Bukh DV20 oil change. SAE30 ? plus how to drain the sludge

joyfull said:
Found major oil leaking around the oil filter. Seal does not seem to be working. The metal all feels rusty around where the gasket fits. Is there a solution by sanding around to smooth?
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It is very unusual for oil filter gasket faces to be corroded for obvious reasons. However, if it really is corroded and you have good access then sanding it smooth will resolve the problem. However, you need to be careful not to take to much metal off and leave a distorted surface as that might also be prone to leaking.

If the filter housing is bolted to the crankcase it might be better to remove it so you can get good access. If you can dismantle it and rub it onto sandpaper on a glass sheet so it is perfectly clean and flat, that would be the best solution.

Richard
 
On the sump plug, yes it is as you described.

The gearbox dipstick is a straight pull. It has a couple of o rings which I suppose could be sticking.

I don't think the oil filter mounting is readily removable.. is the seal facing actually rusty or just some crud, maybe the remains of an old seal? I'd try gently scraping it first in case you can get the crud, if that's what it is, to ping off.

If access is difficult remember you can use a mobile phone to take pics of what you can't see. It sometimes helps...
 
James_Calvert said:
On the sump plug, yes it is as you described.

The gearbox dipstick is a straight pull. It has a couple of o rings which I suppose could be sticking.

I don't think the oil filter mounting is readily removable.. is the seal facing actually rusty or just some crud, maybe the remains of an old seal? I'd try gently scraping it first in case you can get the crud, if that's what it is, to ping off.

If access is difficult remember you can use a mobile phone to take pics of what you can't see. It sometimes helps...
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I should think your suggestion of the roughness around the oil filter seating being the remains of an old filter seal is most likely. And worrying, since it suggests a poorly-maintained engine.

The OP needs to get a mirror in there with a good light and see what it is .
 
joyfull said:
I need an oil change on old DV20. I looked on Ebay and the SAE30 is listed as lawnmower oil. Would that be ok and how many litres for engine and gearbox.

I bought a pela 6000 to extract the oil and I read somewhere that if used down the filler cap it will not get to the bottom sludge. Is there some way of getting a good clean out as the engine is in a Centaur and so the drain plug is probably inaccessible.

The Bukh supplied brass oil extractor pump has sadly seized and broken off! Not sure where it was fixed to the engine and whether I can use that pipe as access point for the Pela.

This is the Ebay oil
OUR SAE 30 HORTICULTURAL OIL IS A PREMIUM QUALITY MONOGRADE LUBRICANT. IT IS DESIGNED TO MEET THE REQUIREMENTS OF A WIDE RANGE OF 4-STROKE ENGINES FITTED TO LAWNMOWERS, RIDE-ON MOWERS, TILLERS, CULTIVATORS, WACKER PLATES, PRESSURE WASHERS, GENERATORS, WATER PUMPS, BRUSH CUTTERS AND SOME STATIONARY ENGINES.

PERFORMANCE LEVELS: API CD/SD, CCMC D1,

MIL-L-2104B, MIL-L-46152B
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I only know what it lists in the Bukh 24 users manual table for different temperature ranges. The best all round oil seems to be Mobil 1 0w40, it does list 2 other types of Mobil 5w40 oils including Delvac, BUT both are very difficult to find.

Using a straight 30 grade oil is going to be bad news for cold starts, and SAE 30 is rather low for a hot summer. The only plus point about single grade oils is that they list slightly longer and a cheaper. The reason for that is that they do not include viscosity inhibitors which have a slight negative effect in high temp sheaing terms.

For a real old badly worn leaking donkey, I would ignore the chart and use Mobil 10w60, (It's more of a 50 in reality cos it's at the bottom of the 60 group), the EL rather than race version of that oil is Acea B4 compliant and contains high levels of detegents and Zinc based additives, in addition to seal conditions that are good for old engines.
If you change oil every 100, change the oil filter every 200 hours, as clean oil oil filters are far less efficient than dirty ones, although I would not use one for more than 2 years, as the limiting factor is the oil filter seal.

