Oil changes: Warm or Cold?

[CobyRupert]

OK let's continue.

If hot oil causes metal particulate to be suspended in the oil, where is this particulate when the oil has settled, on bottom by drain plug? Floating on top of oil pool in pan that will get drained when the plug is pulled? There are many more non-metallic components that are inside an engine that a magnet will not affect.
Two quarts of oil, one always at 50 and the other at 140 degrees. Drain them, how much would be left after waiting a certain time? Sure in a minute there would be a difference but what about 10 hours.

Cold or Hot just depends on how much time you have to drain the oil.

Slow day today

Dave

:thumbsup:
I agree.

...but I waited until the oil was warm after using tractor anyways. Then I let it drain for 24 hours. So I should be good. :laughing:

 

[THEPARTYHOUND]

OK let's continue.

If hot oil causes metal particulate to be suspended in the oil, where is this particulate when the oil has settled, on bottom by drain plug? Floating on top of oil pool in pan that will get drained when the plug is pulled? There are many more non-metallic components that are inside an engine that a magnet will not affect.
Two quarts of oil, one always at 50 and the other at 140 degrees. Drain them, how much would be left after waiting a certain time? Sure in a minute there would be a difference but what about 10 hours.

Cold or Hot just depends on how much time you have to drain the oil.

Slow day today

Dave

I respectfully disagree. Place a nut in some oil. It sinks. Place a small metal shaving in oil. It will also sink. It's about density. If a tractor has been sitting for a few days, I think there would be plenty of contaminants sitting on the bottom of the oil pan that would be more readily evacuated when mixed and suspended in the oil.

 

[Pete6114]

Everything i owe gets it's oils changed hot, after use, but i do wait for 15-20 minutes past the heat-soak. Not even my walk behind mower gets it's oil changed cold.

 

[Gary Fowler]

It is not only cold engine to think about. I decided to change the oil in my motorcycle once when it was about -20F outside. I cranked up the engine, let it get hot and then drained the oil which came out easily. The problem came when I started trying to get the new oil to pour back in. It had been stored in the unheated garage and since it was 50W oil it was very thick and flowed very slow down thru the engine fill spot and even out of the bottle. I ended up taking the oil in the house and warming it up in a hot water bath for about 15 minutes. I thought about microwave but decided against that since it might melt the plastic bottle also.

 

[LouNY]

It is not only cold engine to think about. I decided to change the oil in my motorcycle once when it was about -20F outside. I cranked up the engine, let it get hot and then drained the oil which came out easily. The problem came when I started trying to get the new oil to pour back in. It had been stored in the unheated garage and since it was 50W oil it was very thick and flowed very slow down thru the engine fill spot and even out of the bottle. I ended up taking the oil in the house and warming it up in a hot water bath for about 15 minutes. I thought about microwave but decided against that since it might melt the plastic bottle also.

Just think of how well that straight 50 was behaving in that engine when you fired it up,
how much nicer would a good synthetic 20W-50 have been to that engine.