Draining oil hot or cold questions?

[SHOZ]

When I drain I use a deep socket and let the plug drop in the pan. Then just fish it out with a magnet.

My biggest issue is the wind when changing out the oil on the driveway. Sometimes I rig up some wind blocks.

I need to change the oil in the Gen Couple and will probably do this on a cold engine. The wind will be in a more favorable direction and a bit warmer tomorrow.

 

[SilverSnake]

The hotter the better,

 

[Rick in PA]

Originally Posted By: SilverSnake
The hotter the better,


I was going to say that. I like the oil to come gushing out.

 

[Eddie]

Modern oil like 0w20 drain nicely at ~ 100 F. In the 1950 when 30 weights flowed like molasses then it had to be hot. I see no reason to boil my hands with 200 F oil. Ed

 

[Warstud]

Originally Posted By: SHOZ
When I drain I use a deep socket and let the plug drop in the pan. Then just fish it out with a magnet.


I use a box end wrench and the plug usually doesn't drop into the pan.

 

[CR94]

Originally Posted By: StevieC
I always do an oil change after coming back from somewhere so the oil has reached operating temperature along with the engine. I open the hood and put it up on the jack, get the safety stands in place, the catch pan in place, new oil etc. ready, rags, gloves on etc. This all takes about 20 minutes or so, so by then the engine & oil has cooled a bit and I find while the oil and filter is still very warm it's not burning/scalding hot ...
That's close to my current routine, except that I use makeshift ramps instead of jack+stands, and I restart the engine for a minute or so immediately before finishing taking the plug out, hoping to re-suspend any suspended junk that has settled out.

It was much easier to drain the Mazda hot, because I didn't have to take time to coax it up on the ramps and open an access door in aero shielding under the engine.

 

[4WD]

Originally Posted By: Donald
Warm is hot enough to drain the contaminants with the oil. Hot is fine but no need to get it so hot it will burn you.


Bingo ~ Doing it warm I have liberated and agitated what a Fram Ultra did not remove …
Not getting burned over hair splitting …

 

[Silk]

For me it's a time issue, cold oil runs out for a long time, hot oil slows to a drip in 5 or 10 minutes, just enough time for me to check all the under car levels, greasing if possible and check the brakes, tyre pressures, drop it down and do the top.

 

[mightymousetech]

Always with the oil at full operating temp. Always.

 

[StevieC]

Originally Posted By: mightymousetech
Always with the oil at full operating temp. Always.


Sounds like a Walmart Policy.

 

[eyeofthetiger]

Originally Posted By: StevieC
Originally Posted By: mightymousetech
Always with the oil at full operating temp. Always.


Sounds like a Walmart Policy.

You don't want to know how Walmart changes oil. I used to work there.

 

[StevieC]

There is a Walmart up by my parents and we would frequently go for ice cream at the shop that faced their service bays. My dad and I would be sitting outside the ice-cream place watching in horror what they were doing.

They certainly "roll back"-ed the service at that location. Always a horror story, always.

 

[cjcride]

Hot every time.
Cold would feel like waste of time and oil.

 

[CR94]

The temperature is not as important in itself as getting that plug out as soon as possible after the engine stops turning, before any suspended junk can settle to the bottom of the pan

 

[Garak]

Originally Posted By: mightymousetech
Always with the oil at full operating temp. Always.

Same here, but mostly out of habit. I've changed cold oil maybe once or twice in my life. The taxis, of course, were always hot.

 

[mobilaltima]

I usually drain it hot, and by hot i mean like 5 minutes after the vehicle is shut off. I'm impatient. But I always wear gloves

 

[Linctex]

Originally Posted By: CR94
....as important as getting that plug out as soon as possible after the engine stops turning, before any suspended junk can settle to the bottom of the pan


WHOAH there, partner!

It takes many hours for the "stuff" to settle out.

It doesn't happen "in seconds or minutes"

 

[Nyogtha]

^^^ Agreed! Unless your contaminants are large enough to be seen by the naked eye and fished out with your fingers as nuggets . . . in which case you have other issues.

Very small particles are settling in the Stokes flow regime, where the drag forces on the surrounding fluid are quite significant.

I change my oil at ambient atmospheric temperature, colloquially "cold", in spring or autumn. I put the vehicle on ramps and let sit overnight. To me this also provides a good practical test of remaining oil filter ADBV functionality; to me it shouldn't leak down overnight else what's the purpose for it being there on a daily driver?

 

[CR94]

Originally Posted By: Nyogtha
^^^ Agreed! Unless your contaminants are large enough to be seen by the naked eye and fished out with your fingers as nuggets . . . in which case you have other issues. ...
There's a wide range between too small to be seen and "nuggets."

 

[jakewells]

i like to drain mine when it is warm but not hot because i prefer not being cooked by the exhaust pipe or oil.