grind metals.

Change oil as frequently as possible ie approx every 5,000 miles or equivalent in hours

 

[Avocet]

Oh fighting talk there...... FYI Bukh recommend a straight sae30 lube oil for both the engine and gearbox on my "vintage" DV24 and that is what they get (the engine and gearbox) - no multi grades, no synthetic oils (either semi or full) and no EP gear oils or ATF. - 5 litre sae30 is around £15 or if I buy a 25l drum it is around £60. I think I prefer to follow the guidance of the engine manufacturer rather than some rabid ramblings on a forum.

That's what was recommended for my old BMW D12, but I've never used it because I couldn't be bothered sourcing it. What we don't know is whether (if such an engine were designed tomorrow) they would still recommend a monograde mineral oil.

 

[Avocet]

You mention VW.
They shout loudly about their "longlife" service regime - sophisticated engineering, special lubricants etc., OK for "up to" 2 years or 20k miles.
However when you read the small print, this is only if you do at least 25 miles every time you use it and do mostly steady speed work like motorways.
If you do short journeys and urban type use - it's back to 12 months/10k miles.
So which regime would you put the typical yacht engine on?

My company SEAT was on "longlife" from new and didn't ask for an oil change until 19,000 miles. I do plenty of sub-25 mile runs (supplemented by a lot of motorway work too). A total of about 25,000 miles a year. On average, I'd say 70% of my journeys were sub-25 miles, but the remaining 30% are very long.

 

[Plevier]

My company SEAT was on "longlife" from new and didn't ask for an oil change until 19,000 miles. I do plenty of sub-25 mile runs (supplemented by a lot of motorway work too). A total of about 25,000 miles a year. On average, I'd say 70% of my journeys were sub-25 miles, but the remaining 30% are very long.

I think it really means 25 miles from a cold start so several short trips in quick succession would qualify.
I know there is a sensor in the sump but I don't know what it measures. Conductivity maybe?
Also I don't know what is different about the longlife oil (other than £££). Lots of detergents and dispersants maybe?
I'm a traditionalist, I don't like the idea anyway!

 

[Spyro]

Not a good idea. No matter how hard you try you will not get the last bit of sludge out of the sump

How else would you get the oil out of a yanmar 2gm20 with no sump plug?

 

[Marsupial]

Marine engines and oil changes will be a subject much discussion for well into the next century. The engine may well be made to finer tolerances then say 20 years ago but the fact remains that acids, carbon and moisture will build up in the oil regardless of the pedigree and regardless of the oil. Its a tribute to modern designers that they get engines to perform at all given the environmental issues they have to design to.

The problem is further compounded in the antiseptic EU with the result that very few engines are true marine engines - in other words can be operated and maintained anywhere in the world. Instead they need special oils and if not right now then very soon special fuels; the nightmare begins.

However when all is said and done if you need to question whether its a good idea to change engine oil in a marine environment and don't because some bloke down the pub has boasted his complete lack of knowledge and not changed his, then you demonstrate a a fundamental lack of understanding about things mechanical, your engine WILL fail you. Your only saving grace is that modern engines are well made and will put up with abuse for some time but while they are seeming to be running OK they will be wearing out at an alarming rate.

The rule is that engines don't fail because the oil is clean, but they will fail if its not. Its a certainty, failure is guaranteed its not a myth.

Manufacturers know this but are under extreme pressure from governments to reduce oil dependency and customers to reduce service costs; they do a complicated sum around what a typical owners expectation is and how cheaply that expectation can be realised.

If the engine will last long enough for the first buyer to recommend the thing and buy another that is all they have to satisfy. If that means that a 100,000 hour engine has its life reduced to 10,000 hours then why not? extending its life to its full potential will cost money and not actually enhance future sales - so they don't do it.

I would agree that changing oil filters is a questionable activity IF the oil is changed regularly; so if you want to save some money change the oil and change the filter every other service.

Have a nice day

 

[angelsson]

This sounds like madness, but what do the wise-ones think?
Regular oil changes essential, or just a con wasting our money/time?

I was talking with a good friend recently who has owned all sorts of top-end cars. He (like most/all of us) had his BMWs etc regularly serviced and paid painfully for the work and materials.
But he says for three years (approx 50,000 miles) he has not changed the oil in his Trouper 4x4 or his wife's VW Touran. He claims the need for oil changes is a myth foisted on us all by the motor/engine industries. His decision is not money-driven.

