Consensus on Cold Oil Changes

[smcnair]

I've also heard to remove the filter first, then drain the pan.

Apparently some oil that's in some passages can make it back into the pan when the filter is removed.

Add this to the growing list of "things I did not know".

 

[Z15]

When the engine is cold, the oil tends to not flow very well. Which means if you change the oil on a cold engine, you may not be getting all of the old oil out.

 

[OR VietVet]

I have always done hot oil changes. When I was running shops, if we pulled in a customer's vehicle for an oil change, we let it run for 5 minutes before draining. Like @homesick said, that gets everything suspended in the oil and drains out more efficiently. It is just the way I was taught and I continue to this day. Also, less chance of old oil mixing with new oil. The importance of a good quality filter, like WIX, cannot be stressed enough.

 

[George B]

I tend to do them hot or at least warm. Never cold unless there is not an option. I am with the “contaminants in suspension” group

 

[Rocket Man]

I always do mine hot but I have quick drains that I just screw the hose on and it drains out o]without having to remove the drain plug. I pull the filter after it cools down though since that's always when I would spill hot oil on myself. I will have to check next time if pulling the filter results in a few more drips out of the pan since I leave that drain hose connected until the filter is changed. I was always taught to change oil hot and I'm too old to change now.

 

[easymoney]

I always have done it cold and let it drip…i figured i didnt want old oil up in the motor and leaving it over night to drip down inside motor into pan was what i wanted to do. after it stops dripping i put the plug in it and put 1/4 -1/2 quart of fresh oil in and pull the plug after a minute or two. Might see a little dirty oil come out but its probably not woth it. its rare that anything else comes out. I do see the point of the particles more suspended in the oil because of the motor was running but dont see the issue of oil being hot or cold as a factor. I live in texas so oil is always dripping fine. If you live somewhere cold it might make a difference though no experience with that.

 

[steve45]

Hot oil changes are an old wives tale. Sludge sticks to the pan, it doesn't float around in the oil. And if it did, the filter is supposed to catch it.

I've been doing cold oil changes for about the last 30 years and run most of my vehicles to about 300K, no problems.

 

[George B]

I would say the vast majority of oil changes happen hot or warm anyway. One thing I just thought was the first “cold” start of the day is the hardest as the oil has drained back more over time. That said I wonder about that cold start with less “prime”…
But, if you pre-fill your filter there shouldn’t be much difference.

 

[Mudsport96]

Hot oil changes are an old wives tale. Sludge sticks to the pan, it doesn't float around in the oil. And if it did, the filter is supposed to catch it.

I've been doing cold oil changes for about the last 30 years and run most of my vehicles to about 300K, no problems.

This here.
I didnt get the Silvy from the father in law until 394k miles. He being the slow "older" guy did them cold so he wouldnt get burned. So hot isnt necessarily getting more contaminated stuff out. Maybe before oil quality got better in the late 80s early 90s it made a difference

 

[SnowDrifter]

Doesn't matter.

Doing it hot only counts for lab analysis, with the goal being to exclude erroneous moisture contamination / fuel contamination from pulling the thing into the garage.

If you read internet advice about stirring up the oil to make sure you get particulates out and believe this applies to you, I'd carefully evaluate your maintenance habits and why you'd allow solids to build up in a liquid system.