Cranking Over After Oil Change

[Dockhead]

I change my oil fairly frequently -- three or four times a year, so usually less than 100 hours.

On the theory that a diesel engine pukes a lot of nasty things into the lube oil -- soot, acids -- and will be much happier with clean oil. And it is so easy and cheap to do -- why not?

One thing which bothers me, however, is starting up after the oil change -- the engine running dry and making alarming noises for a few seconds. It can't be good for it!

I tried once cranking the engine over with the Stop button pressed -- and was rewarded with popped breakers.

What do you guys do?

[Astrid]

I generally don't worry about it. Start up is always the hardest time on an engine anyways. Assuming your oil change does not include a complete flush out of the oil system, you should have enough residual lubrication throughout the engine from warming the engine up prior to the oil change and from fresh oil as it was added to the engine following the change (at least on mine the filler cap is on top of the valve cover so oil pretty much drips down over everything on its way to the sump).

[GordMay]

Originally Posted by Astrid

I generally don't worry about it. Start up is always the hardest time on an engine anyways. Assuming your oil change does not include a complete flush out of the oil system, you should have enough residual lubrication throughout the engine from warming the engine up prior to the oil change and from fresh oil as it was added to the engine following the change (at least on mine the filler cap is on top of the valve cover so oil pretty much drips down over everything on its way to the sump).

+1

[Matt sachs]

Agreed, its not a big deal. There is plenty of oil left in the oil galleries of the block. One trick you might be able to do is to fill the new filter with new, clean oil when you replace it. This will get the oil pressure up a smidge quicker, however,I dont think it will make a difference in the life of your engine.

[markpierce]

I expect my diesel engine will be operating long after I've turned to dust, even with much less frequent oil changes. Follow the manufacturer's recommendations.

[Ironhorse74]

Originally Posted by Dockhead

I change my oil fairly frequently -- three or four times a year, so usually less than 100 hours.

On the theory that a diesel engine pukes a lot of nasty things into the lube oil -- soot, acids -- and will be much happier with clean oil. And it is so easy and cheap to do -- why not?

One thing which bothers me, however, is starting up after the oil change -- the engine running dry and making alarming noises for a few seconds. It can't be good for it!

I tried once cranking the engine over with the Stop button pressed -- and was rewarded with popped breakers.

What do you guys do?

I don't worry about it. If you are concerned and your oil filter placement allows it, fill the filter with oil when you change it.

Just an FYI. I think you are putting yourself through a lot of unnecessary grief changing oil that often. I have managed fleets. One was the largest OTR trucking company in the US. We ran oil sampling programs and regularly retired trucks with 750,000 miles on them with the original engine oil. I realize your boat is not an over the road truck, but every hundred hours seems excessive.

Just my .02 your mileage may vary

[S/V Antares]

I am more concerned that you blow breakers when cranking...Whats up with that?

[emeraldsea]

When i install and electric oil change pump, I thought about teeing it into the oil circulation and using also as a pre-lub pump.

As said, really not necessary, but I am going to put in a block heating system, especially since I'm in a colder climate. You can also get magnetic oil pan heaters for not much $.

[hellosailor]

Pretend your boat is a seaplane and fit an electric oil pressure pump to it. Before you start the engine, you engage the oil pump and build oil pressure, THEN you start the engine.

Although these days...any good oil should have thin-film properties that ensure there is still a coating of oil on all the wear parts, even when the engine is "dry" at start up.

Mercedes used to design their engines to burn about one liter per thousand kilometers (in diesel cars) with the rationale that "oil is cheaper than piston rings" so just consume it and change it as needed.

Are you bothering to send out engine oil samples, to see if you really need those changes? Or just throwing out perfectly good oil?

[svcattales]

This is a little off topic, but you can minimize engine wear from cranking after an oil change, by changing your oil less frequently.

Another option to reduce oil change frequency is switching to synthetic oil. I now put 200 hrs on each engine before changing oil instead of the 100 hrs recommended by Volvo (I still change filters at 100 hrs.) I believe the synthetic oil also minimizes engine wear during cranking after an oil change since it is a better lubricant.

After switching to synthetic, I had the oil analyzed and it was still in good condition. The synthetic oil stays cleaner and at 200 hours it is not carbon-black color like conventional oil and looks like a dark caramel color. The synthetic stuff doesn't vaporize inside the cylinder during the power stroke like mineral oil does. That's one of the reasons it stays cleaner and lubricates better. I could probably go 250 hrs, but I'm being conservative.

The cost of synthetics is less than double the cost regular oil so I'm saving money and reducing a "pain-in-the butt" job by half.