The Pela pump work, but so does fixing the original built in pump, and Ebay is a good place to buy oil, but make 100% sure it is one listed by Bukh. Second choice would be Shell Ultra 0 or 5w40 (A3/B4), BUT be careful as most companies do make C3 versions for old DPF diesels and those oils lack enough Zinc additives.

Last comment, there are marine engine oils that are listed by Bukh that are SAE 30 grades, BUT they have very restricted operating ranges in temperature temps. For a new diesel SAE 30 is often OK, but defintely not for an older donkey, as it will make cold starts difficult and increase the drip rate when hot.
 
peter gibbs said:
Love Bukhs. totally reliable and so DIY accessible. Run for ever.
Keep off the sump oil plug if access is difficult. Use the Pela.
Engine anode melts away fast - bet there's nothing much on yours. Replace for sure.
Difficult to start? Squirt a little oil in the air intake
Do check value clearances - easy to remove top cover.
Gear oil - trying to recall if it's one system all through, if so no need to pry gear box open. Check it out.

PWG
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If it does not start well, check all the glow plugs work, (Should measure 1 to 2 ohms only), then make sure the battery connections and battery state is OK.

I'm installing a Bukh in a few weeks time and planning on using a heater exchanger flush unit with a y valve to the water tanks to flush out the salt water. That way the anode and seals last far longer. Also adding soluble oil to the coolant reduces corrosion, BUT it's very dificult to find for some reason.
 
If you look up the efficiency a a normal paper oil filter it will list about 97% when new, (At 20 microns), and 99.5% when it is almost full. The full figure is based on the pressure differential across the filter and is fairly close to the point where the oil filter bypass valve opens. Spin on filters have those built in, and old style canister change jobs use a pressure relief valve that is in the engine itself.
So a lot of folks think there is very little difference between the 2 figures, BUT they fail to understand that it is the debris that gets past the filter that counts. So the new filter let past 3%, BUT the dirty one lets past only 0.5% of the all important 20 micron particles. So the dirty filter is 6 times more efficient. Exactly the same game and figures for air filters.
Yeabut some might shout, what about ultra modern glass fiber mat elements that have a very random hole size ? Very different story, cos they stop small particles just as well when clean as dirty, so no difference in the bypass or efficiency figures.
Not sure what other engines are using the same type of oil filters as BUKH, but there are a few companies that make synthetic oil and air filters for non OEM use.

Now for the other big mistake in engine wear and economic terms, and that is changing the oil too often. Changing the oil more frequently does help remove sludge if you use a recommended oil with a high detergent content, (The oils on Bukh's list are mostly high detegent oils), and is defintely a good idea if you suspect a leaking head gasket, BUT it causes a big increase in wear rates. that's exactly the opposite of what 99% of boat or car owners think.
The reason why changing the oil too often relates mostly to the fact that most engine oils contain detegents and Zinc based aadditives that act in a rather odd way at first. The detergents are too active and remove some of the anti wear additives, (Mostly Boron nitride, Zinc and Moly based), far faster than the new layer of Zinc is baked on. The net result is very high wear rates for about the first 30 hours of a 100 hour OCI. The problem is made worse to some extent by the fact that cheap non synthetic oils might look clean, but they are not, they contain high levels of 20 micron size particles that get stuck in the bearing races and in the rings or valve guide oil seals.

Ultimately the only way to find the best oil and filter, and to figure out when to change them is to take a small sample of used oil and send it to a lab, (I use Blackstones in the US), then wait for their experts to email or text the results. A few experiments will soon reveal the best oil change interval and let you know if the air filter is functioning, or the head gasket leaking. Even bad injector tips or pump seals can be detected with a high fuel contamination figure.
If I'm not doing oil analysis, I always sniff the oil, cos although a low viscosity can be detected by rubbing, actual diesel fuel contamination can be detected by sniffing at 5% plus. Alas 2% is the long term max figure.
 
There is only one reason that oil is frequently changed on older marine engines such as the Bukh Volvo MD series and even Beta and Nanni . All these engines share the same design feature regarding the type of fuel injection pump and where it is fitted.