Granted in engines of yesteryear when tolerances were worse than the precision stuff we now have there would be more "bits" in the oil, but could modern precision machining prevent all wear?

If motives not money-driven then why take the risk of expensive repairs?

As to 'yesteryear tolerances' they were in many ways better, + or - 1/10,000 of inch was common practice and engineering built to last.

 

[Avocet]

I think it really means 25 miles from a cold start so several short trips in quick succession would qualify.
I know there is a sensor in the sump but I don't know what it measures. Conductivity maybe?
Also I don't know what is different about the longlife oil (other than £££). Lots of detergents and dispersants maybe?
I'm a traditionalist, I don't like the idea anyway!

Mine still does plenty of those! I'll be doing the school run (3 miles) later today, from cold! I do that most days. The total cumulative mileage of "short runs" is small, of course, but there are more of them.

Not sure if the current VAG cars really do have a sensor for oil quality. I know some are just an algorithm based on driving style. Cheaper sensors are capacitive - just 2 plates and the oil is the dielectric between them. As it gets contaminated with crud, the capacitance changes in some way. There are better ones. Hella have a nice "tuning fork" jobbie, where the reeds of a thing a bit like a tiny tuning fork vibrate in the oil and it can (somehow!) derive density and viscosity from that (as well as measuring contaminant levels).

 

[tinkicker0]

No mention of marine engines in OP, so dunno where mention of yachty thumpers came from.
some confusion surrounding oil properties also.

Simple fact is older engines without a full flow oil filter usually require a low dispersing oil and more frequent changes as the oil will deposit the days contamination into the sump as sludge to be drained out at the next change.

More complex engines with full flow filter does require a higher dispersant oil to keep solids in suspension to be filtered out at source.
Note that there should be no sludge in the sump.
never confuse the two and always do your homework when choosing your oil.

 

[grumpygit]

Marine engines and oil changes will be a subject much discussion for well into the next century. The engine may well be made to finer tolerances then say 20 years ago but the fact remains that acids, carbon and moisture will build up in the oil regardless of the pedigree and regardless of the oil. Its a tribute to modern designers that they get engines to perform at all given the environmental issues they have to design to.

The problem is further compounded in the antiseptic EU with the result that very few engines are true marine engines - in other words can be operated and maintained anywhere in the world. Instead they need special oils and if not right now then very soon special fuels; the nightmare begins.

However when all is said and done if you need to question whether its a good idea to change engine oil in a marine environment and don't because some bloke down the pub has boasted his complete lack of knowledge and not changed his, then you demonstrate a a fundamental lack of understanding about things mechanical, your engine WILL fail you. Your only saving grace is that modern engines are well made and will put up with abuse for some time but while they are seeming to be running OK they will be wearing out at an alarming rate.

The rule is that engines don't fail because the oil is clean, but they will fail if its not. Its a certainty, failure is guaranteed its not a myth.

Manufacturers know this but are under extreme pressure from governments to reduce oil dependency and customers to reduce service costs; they do a complicated sum around what a typical owners expectation is and how cheaply that expectation can be realised.

If the engine will last long enough for the first buyer to recommend the thing and buy another that is all they have to satisfy. If that means that a 100,000 hour engine has its life reduced to 10,000 hours then why not? extending its life to its full potential will cost money and not actually enhance future sales - so they don't do it.

I would agree that changing oil filters is a questionable activity IF the oil is changed regularly; so if you want to save some money change the oil and change the filter every other service.

Have a nice day

I quite agree with Marsupial's comments. If I may just add some extra reasons for oil changes for engines in the marine environment.
Because of short running times on most sail boats (well we have flappy things and deep pockets) the engine never gets to a good operating temperature, and actually they nearly always run on the cool side at operating temperature, this in turn creates condensation which deposits into the sump and this contaminates the oil and leads to a breakdown of quality.
Another is the fuel and especially high sulphur fuels, this leaves corrosive acid deposits in the lube.
One should look at an oil change as a very cheap spanner, it will save heart break in the long run. If you lay up for winter the oil change is better to be done at the end of the season, this saves acidic and contaminated oil sat in the engine all over winter.

Standard filters are only brick stoppers at the end of the day but can and do deteriorate so for the small price they cost why not change them. Replacing them bi annually if the oil is changed annually may be feasible for the wallet watcher.

