My dad likes to change motor oil only after getting the car up to operating temp. His argument is that all the crap is pulled in (mixed) with the oil to allow more of the contaminates to drain out.

My argument is: "Yeah, but by running it you have a good amount of oil thrown all throughout the motor and you dont let the pan drain long enough for all of that oil to drain out."

I just say drain it cold. All of the oil is in the pan and draining hot oil sucks anyway

What do you guys do?

-Scott.

 

I drain mine hot,and I drain it for an hour or more,so Ithink you could say it's drained well. Hot oil will drain quicker than cold oil so it would tend to pull more contaminates out with it. You could drain it cold,argueing that everything is in the pan,but contaminates tend to stick when the oil is cold,so what might be left in the pan? You could warm the pan so the oil drains better,but if your changeing every 3k it shouldn't make too much differance if a little oil is still in there anyway.

 

I always drive mine up on the ramps hot, let it cool then drain it. The only difference in this and draining hot is like the above states, there is a bit more left in the pan. I think only a fanatic would think it's enough to make any difference, though. An oil analysis cold/hot would be the only way to show what happens.

 

I do it how ever the car is when I fell like doing it. Hot, cold, it doesn't matter.

 

Hot.

 

i warm car up for about 5-10 min then drain her.. just what ive always done

 

i warm it up too - watch that y-pipe, it'll getcha

 

Operating temp.

 

thanks for the replies.

I'm thinking hot (operating) with a long drain time to let all the oil come from the top of engine down into the pan and out......if you have time.

-Scott.

 

Another vote for hot...

 

I don't think I have ever drained completely cold oil.

 

How long could it possible take for oil to (mostly) settle in the pan after running the engine at operating temp?

The manual (for when checking oil level) Says to warm up the car to operating temp, and then wait 5 min for the oil to settle.

So by the manual.. 5 min is about how long it takes for most of the oil to settle. And since it takes me at least 10 min to get the car up (I don't have ramps) Then I preffer to drain the oil hot/warm

 

I dont drain my hot but i let it cool so i can drain it without burning my hands.

 

Let me guess, you just want to drain it cold to disagree with your dad. Draining it hot gets all the crap in the engine up and suspended in the oil. If you worried about the miniscule amount that was circualting in the engine, do what I do. WhHen I'm gonna change the oil Saturday morning, Friday night I'll park it on the ramps and let the oil drain all night.

Best of both worlds, Right???

 

I vote cold. No reason, just how I do it.