Fuel pumps and injectors all exhibit an amount of leakage last the needles or plungers. In the case of the injectors this leakage (spill) is fed either back to the fuel tank or in the case of some Volvo marine engines back to a connection on the fuel inlet to the engine system. The leakage from the engine mounted fuel pump has only one place to go and that is into the oil sump. Over a period of time this diesel leakage results in fuel dilution of the crankcase oil which can in time result In various problems . We deal with this by changing the oil regularly..

I would certainly also Change the oil filter regularly rather than risk testing the efficiency of the bypass valve.. There are many suppliers of perfectly good filters, the hardest problem can be finding the correct one. Here in the UK many of the Motor Component companies have comparison lists which include marine engines. In Scotland I have found Dngbro to be able to offer various alternatives and they also stock such parts as starter solenoids at realistic prices. Dingbro and others share an enormous offshore drilling market where their products perform well in all types of machinery.

These Bukh engines were designed long before synthetic oils were produced and perform perfectly on standard multigrade oils. They enjoy no real benefit from the use of synthetic oils. I think any Bukh owner could waste a lot of time looking for glow plugs to test :) .

Oils such as this are perfectly satisfactory.

Marine10w-40 Classic Marine Oil
 
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Bilgediver said:
There is only one reason that oil is frequently changed on older marine engines such as the Bukh Volvo MD series and even Beta and Nanni . All these engines share the same design feature regarding the type of fuel injection pump and where it is fitted.

Fuel pumps and injectors all exhibit an amount of leakage last the needles or plungers. In the case of the injectors this leakage (spill) is fed either back to the fuel tank or in the case of some Volvo marine engines back to a connection on the fuel inlet to the engine system. The leakage from the engine mounted fuel pump has only one place to go and that is into the oil sump. Over a period of time this diesel leakage results in fuel dilution of the crankcase oil which can in time result In various problems . We deal with this by changing the oil regularly..

I would certainly also Change the oil filter regularly rather than risk testing the efficiency of the bypass valve.. There are many suppliers of perfectly good filters, the hardest problem can be finding the correct one. Here in the UK many of the Motor Component companies have comparison lists which include marine engines. In Scotland I have found Dngbro to be able to offer various alternatives and they also stock such parts as starter solenoids at realistic prices. Dingbro and others share an enormous offshore drilling market where their products perform well in all types of machinery.

These Bukh engines were designed long before synthetic oils were produced and perform perfectly on standard multigrade oils. They enjoy no real benefit from the use of synthetic oils. I think any Bukh owner could waste a lot of time looking for glow plugs to test :) .

Oils such as this are perfectly satisfactory.

Marine10w-40 Classic Marine Oil
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Marine 10w40 lacks the correct API classifications and is not even rated by the ACEA group as a B4 engine oil.

I wonder why they would not have that oil tested, it's probably lack of additives, which are as important as the base stock when the engine is cold started. Low detergent levels result in sludge building up in the sump, oil filter and intake screen to the oil pump in particular.

I really would stick to the major oil companies on Bukhs list, unless you send off a sample to get a VOA (Virgin Oil Analysis) done, which only cost about 20 quid. Then you can compare it with similar VOA results to see if its a bad base stock, or lacks the required levels of additives.

The Bukh approved engine oil list I have covers a variety of oils made by Mobil, BP, CALTEX, CASTROL, CHEVRON, ELF. EXXON, ESSO, NIPPON OIL, SHELL, STATOIL and TEXACO.

For some reason that list does not include Liqui Moly Synthoils, probably because they are too expensive. Their base stock is made by Fuchs and is a real class act in terms of how clean it is and how tough it is. Liqui Moly are the world leaders in Synthoil and fuel additives, so it's a surprise to see them missing from the list.

Classic oils often lack detergents as they were designed for old engines where fuel contamination and very short oil change intervals kept the engine blocks fairly clean. The benefit from group 4 and group 3 GTL (Gas To Liquids) technology oils, (Shell Ultra 5w40 ), applies to any type of engine and is well known to anyone that does used oil analysis in an attempt to extend the life of an old engine.