As for extended service times of the road vehicle and blatant disregard and boasts of some owners. For me it would be akin to a ticking time bomb!
I have seen many an engine destroyed because of lack of lube services. One of the main is the oil pump strainer blocking with debris and starving the engine of oil . . . . . . Bang!!

-------------------------

 

[lynall]

If you worked on buses or for that matter fire appliances which are going the same way, you would not be the least bit surprised.

Bus companies have maintenance overseen by finance people who dictate changing lubes as infrequently as possible.

Ask Tinkicker about the way they change the lube oil when the rare event happens..Some bus garages simply unscrew the lube filter and run the engine to pump the lube oil out into a drum. Adjusting the valves is done in a trice, go to stores draw new rocker cover gaskets, fit them and endorse records as valves adjusted, job done.

Abuse is sooo simple

I would love to be witness to an oil change the mess must be unreal!


Lynall

 

[Avocet]

No mention of marine engines in OP, so dunno where mention of yachty thumpers came from.
some confusion surrounding oil properties also.

Simple fact is older engines without a full flow oil filter usually require a low dispersing oil and more frequent changes as the oil will deposit the days contamination into the sump as sludge to be drained out at the next change.

More complex engines with full flow filter does require a higher dispersant oil to keep solids in suspension to be filtered out at source.
Note that there should be no sludge in the sump.
never confuse the two and always do your homework when choosing your oil.

That's interesting. Roughly when was the changeover? I mean, are we talking "pre-war" or last 20 years or...? Mine's a bit of an oddball - no filter, no oil pump, roller bearing crank (but plain bearing big end). I've nearly always just use a plain mineral diesel multigrade - tried that Castrol Magnatec semit-synthetic once though.

 

[Latestarter1]

I have read posts from Marsupial and grumpygit and whilst some of their logic is nuts I kind of agree with their sentiments.

Having actually designed diesel engines and formulated their operating peramiters, and represented UK members of ACEA against excesses of EU I cannot believe people make such hard work of maintaining marine diesel engines. Other posters waffling and making constant references to boutique automotive diesel engines which employ all manner of after treatment strategies of zero relevance to marine duty cycles and emissions. Talk of engines grinding with metal to metal contact, lube filters being referred as merely rock stoppers, this is all simply vapourware.

#1 No manufacturer is prepared to compromise engine life, just the opposite there is constant pressure to increase B50 and B100 (Industry durability/reliability standards).

#2 RTFM it is the Bible, not another owners opinions.

#3 Having read the manual just understand how lube oils work. Clean and fresh 15W40 lube to say ACEA E5/7 will have TBN (Total Base Number) of around 10. and TAN (Total Acid Number of 0. Combustion formas acids which gradually degrade the TBN. When TAN exceeds TBN lube has had it! The clever bit is to predict (dependant on duty cycle) the point at which the two graphs cross over. TBN depletion is a pretty linear curve whilst TAN is a scatter graph. Oil sampling which includes TBN Vs TAN result is expensive and often cheaper to simply change the lube oil. Also remember that topping up lube tops up the TBN, therefore lube will appear to last longer in an engine which has a 'drink' problem.

#4 Extended life filters are dangerous as they can actually damage the vital additive pack. Correct spec filters are not 'rock stoppers' they are critical components in the system.

Trust me when you are putting a contract spec together for horizontal 19 liter rail engine life to overhaul is your call, the operator only pays you for productive 'up time'. Rail engine duty cycles are evil, diesel engines love constant speed, they rarely see that in a DMU. Operator pays you for say 15/17,000 hours of productive time to overhaul. Lube service intervals are your call, too short and you do not get the contract, too long and engine fails to meet contract requirement and you lose your job. Understanding non linear TBN depletion is critical.

How do we get around all this horse manure in boats? We just change frequently, not forgetting the filter!

 

[Marsupial]

I have read posts from Marsupial and grumpygit and whilst some of their logic is nuts I kind of agree with their sentiments.

Having actually designed diesel engines and formulated their operating peramiters, and represented UK members of ACEA against excesses of EU I cannot believe people make such hard work of maintaining marine diesel engines. Other posters waffling and making constant references to boutique automotive diesel engines which employ all manner of after treatment strategies of zero relevance to marine duty cycles and emissions. Talk of engines grinding with metal to metal contact, lube filters being referred as merely rock stoppers, this is all simply vapourware.

