Hot or Cold oil change?

[JeffKeryk]

I prefer cold. Easier to work on.
Does the oil drain more slowlt? Sure. So I give it a few more minutes.
Additionally, in cases where the filter is in an awkward location (Honda K24, etc), perhaps less spillage occurs.

 

[tiger862]

I start drive on ramp then change oil. 4 vehicles. The only one I don't like to do is Impala as why oil filter next to exhaust.

 

[MasterSolenoid]

I change it 'hot' right after a drive.

I always figured you'd get better flow.

But also because right after the oil change I start the engine to fill the Filter and
figure there may be a little more oil clinging to cylinder walls and all other metal-to-metal parts,
thus avoiding wear on initial startup.

 

[Jackson_Slugger]

I drain hot because I think contaminates drop down to the pan when warm and I think there is a better overall flushing...

Originally Posted by FordCapriDriver
I've always done them cold because i don't fancy getting my arm or hand burnt touching a hot exhaust or oil.
And as we know, on BITOG the ultimate performance spec is : "It hasn't blown up yet"

And certainly i have never had an engine blow up yet from doing oil changes cold lol


I drain the oil hot, but let my 24v Sable cool before I tackle the filter as the exhaust manifold wraps around it...

 

[Lapham3]

I generally do my oil changes outside or with an open garage door, as i like to do them in spring and fall when the outside temps are neither too hot or cold. The conditions are comfortable and I usually change the oil with the engine pretty warm, but not piping hot. I would also often raise the vehicle to get an attitude to promote as much drainage and minimal left in the pan. This has been my mode for over 50 years. In the carburetor days of the 60's-early 80's some of the cars were well used before my ownership and sludge wasn't rare. I would let them drain quite a while and sometimes towards the end a splash of mineral spirits or gas to wash the remaining gunk/chunks out. In more recent years modern electrics/electronics, fuel injection and lubricants have made a big difference in the frequency and results of the basic oil change.

 

[old1]

Back in the 60s 70s 80s even 90s I always got the oil hot before draining it. Now I just drive around a block or two, then get it driven up on my ramps. By then it is warm, but not hot, and I figure it is a good compromise between hot and cold. Oil is a lot different now than when I was a teenager.

 

[Propflux01]

I drain warm. If for some reason it's a cold drain, I'll leave it to drain overnight and refill in the morning.

 

[donnyj08]

Warm enough to drain easily, cool enough to not burn my hands.

My comfort is a higher priority than the worry of contaminants in suspension. The filter catches contaminants of size anyway on the next drive.

We overthink almost everything here at BITOG.

 

[ka9mnx]

Originally Posted by Propflux01
If for some reason it's a cold drain, I'll leave it to drain overnight and refill in the morning.

That's what I did in my cold drain days. Time permitting!

 

[supton]

Originally Posted by SR5
I was always told to do an oil change when the oil was hot or warm, I think the logic was that more contaminants were in solution and the oil drained out faster.

But now I think on that logic, if the oil needs heat to keep contaminants in solution then I should have changed the oil long ago and I already have an engine full of sludge and varnish.

That is my thinking. Back in the day, it may well have mattered. Either because the oil was too thick to drain fast, or because stuff could fall out of suspension--hot oil might not "pick it back up" into suspension, but once warmed up, it might flow out of the pan all the same.

Today though, I don't bother. Cold 5W30 flows fast enough for me to change in most any weather I'd care to change it in (and 0W20 at even colder temps!). So I change it cold. I don't have many miles doing that, maybe 140k on one Camry, 75k on the other, so that's anecdotal evidence, but all the same... no issues here.

Now, diffs and items like that are going to drain better when warm.

 

[geeman789]

Does more HOT oil drain out of an engine ?

Or does HOT oil, left to settle completely overnight, then drained COLD the next day get more used oil out of the engine ?

I think the second option will actually remove more oil. Any engine that has been running in the previous couple of hours will have oil throughout the engine that has not yet drained down. If I check my oil after driving the car, waiting an hour ALWAYS shows a noticeably higher level on the dipstick. Or you could let the hot oil actually drain for an hour or more ...

 

[supton]

Originally Posted by geeman789
Does more HOT oil drain out of an engine ?

Or does HOT oil, left to settle completely overnight, then drained COLD the next day get more used oil out of the engine ?

I think the second option will actually remove more oil. Any engine that has been running in the previous couple of hours will have oil throughout the engine that has not yet drained down. If I check my oil after driving the car, waiting an hour ALWAYS shows a noticeably higher level on the dipstick. Or you could let the hot oil actually drain for an hour or more ...

I've wondered that too, but... there's always a bit left in the bottom of the pan, and then there's some left in the head(s) too, places where it'll never drain on its own.

Yeah, there might be a few ounces on the walls, in the process of draining, that if you drain hot you won't get. But I strongly suspect that after 10-15 minutes of sitting, it's mostly there and just too small of an amount to be concerned with. After all, most of us are changing oil long before it's actually bad.

Sometimes I wonder if the guys who do spill and fill on their transmissions (you know, just a pan drain, not a full fluid exchange) worry about getting all their motor oil out when they change engine oil.

 

[Gebo]

I do warm/hot unless I am in a position to let it drain overnight and then I change it cold.

 

[4WD]

That reminds me … for those who think it takes forever for oil to drain, or all this "stuff" is left behind … just pour in half a quart of some leftover oil in while the plug is still out … right back out and pretty darn clean …

 

[Malo83]

Originally Posted by ChrisD46
Always hot / warm ... You want contaminants in suspension and hot / warm oil drains the quickest .

 

[dave1251]

Hot but not 2nd and 3rd degree burn hot when you touch the oil.

 

[wemay]

Warm to hot

 

[JohnnyJohnson]

Originally Posted by Malo83
Originally Posted by ChrisD46
Always hot / warm ... You want contaminants in suspension and hot / warm oil drains the quickest .

Yes I believe even suspension of contaminants is important if you want good consistent UOA. I usually do mine just after I've gotten home from someplace. I run it for a few minutes then put it up on the ramps and getter done.

 

[WondrousBread]

I always schedule my oil change after a long trip that will get my oil up to temperature, then I park over my oil change pit.

Head inside, make a coffee, drink the coffee over 30 minutes while I get all the supplies together.

Then go out to the still hot (but not scalding hot) engine and begin draining.

I'm not sure if it actually puts more contaminants into suspension, but it definitely makes the drain faster and easier.

 

[tblt44]

Warm, sometimes in the morning.
Can,t say cold because in florida in the morning it's usually in the 80s