Not sure how long Bukh glow plugs last, but they are easy to test and cheap to replace, unless they use some special thread like Porsche metric fine.

One point mentioned was fuel contamination, which is a common issue if you do not run high power settings on occasions, as diesel fuel burns or evapourates off from engine oil if the oil temperature exceeds 50C, unless it's Bio diesel then it needs to be 80C. I've seen UOA results from diesels showing over 10% due to bad injector tips or old DPF systems. You can hear the difference when you listen to the engine with that type of contaminated oil, as it will start to rattle.

Last point is that if you are forced into using an unapproved oil, try adding a top of the range oil additive, (Unless under warranty), like Liqui Moly Ceratec. That expensive oil additive contains Moly, (Might not be needed), and a hexagonal form of ultra fine Boron Nitride in suspension. Bn is in some of the better oils in a cheaper less effective form, but it is very effective as an upper cylinder lubricant, as it deposits a fine film on the cylider walls and top end bearings. I would never add any other additive apart from a Castrol sludge flush oil that is only used at idle for a short while, unless you have talked to a real good Bukh dealer. Even fuel additives can be bad news, Biocides in particular can damage an injection pump if the engine oil lacks Moly in particular.

The solution to diesel bug is not additives, it's fuel and tank polishing or cleaning. It also helps to avoid high Suplur diesel, which is very common overseas in particular, as the Sulphur in the oil will form Sulphuric acid if the cyliders are not hot enough, so try to avoid idling when using cheap fuel. The other fuel issue apart from water contamination, is that some fuel companies add a little industrial alcohol to reduce diesel bug issue in storage tanks. That dodgy fuel can cause preignition issues at high power settings. Premature detonation inside the cylinders is a real head gasket killer, and can also damage the valve guide oil seals, glow plus and even the injection pump. Only thing that you can do is keep below max continous power.
 
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vyv_cox said:
I would not use any oil with viscosity less than 15w-40 in an elderly engine with copper-lead bearings and an unhardened crankshaft. These oils are fine on start up with aluminium tin bearings and hardened shafts but there is a big risk of bearing scuffing in old engines.
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15w40 oils are cheap to make, but they simply do not flow around the engine correctly when it is cold started, and that initial poor flow is very bad news if the oil also lacks the additional protection of Zinc based additives.

Bukh really do know what they are doing with their recommended oils list and if you read it, there are many 5w40 oils on the list, but only 2 0w40, Mobil Delvac and one of my favourites, Shell Ultra 0w40. Those 2 oils flow incredibly well at low temperatures, although a n 0w30 would be slightly better in some cases.

There are some good major brand oils recommended by Bukh, but if you look at the temperature figures, they really are for use during the summer or for engines with a heated engine room. If the oil is too cold when the engine is started the oil pressure soars up and the pressure relief valve then bypasses the oil filter until the oil warms up. Not good news either.

Oddly enough if you are chasing max main block life as I do, and need to operate in cold climates, an engine preheater system that warms up the oil is very effective at reducing cold start wear rates. You can fit heat pads on the sump of most engines, but you would need about 100W and the pads are normally 240v. It also takes several hours to warm up the oil.
Bukh diesels are designed to start in minus 40c as part of the Solas cerftification requirements, so their engines do not have any soft alloy bearings. To start in minus 40c, you would need to be using an 0w30 or 40 for sure.
 
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The area that the oil filter beds on to is machined but quite narrow. Get a good light in and have a look, should clean up easily. By the way to drain the oil I use a Lidl 12v oil pump. I’ve had mine years and it works much better than the Pela type.
 
TNLI said:
15w40 oils are cheap to make, but they simply do not flow around the engine correctly when it is cold started, and that initial poor flow is very bad news if the oil also lacks the additional protection of Zinc based additives.