#1 No manufacturer is prepared to compromise engine life, just the opposite there is constant pressure to increase B50 and B100 (Industry durability/reliability standards).

#2 RTFM it is the Bible, not another owners opinions.

#3 Having read the manual just understand how lube oils work. Clean and fresh 15W40 lube to say ACEA E5/7 will have TBN (Total Base Number) of around 10. and TAN (Total Acid Number of 0. Combustion formas acids which gradually degrade the TBN. When TAN exceeds TBN lube has had it! The clever bit is to predict (dependant on duty cycle) the point at which the two graphs cross over. TBN depletion is a pretty linear curve whilst TAN is a scatter graph. Oil sampling which includes TBN Vs TAN result is expensive and often cheaper to simply change the lube oil. Also remember that topping up lube tops up the TBN, therefore lube will appear to last longer in an engine which has a 'drink' problem.

#4 Extended life filters are dangerous as they can actually damage the vital additive pack. Correct spec filters are not 'rock stoppers' they are critical components in the system.

Trust me when you are putting a contract spec together for horizontal 19 liter rail engine life to overhaul is your call, the operator only pays you for productive 'up time'. Rail engine duty cycles are evil, diesel engines love constant speed, they rarely see that in a DMU. Operator pays you for say 15/17,000 hours of productive time to overhaul. Lube service intervals are your call, too short and you do not get the contract, too long and engine fails to meet contract requirement and you lose your job. Understanding non linear TBN depletion is critical.

How do we get around all this horse manure in boats? We just change frequently, not forgetting the filter!

I hope I am not that nuts there lots of engines out there with a lot of ME in them, if I am nuts god help them.

Total Acid Number TAN is a function of the fuel and the humidity of the air both are not variables that the engine can modify hence the problem with acid in marine engines; as you say change the oil its cheaper.

The filter thing - Change the oil often yes more often than the manufacturer recommends the filter when its reccomended, may I just remind you that most of our yacht engines run on straight grade oil with no additive pack or a very primitive one, I did lots of work on this when they were trying to extend oil change intervals on truck engines unless the duty cycle is very adverse filters don't catch very much, (cut a few up, or do the dry them out and weigh them thing after you have done a dozen or so you get to know what your looking at, most of the time its not very much) - but I ve seen loads like the one pictured above in normal servicing, (that is not when the manufacturer is logging every engine start every journey every oil level check) always wondered at how they managed to drive the thing in. If the additive pack has failed there is something else very wrong, its not the oil filter.

AND yes manufacturers do compromise engine life and reliability; sit through ANY engine related warranty meeting and all they are interested in is how little can they spend to get out of the smelly stuff. Their in the smelly stuff because they compromised on design and equipment in the first place but that argument is all too often lost on them. When we were making the things we would often say that bit is a going break/wear-out/cause a problem with that bit and break but we were silenced, then a few weeks later we were being asked if a modified whatsit could be made on the same machinery at no extra cost - dream on. OR an equipment supplier would say something like we told you this would be the outcome but you continue to insist on paying X for that part and its failing we cant help you unless you are willing to pay x+1.

Then I went to the service side of the business - looking after anything with an engine; it never ceased to amaze on how ingenious the end user could be and how determined they could be to wreck an engine and transmission.

back to the asylum

have a nice day

 

[Avocet]

All good stuff there, but getting back to the "RTFM issue", is that really always the best policy? The designers of an engine designed 40 years ago won't have had access to the lubricants of today. How do we know they're not going to be as good (if not better) than was originally specified? My manual has a handy chart in it telling you what (straight) grade of oil to use for a variety of ambient operating temperatures, but these days, a multigrade means I don't need to bother!

 

[vyv_cox]

All good stuff there, but getting back to the "RTFM issue", is that really always the best policy? The designers of an engine designed 40 years ago won't have had access to the lubricants of today. How do we know they're not going to be as good (if not better) than was originally specified? My manual has a handy chart in it telling you what (straight) grade of oil to use for a variety of ambient operating temperatures, but these days, a multigrade means I don't need to bother!

This question has been done to death in this forum, there is a page on it in my website, Engines>Oil for yacht engines.

Virtually every club, society, etc that runs old engines in cars, boats, tractors, etc agree that using modern high performance oils in them will accelerate their demise. For example, many canal boats use BMC 2.2 and 2.5 litre engines. Morris Lubricants make API CC oil, a grade that became obsolete in the 1950s, specifically for them and sell a lot.