[psneeld]

I have yet to read a definitive study that says synthetic for average engine use is warranted.

Gears cases probably...but an engine with combustion products NO!!!

Even dino oil lasts just fine..it's combustion products (and synthetics accumulate them just the same) or over temps that require the average boater to change oil..mostly as a seasonal thing due to the overall lack of hours.

As an assistance tower...I beat the living daylights out of a 454 gas engine. Over temp for hours on end, hard starts on a cold engine, etc...etc...going on 10 years and over 5000 hours on a GAS engine with regular CHEAP dino oil every 200 hours of operation.

Am I lucky??? Nopre...the other 5 boats in the fleet get the same treatment with the same results.

!00 hour oil change???/ Sounds like 3000 mile oil changes to me...a bit overkill.

Yes...after severely overtemping the engime for SEVERAL HOURS...I change the oil....only a fool wouldn't...but every 100 hours on ANY engine under normal use just seems like overkill to me.

[Chief Engineer]

Originally Posted by Ironhorse74

I don't worry about it. If you are concerned and your oil filter placement allows it, fill the filter with oil when you change it.

Just an FYI. I think you are putting yourself through a lot of unnecessary grief changing oil that often. I have managed fleets. One was the largest OTR trucking company in the US. We ran oil sampling programs and regularly retired trucks with 750,000 miles on them with the original engine oil. I realize your boat is not an over the road truck, but every hundred hours seems excessive.

Just my .02 your mileage may vary

Say what?????

[svcattales]

Originally Posted by psneeld

I have yet to read a definitive study that says synthetic for average engine use is warranted.

Gears cases probably...but an engine with combustion products NO!!!

Even dino oil lasts just fine..it's combustion products (and synthetics accumulate them just the same) or over temps that require the average boater to change oil..mostly as a seasonal thing due to the overall lack of hours.

As an assistance tower...I beat the living daylights out of a 454 gas engine. Over temp for hours on end, hard starts on a cold engine, etc...etc...going on 10 years and over 5000 hours on a GAS engine with regular CHEAP dino oil every 200 hours of operation.

Am I lucky??? Nopre...the other 5 boats in the fleet get the same treatment with the same results.

!00 hour oil change???/ Sounds like 3000 mile oil changes to me...a bit overkill.

Yes...after severely overtemping the engime for SEVERAL HOURS...I change the oil....only a fool wouldn't...but every 100 hours on ANY engine under normal use just seems like overkill to me.

I doubt you will see a definitive study on use of synthetic oils because the individual private users (particularly boaters) probably have huge variations on how they use their engines; how many days of non use; the climate they operate in; whether they "baby" their engines or run them hard; how they maintain them; etc.

Congratulations on the longer intervals you are getting with "dino oil" and I suspect your equipment is heavily used; the boats don't sit around idle; and you are maintaining them well. I believe the best thing you can do for any marine engine is to run it often. Using dino oil in gas engines should work just fine and I use it all the time in the "family truckster." Perhaps you could get 400 hours from synthetic oil instead of 200 and save yourself some time an money.

On the other hand, using synthetic oils in marine diesels is more important than using it in gas engines. Compression and combustion temps in diesels are much higher than gas engines and that's why "dino oil" turns black very quickly in a diesel. The vaporization of "dino oil" puts carbon and other harmful products in the oil and that's why change intervals recommended by manufacturers is often about 100 hrs. I use my boat heavily during winter months and hardly at all during Florida summers. When I was using "dino oil" I would have to change the oil after a winter cruise so all those harmful combustion products would not corrode my engine during the summer. By the time time winter comes again I have 7 or 8 month old "dino oil" that must be changed again before the next cruise because dino oil degrades with time. With the synthetic oil, I change it once a year and I don't have to change it in the Bahamas where there is nowhere to dispose of the used oil.

I could probably get more than 200 hours out of the synthetic oil, but that is usually all I need for a winter cruise. If the winds are on the bow and I have to put 250 hours on the diesels, that wouldn't bother me at all.

For less money and less work, I think synthetic oils are a great deal for boaters with diesels. From what I read, synthetics oils are better lubricants and that is enough justification for me to use them. Any other opinions on synthetic oils for marine diesels?

[SailBerkeley]

As for the original post, I wouldn't worry about it too much...

[Tellie]

No concern at all. There is no dry issue after an oil change. If there were you'd be dry everytime you started your engine after it sat for more than a day. To even further the point you should be warming the engine up a bit before you change the oil. This will help the oil flow easier and will coat the engine with more oil than if it sat for a day.