Bukh really do know what they are doing with their recommended oils list and if you read it, there are many 5w40 oils on the list, but only 2 0w40, Mobil Delvac and one of my favourites, Shell Ultra 0w40. Those 2 oils flow incredibly well at low temperatures, although a n 0w30 would be slightly better in some cases.

There are some good major brand oils recommended by Bukh, but if you look at the temperature figures, they really are for use during the summer or for engines with a heated engine room. If the oil is too cold when the engine is started the oil pressure soars up and the pressure relief valve then bypasses the oil filter until the oil warms up. Not good news either.

Oddly enough if you are chasing max main block life as I do, and need to operate in cold climates, an engine preheater system that warms up the oil is very effective at reducing cold start wear rates. You can fit heat pads on the sump of most engines, but you would need about 100W and the pads are normally 240v. It also takes several hours to warm up the oil.
Bukh diesels are designed to start in minus 40c as part of the Solas cerftification requirements, so their engines do not have any soft alloy bearings. To start in minus 40c, you would need to be using an 0w30 or 40 for sure.
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I do not know the metallurgy of current Bukh engines but the question relates to older production engines that definitely use copper-lead bearings. Your advice is inappropriate for this query.
 
Main bearings nearly always contain Lead and Iron, Cooper is an interesting additive that is used in a variety of different bearings, mostly top end. It's not significant in oil analysis terms.

Back to what the OP posted:
This is the Ebay oil
OUR SAE 30 HORTICULTURAL OIL IS A PREMIUM QUALITY MONOGRADE LUBRICANT. IT IS DESIGNED TO MEET THE REQUIREMENTS OF A WIDE RANGE OF 4-STROKE ENGINES FITTED TO LAWNMOWERS, RIDE-ON MOWERS, TILLERS, CULTIVATORS, WACKER PLATES, PRESSURE WASHERS, GENERATORS, WATER PUMPS, BRUSH CUTTERS AND SOME STATIONARY ENGINES.
PERFORMANCE LEVELS: API CD/SD, CCMC D1,
MIL-L-2104B, MIL-L-46152B

Firstly, nothing wrong with buying oil from Fleabay, unless the cap is not sealed correctly.
SAE 30 monogrades are real tough oils, BUT they are no good for cold starts, a 5w30 is far better for winter time operations, unless its in the Artic when an 0w20 is the way to go.

The oil the OP is talking about is a poor quality one, because it could not get a n Acea B4 approval. The seller even admits this by not listing trucks, boats or even cars as applications. Mil specs are not used or listed by engine manufacturers, and the API folks do not check on oils used in the EU. It might still be a good oil, but the only way to know is to get a sample checked in an oil analysis lab.
 
TNLI said:
Main bearings nearly always contain Lead and Iron, Cooper is an interesting additive that is used in a variety of different bearings, mostly top end. It's not significant in oil analysis terms.

Back to what the OP posted:
This is the Ebay oil
OUR SAE 30 HORTICULTURAL OIL IS A PREMIUM QUALITY MONOGRADE LUBRICANT. IT IS DESIGNED TO MEET THE REQUIREMENTS OF A WIDE RANGE OF 4-STROKE ENGINES FITTED TO LAWNMOWERS, RIDE-ON MOWERS, TILLERS, CULTIVATORS, WACKER PLATES, PRESSURE WASHERS, GENERATORS, WATER PUMPS, BRUSH CUTTERS AND SOME STATIONARY ENGINES.
PERFORMANCE LEVELS: API CD/SD, CCMC D1,
MIL-L-2104B, MIL-L-46152B

Firstly, nothing wrong with buying oil from Fleabay, unless the cap is not sealed correctly.
SAE 30 monogrades are real tough oils, BUT they are no good for cold starts, a 5w30 is far better for winter time operations, unless its in the Artic when an 0w20 is the way to go.

The oil the OP is talking about is a poor quality one, because it could not get a n Acea B4 approval. The seller even admits this by not listing trucks, boats or even cars as applications. Mil specs are not used or listed by engine manufacturers, and the API folks do not check on oils used in the EU. It might still be a good oil, but the only way to know is to get a sample checked in an oil analysis lab.
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Not correct. The vast majority of diesel engine bearings are copper-lead, either cast or sintered, with either a lead-indium or lead-tin overlay. I have never heard of a lead-iron bearing, any references?
 
