Oil Change: Hot or Cold?
- Thread starter camrydriver111
- Start date
- Joined
- May 27, 2002
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- 653
I like to do the oil changes on my cars with the oil pretty well heated up. I attach a clear 3/8" tube to the Fumoto valve and get a very clean drain. Now, I'm trying to come up with a way to make the filter removal a bit cleaner.
4WD
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This will sound very BITOG - but one could argue if most of the oil is in the pan - and some particles settle overnight - just pulling the plug cold will dump the bottom particles and all the rest of the oil (with cold viscosity) sweeps the bottom …
In other words - there is likely no bad way compared to not changing the oil … Do what works for you …
I usually take the oil filter off, start the engine, when all the old oil is done spraying out, I shut the engine off, I proceed and put a new filter on.. I then wash everything off.. I like to keep things exciting.. 
less chance of rounding off the drain plug.. LMAO 
less chance of rounding off the drain plug.. LMAO 
dnewton3
Staff member
We're into our third page of this topic, and the conclusion is?
There is no consensus.
As if anything was going to be different in this thread from those 22 other threads with their many multiples of pages?
There is no consensus.
As if anything was going to be different in this thread from those 22 other threads with their many multiples of pages?
Kschachn said:
I drive the car to my shop, about 20 minutes of run time, put the car on the lift - pull the plug/open the valve. It’s still warm, freshly mixed, and drains quickly. I haven’t wasted either gas or time to warm it up, it already is warm.
Nearly every shop is changing it warm, right? The customer pulls in, having driven there, then the car is pulled into the service bay, lifted, and the oil drained and refilled.
The only people changing it cold are DIY. Not enough data to support that being better. Do whatever is more convenient.
But I have to say, that leaving the drain plug out overnight, to get all the last few drips is crazy OCD. When it slows to dripping, you’re good.
Nearly every shop is changing it warm, right? The customer pulls in, having driven there, then the car is pulled into the service bay, lifted, and the oil drained and refilled.
The only people changing it cold are DIY. Not enough data to support that being better. Do whatever is more convenient.
But I have to say, that leaving the drain plug out overnight, to get all the last few drips is crazy OCD. When it slows to dripping, you’re good.
I've always drained it immediately after driving home from work(half hour highway drive). I've done at least 8 different cars and never been burned or cared about the hot oil. It gets on my hand and is hot but it's never burned me, you all must have delicate hands
Who changes oil?
We got to the Moon almost 55 years ago....and you won't accept the "lifetime oil" claims?
We got to the Moon almost 55 years ago....and you won't accept the "lifetime oil" claims?
I was on a forum years years ago, which had a new members introduction page… when you would click on it to introduce yourself as new member a message came up to the effect of “no one care…” or something similar… maybe we need something like that, but it just says “nobody knows, please so don’t ask.”
Does extractor work on all cars? I tried to suck out some excess oil out of my Mazda and 6 mm OD tubing didn't fit.
Well, we know the 6 mm OD tubing doesn’t fit in your Mazda for one…
I drain it warm (100-140°F) after a drive. I'll pull the plug and filter then leave them to drip for 0.5-1 hour while I work on something else. I collect samples about midway through the drain, right as it starts to slow down. Then I'll put in the plug, spin on the new filter, and pour in the new oil.
No. It owuldn't work on my friends 2002 Silverado, for example.
If the pump is in pressure relief, it's already built pressure on the output side, which means the oil is flowing in the oiling system. What you describe might be an issue if someone changed oil in below zero conditions, and the oil was also at below zero temperature. That combination might not allowing the pump to prime as easily since the sump and probably also the pickup tube was drained of oil. A cold start without an oil drain wouldn't allow the pickup tube to drain and not cause any pump priming issues with super cold, thick oil.
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If the oil is drained cold, all the oil when it was last hot has drained down into the sump as much as possible. So draining the sump cold and letting it drain a long time - until is stops dripping, or let it drain hours or over night - will get just as much oil out of the engine. Draining the oil when warm/hot just reduces the time the oil has to drain. I change oil warm/hot most of the time, but I have changed a few vehicles cold when I could let it drain over night.
If there is stuff in the oil that's not filtered out by the oil filter, and will fall out of suspension, then it will settle in the pan every time the engine is shut off and it sits over night. Will that stuff mix back up into suspension the next time the engine is ran? Maybe, maybe not. If not, it won't ever come out of the pan with a hot or cold oil change.
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