Unusual Oil Change... "Method"???

[TomYoung]

Well, do people here think hot/thin oil holds solids in suspension better than water like hot oil … Or is it a sweep effect …?
Likely not a dimes worth of difference …
2 ounces in 8 quarts for me LoL … However warm it gets going on the ramps …

If you have spent any amount of time in the kitchen, you'd know that stuff dissolves easier in hotter liquids.

 

[4WD]

Maybe "theoretically", but I've seen no real proof. Think about it, every time an engine is ran and then shut down, all the oil that will ever drain down to the oil pan does so if it sits for a few hours. So if you drain the oil cold and let it drain for a day or two, the only oil that you are essentially draining cold is the oil in just the sump/oil pan. If it drains to the point of zero dripping, that's all that's going to drain out. And if you let it drain cold for a day or two to the point of zero dripping, it certainly would be draining out more oil volume than if you did a hot drain for only15-20 minutes. I have never seen an oil drain hot stop dripping after 15-20 minutes.

Look at post 35 above by Snagglefoot. Per his observations he hasn't seen any permanent sediments collect in his oil pan from doing cold oil drains.

Seems reasonable … How many have this sump build up problem - on this site it would have been posted by now …
Filters and drain plugs for the

 

[4WD]

If you have spent any amount of time in the kitchen, you'd know that stuff dissolves easier in hotter liquids.

What are you dissolving ?
Multiphase (high temperature) industrial liquids have been part of my job for decades - just like solids control has …
I need a kitchen ?

 

[ZeeOSix]

If you have spent any amount of time in the kitchen, you'd know that stuff dissolves easier in hotter liquids.

Not the same ... water is a solvent, oil is not. Besides, the particles in oil are not "dissolvable" by oil. Suspeded particles are not the same as dissolved particles.

 

[Warstud]

I'm surprised this thread wasn't LOCKED

 

[TomYoung]

Maybe "theoretically", but I've seen no real proof. Think about it, every time a hot engine is ran and then shut down, all the oil that will ever drain down to the oil pan does so if it sits for a few hours. So if you drain the oil cold and let it drain for a day or two, the only oil that you are essentially draining cold is the oil in just the sump/oil pan. If it drains to the point of zero dripping, that's all that's ever going to drain out. And if you let it drain cold for a day or two to the point of zero dripping, it certainly would be draining out more oil volume than if you did a hot drain for only15-20 minutes. I have never seen an oil drain hot stop dripping after 15-20 minutes.

Look at post 35 above by Snagglefoot. Per his observations he hasn't seen any permanent sediments collect in his oil pan from doing cold oil drains.

If you want the ultimate oil drain, drain it hot and let it drain overnight so it stops dripping completely. That's typically the way I've done it for years. But I have done a few "cold drains" in my time where I let it sit at least a day or two until it stops dripping.

Would you not agree (and correct me if I am wrong) that the most prevalent practice by far is the "hot" oil drain? If so, then the burden of proof would be on those advocating a change to the status quo... to prove that they have an equivalent or better mousetrap.

 

[ZeeOSix]

Would you not agree (and correct me if I am wrong) that the most prevalent practice by far is the "hot" oil drain? If so, then the burden of proof would be on those advocating a change to the status quo... to prove that they have an equivalent or better mousetrap.

Sure, the "most prevalent" way to drain oil is when it's hot/warm. But there is no proof that draining oil cold and letting it drain until it no longer drips is a worse way to do it. The length of the OCI is way more critical than the way the oil is drained. Of course, if someone did a cold oil drain and only let it drain for 10-15 min that's not going to get as much oil out as a hot drain for 10-15 minutes. But if an oil pan is drained either hot or cold until it no longer drips any oil (however long that takes) then no more oil can be drained.

Like I said in an earlier post edit - if you want the ultimate oil drain, drain it hot and let it drain overnight so it stops dripping completely. That's typically the way I've done it for years. But I have done a few "cold drains" in my time where I let it sit at least a day or two until it stops dripping. In both cases, as much oil as possible was drained out of the engine. If there are settled sediments in the bottom of the oil pan that won't get re-suspended in the oil when the engine runs, then they won't come out with a hot oil drain either.

 

[BHopkins]

Cool idea on the vacuum. I'm half tempted to try it next time I do an oil change, just for kicks and giggles. But it really doesn't matter much to me. I have a Fumoto valve on my wife's Outback, and use an oil extraction pump on my E350. So no mess, no fuss. Never have to worry about where the drain plug is going, or how to hold on to it.

https://www.motortrend.com/how-to/change-engine-oil-hot-or-cold/#:~:text=Most%20oil%20experts%20say%20it's,engine%20than%20when%20it's%20cold.

Most Oil Experts Say It's Better To Drain The Oil When It's Hot Instead Of When It's Cold, For Several Reasons:​

• Oil viscosity is thinner when it's hot, so it drains more quickly and completely out of the engine than when it's cold.
• On a hot engine, contaminants are more likely to remain suspended in the oil than when the oil is cold, increasing the chances they'll be expelled from the engine during the draining process.
• Today's high-tech OHC engines hold oil in a lot more places compared to old-school motors, so it's gotta be warm (and thin) to escape from all those upper-end crevices.

I think everyone agrees that hot motor oil drains more quickly than cold motor oil. But the second and third reasons really seem theoretical at best, and actually sound a little like junk science.

The whole idea that there are solids that will fall out of suspension if the oil is allowed to set in the sump overnight, or even a few days, seems absurd. First, the oil filter is supposed to be capturing particles down to the size than it is rated for. Second, modern motor oils are designed to keep the remaining particles in suspension, in such a way that the particles do not cause wear.

If the theory, that particles fall out of suspension in just a short time, is valid, then the theory that they will be sucked back up, off the bottom of the oil pan, just by running the engine for a few minutes, doesn't seem valid.

The third item is also a little absurd. Assuming the motor oil was up to temperature whenever the engine was last shut down, then the oil is going to drain out of all these thin "crevices" at that time, and end up in the sump. So, if you drain cold, you are going to capture as much as possible, that would have been in these "crevices". If you drain hot, you have just pumped oil up into all these crevices, only to have to wait for them to drain, again.

IMHO, the only valid reason to drain hot is convenience. And if you use an oil extraction pump, hot oil is a major convenience. But until someone has data to show that a hot drain captures more crud, I'm a non-believer.