Rather nit picking, as my reply does say the bearings contain Copper and Lead in addition to Iron. Indium is not tested for by any of the cheaper oil labs, and Copper is not an easy one due to chemical reactions resulting in it not tracking engine oil hours, or even bearing condition.

This is why Caterpillar think Copper figures are not too useful in trying to determin if an oil is a good one:

Causes of Elevated Copper Levels Elevated copper levels occur when copper dissolves from the surface of the oil cooler tubes. The copper is in a solution with the oil and an insignificant amount of copper is removed from the oil cooler's tubes. After a period of time, a protective coating forms on the copper tubes and the reaction stops. The engine will not be damaged and the elevated copper levels will gradually decrease. For new engines, this reaction typically occurs within the first two oil change intervals. However, this reaction can also occur in used engines under the following circumstances:

This site is a good one if you are really interested in the use of Lead as a marker, as it is in the Journal bearings and is a real good indicator of trouble with the main bearings if it starts to trend up. Iron is the standard general wear indicator as it tracks engine hours. If either metals trend upwards, (Iron can be found on sump magnets), then it might be useful to increase the oils viscosity and use an oil high in anti wear additives. Best bet for a real bad old donkey is Mobil 1 10w60 EL (Extended Life), Acea B4 rated and an HC synthetic. HC synthetics are not quite as good as the real McCoy Synthoils from Liqui Moly, or GTL (Gas To Liquids) based oils like Shell Ulta, BUT it does not maater too much when an engine is starting to show a terminal trend which base stock it is, it's the higher viscosity and anti wear additives that can make a big difference. Liqui Moly Ceratec as a last resort should help.

What an Abnormal Oil Analysis Result May Indicate (machinerylubrication.com)
 
TNLI said:
Rather nit picking, as my reply does say the bearings contain Copper and Lead in addition to Iron. Indium is not tested for by any of the cheaper oil labs, and Copper is not an easy one due to chemical reactions resulting in it not tracking engine oil hours, or even bearing condition.

This is why Caterpillar think Copper figures are not too useful in trying to determin if an oil is a good one:

Causes of Elevated Copper Levels Elevated copper levels occur when copper dissolves from the surface of the oil cooler tubes. The copper is in a solution with the oil and an insignificant amount of copper is removed from the oil cooler's tubes. After a period of time, a protective coating forms on the copper tubes and the reaction stops. The engine will not be damaged and the elevated copper levels will gradually decrease. For new engines, this reaction typically occurs within the first two oil change intervals. However, this reaction can also occur in used engines under the following circumstances:

This site is a good one if you are really interested in the use of Lead as a marker, as it is in the Journal bearings and is a real good indicator of trouble with the main bearings if it starts to trend up. Iron is the standard general wear indicator as it tracks engine hours. If either metals trend upwards, (Iron can be found on sump magnets), then it might be useful to increase the oils viscosity and use an oil high in anti wear additives. Best bet for a real bad old donkey is Mobil 1 10w60 EL (Extended Life), Acea B4 rated and an HC synthetic. HC synthetics are not quite as good as the real McCoy Synthoils from Liqui Moly, or GTL (Gas To Liquids) based oils like Shell Ulta, BUT it does not maater too much when an engine is starting to show a terminal trend which base stock it is, it's the higher viscosity and anti wear additives that can make a big difference. Liqui Moly Ceratec as a last resort should help.

What an Abnormal Oil Analysis Result May Indicate (machinerylubrication.com)
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The lead is lost from copper-lead bearings preferentially as it is corroded by weak organic acids - the combustion products. The tin alloy overlay helps to prevent this but it is a very thin flash coat.

As I said, I have never come across an iron based plain bearing and understood that iron in oil analysis mostly derived from camshaft and follower wear. But that is not my speciality, whereas bearings is.
 
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