Cranking Over After Oil Change

[Tellie]

Originally Posted by Chief Engineer

Say what?????

Sure, I haven't changed my oil in my 72 Vega since it came off the show room floor. It purrs like a kitten and there isn't a spot of rust on her.
I'm sure it was a typo, but it was a good catch.

[markpierce]

Originally Posted by 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.

If memory serves, my engine builder recommends that its JD 4045Ds should be operated at least once every two weeks. While I'm an ignoramous, I presume this is to assure the internal parts are kept lubricated.

[Tellie]

Originally Posted by markpierce

If memory serves, my engine builder recommends that its JD 4045Ds should be operated at least once every two weeks. While I'm an ignoramous, I presume this is to assure the internal parts are kept lubricated.

Of the many things that can harm an engine, high on the list is just letting them sit unused for long extended periods of time. Especially marine engines of any type.

[Astrid]

One needs to run them once in a while to evaporate condensation and to coat the internal parts with a film of oil to prevent corrosion.

[Duke 48]

Would it be wise to switch to decompression and crank the engine for a few seconds before starting after an oil change?

[DRS]

Originally Posted by Tellie

Sure, I haven't changed my oil in my 72 Vega since it came off the show room floor. It purrs like a kitten and there isn't a spot of rust on her.
I'm sure it was a typo, but it was a good catch.

I believe he meant 750,000 on the original engine. Not engine oil. I'm in that business too and we see that kind of mileage and more all the time.

[ggray]

Originally Posted by Duke 48

Would it be wise to switch to decompression and crank the engine for a few seconds before starting after an oil change?

That's what I do (with fuel shut off handle pulled), also whenever my engines haven't been run for a while. Once the low pressure alarm stops, I then throw the levers back, and start the engine.

[senormechanico]

I've worked on sewing machines which had 750,000 miles on the original oil...

[Tim Schaaf]

Just today, I attended a seminar by Larry Berlin of Mack Boring, Yanmar distributors, etc. etc. and to the question of using synthetics, he answered that it was OK as long as the specs were the same, but NOT to decrease the frequency of oil changes. The reason is that the additives that absorb the combustion by products last no longer in synthetic oils than other oils.

[Ironhorse74]

Originally Posted by Chief Engineer

Say what?????

Just what you read. In seven years there, we never had an oil related failure. We did have a very aggressive oil sampling program. It was not unusual to retire trucks with 600-750k miles and the original oil in the engine. About 2500 prime movers in the fleet. First sign of oil breakdown , fuel or metals in the oil. The problemwas fixed and the oil changed.

[Anonymous7500]

Originally Posted by Ironhorse74

Just what you read. In seven years there, we never had an oil related failure. We did have a very aggressive oil sampling program. It was not unusual to retire trucks with 600-750k miles and the original oil in the engine. About 2500 prime movers in the fleet. First sign of oil breakdown , fuel or metals in the oil. The problemwas fixed and the oil changed.

I am assuming that in your sampling program the oil was collected from a filter that had been removed at a regular interval. Usually about 15,000 miles or so? Replacing the filters on these vehicles requires adding about a gallon of new oil to the system. A typical system in these trucks has a capacity of around 10 gallons. Over the 750,000 miles you would have replaced 50 gallons of oil lost to filter changes. Though not technically an oil change, the original stuff is long gone. It isn't that I think the oil wouldn't last 750,000 miles, but there isn't any way that a filter is going make it that far!

[Dockhead]

Originally Posted by Tim Schaaf

Just today, I attended a seminar by Larry Berlin of Mack Boring, Yanmar distributors, etc. etc. and to the question of using synthetics, he answered that it was OK as long as the specs were the same, but NOT to decrease the frequency of oil changes. The reason is that the additives that absorb the combustion by products last no longer in synthetic oils than other oils.

There is a lot of information that synthetic oil is quite harmful to marine engines. See this:

Oil for yacht engines

The author is a metallurgist and lubrication engineer who worked for years for Shell formulating lube oils.

The API grade of oil is apparently quite important, and higher grades are NOT better, and according to the author, synthetic oil can be extremely harmful to a marine engine.

From the cited web page:

"A couple of boats ago I had a Prout cat with an almost new but run in Yanmar 2gm in it. We took it on a long delivery trip in a flat calm, so the engine was running at steady revs for about 30 hours. By the time we got there it was drinking oil, never having consumed any beforehand.

Subsequent discussions with both Yanmar technical and the Shell oil laboratories suggested that we had unwittingly committed two sins, the major one being that we had followed the normal idea of being kind to our engine by giving it good oil - a semi synthetic. Yanmar insisted that putting a higher grade modern oil in an old design engine was asking for trouble. I was sceptical so I spoke independently to Shell laboratories and to my surprise they said the same thing. They went so far as to say that we should never use synthetics in old design engines since there were components in the oil that could cause accelerated wear."

[Ironhorse74]

B

Originally Posted by Anonymous7500

I am assuming that in your sampling program the oil was collected from a filter that had been removed at a regular interval. Usually about 15,000 miles or so? Replacing the filters on these vehicles requires adding about a gallon of new oil to the system. A typical system in these trucks has a capacity of around 10 gallons. Over the 750,000 miles you would have replaced 50 gallons of oil lost to filter changes. Though not technically an oil change, the original stuff is long gone. It isn't that I think the oil wouldn't last 750,000 miles, but there isn't any way that a filter is going make it that far!

We specified all engines with oil sampling ports so we did not remove filters for sampling. We changed filters according to the oil analysis. No where close to every 15k more like 50k or so. Only when analysis called for it.

[Maine Sail]

Rotella 15W-40







Exactly as it came off..


At...


Oh and my friend in NH who commutes to Boston daily has over 800k on an early 90's Accord. Dino oil changed at the cheapest shop, with el-cheapo filters every 8-12k. Original motor and transmission. He's going for 1,000,000 but I think rust will get him first..

[Joli]

When we installed the new engine we also installed a pre-luber that will pressurize the oild gallery to about 70 psi. It runs prior to starting the engine and then runs for another minute or two after shut down to reduce coking.

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?