Engine Oil Change

Should oil be changed when engine is hot or cold???

Greetings,
Mr. k. The general consensus is a HOT oil change. Any contaminants should be in suspension, hot (thin) oil flows much better than cold.

Neither. I have always been told (although via auto techs many years ago) to run the engine to warm up the oil, let is sit for a little while, then change it warm.

But hey... what do I know. I assume different manufacturers probably have different ways the recommend. May want to check your service manual or call a diesel shop and see what they say.

Hot, every manufacturer's materials suggest warmed up.

Following a run, warm oil flows better than cold,
contaminants in the oil are more likely to be in suspension, vs settled out in the pan, so they will get out... which is primarily why we change the oil...

with a practical caveat: if engine parts are going to burn you doing it "hot", your eternal salvation won't be put in jeopardy by waiting a short while for that particular external to cool a bit...

Or, is this topic similar to anchor selection?

RB

Hot

And that reminds me I need to do dat.

Hot. Let it cool enough to not be burned on contact. IE ~140F oil temp.

Hot but largely because the oil flows better. I just did mine yesterday and despite warming the engine up it still took 40 minutes for the oil to drain out. Note that me engine has a drain hose plumbed into the pan and oil removal is done through the 1/8" ID hose by gravity flow, so it is SLOW. Cold the oil would take hours to drain through that hose. On my other boat there is a metal tube plumbed in to the bottom of the pan with an oil change pump attached. Warm that engine can be drained of oil in under a minute.

TDunn said:

On my other boat there is a metal tube plumbed in to the bottom of the pan with an oil change pump attached.

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I have two of these (oil change pumps), but one has failed. They're gear pumps with a plastic housing, but they look pretty rugged. That model is no longer for sale.

I've used cheap-o ($15) pumps from Amazon, but they're clearly very frail, and I've already burned one out by running it for too long (trying to transfer fuel).

I've also seen expensive ($150-$200+) pumps advertised. I can burn out a lot of cheap-o pumps before that becomes cost-effective.

Any other options?

I go either way (on the oil change that is, hot or cold). I have a hose at the bottom of the oil pan and my pump doesn't much care if the oil is cold, still only takes a couple of minutes max.

Greetings,
Mr. CT. I use a Reverso pump plumbed into the drain plug in the engine sump. Other than a worn out impeller (easily changed and not expensive) it has worked flawlessly over 10+ years. Similar to one of these BUT with a neoprene impeller. (old style, I suppose) Reverso DC Pumps
Yup, expensive.

I do it hot and have never come close to comming in contact w the hot oil. I freqiently use the plastic jugs that you buy distilled water in at the Safeway store. I usta worry about the plastic melting and having hot oil in the bilge. Never has happened and I frequently have used better containers.

But I get everything ready to do the pump out as soon as the engine stops. Just to minimize things settling out of the oil. Perhaps it's a waste of effort. I'm not sure but I do what I do. I do the same w my cars.

[emoji106] Always when the oil is hot.

TDunn said:

Hot but largely because the oil flows better. I just did mine yesterday and despite warming the engine up it still took 40 minutes for the oil to drain out. Note that me engine has a drain hose plumbed into the pan and oil removal is done through the 1/8" ID hose by gravity flow, so it is SLOW. Cold the oil would take hours to drain through that hose. On my other boat there is a metal tube plumbed in to the bottom of the pan with an oil change pump attached. Warm that engine can be drained of oil in under a minute.

Click to expand...

Do you know why such a small ID (1/8") hose for your oil drain? It seems strange.
I change my oil hot about 14qts., up through a tube, not dipstick tube, with an engine mounted hand pump. A lot of pumping but it doesn't take too long.

Hot.

Tom.B said:

Neither. I have always been told (although via auto techs many years ago) to run the engine to warm up the oil, let is sit for a little while, then change it warm.

But hey... what do I know. I assume different manufacturers probably have different ways the recommend. May want to check your service manual or call a diesel shop and see what they say.

Click to expand...

The ONLY reason they say to wait after running the engine is that the lawyers wrote the manual. they don't want you to get BURNED and sue thier asses.

Otherwise please tell me the logic, oh wait, I'm in the wrong place for that. Sorry

Warm oil to normal operating temperature. I use a hand evacuation oil change pump ( Mueller ) and it makes the removal much easier.
I usually carry enough spare oil to do a engine, generator and engine transmission change in case in not near a retailer. I found a yesterday that one of the gallon bottles of Rottela 15W40 had leaked at one of the bottom corners, looks to me like the containers are not as sturdy as they used to be. I store them in a fluid tight bin so the spill was contained. I padded the new spare oil on oil spill diapers to give them a softer surface. If you carry spare oil containers it might be worth checking.

Hot. But i always toss down another quart as it finishes draining out as a 'final flush'. Purely personal opinion as to its effectiveness.

Bought a Fumoto oil pan valve. Best $45 bucks I've spent. Almost no mess on an oil change. And very little mess on changing the filter (just technique).

Or you could have your local shipyard or yacht guy do it for ya.

Hot after cruising. Have oil change pump plumbed into oil pan drain. Stick the hose in a waste oil container and turn on the pump. No way to get burned. Change the filter after its cooled down.

Ted

Most Beta engines include a built in, integrated oil change hand pump into their engines. Is this considered desirable or just fluff? If it's desirable, is this a common aftermarket upgrade that you guys make.

I know it's relatively tight quarters in most engine rooms, I assume removing an oil change plug can be a challenge.

cappy208 said:

Hot. But i always toss down another quart as it finishes draining out as a 'final flush'. Purely personal opinion as to its effectiveness.

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Cappy,

I thought I was the only crazy guy who did that!

Rob

I drain while the oil is warm/hot, because it flows easier through our X-Changer pump/system... and presumably because any contaminants are in suspension then.


Then I change the filters and refill the next day when the engine room is cooler and when nothing is warm to the touch (especially filters). This usually starting with fresh oil that I've kept in the cabin, so slightly warmer than it would have been if only just brought aboard from outside, in our Fall temps.


-Chris