Cold engine oil change.

[Campverdefela]

I've always changed my oil as recommended by the manufacture allowing the engine to warm first, but is their any negatives to changing the oil in a warm garage, removing both drain plugs and filters and allow it to drain overnight without first warming the engine?

 

[watchman]

What I have heard...

The only thing I have ever heard was, if the oil has been sitting in the motor for a period of time, some of the contaminants that would be suspended in freshly circulated oil can settle to the bottom of places in the motor. The thought is that you will not get out all of the particulates that would have drained out if you had stirred it up by running the motor just before you pulled the plugs. How much you would leave behind may be microscopic or a matter of some science, but if you begin to figure out how many times a second a piston slides up and down in a cylinder at 6000 RPM, microscopic grinding media can have an effect over miles and time. But there is a reality to this. It is really not very often that you hear of a motor that died of oil related failure. Ride Safe!

 

[Campverdefela]

Here's someones opinion that I thought made sense....[TABLE="class: w100p"]
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Rapid Robert
Enthusiast | Posts: 328 | Joined: 01/06

Posted: 01/19/06
11:10 PM​

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[TD="class: pad, colspan: 2"] First off, if you drained out more oil than what is supposed to be in it including the oil filter then it was overfilled. Over filling is very bad thing to do, crankshaft will agitate oil causing air to be whipped in to oil which will cause less than adequite lubrication through out the engine. Never run engine below the add mark or over the full mark on the dip stick

Yes you can change oil on a cold engine. By cold meaning cool enough to touch the engine. Rememeber that the purpose of the oil filter is to trap dirt, not the oil pan. Oil pan serves only as a collection place for the oil to be pumped through the engine, it is not a dirt trap. If you have a lot of "silt" type dirt in the pan you are not changing the oil often enough and if its a high mileage engine you will have actually have extremly fine metal silt in it also. Thats why a magnetic drain plug in the oil pan is a good idea. Never change oil with out changing the filter, never! Asuming that you change your oil (non- synthetic) within 4 months or 4,000 miles which ever comes first, you should never have an oil related problem with your engine.Best non-synthetic oil is Penn.base oil such as Quaker state, Pennzoil, Wolfs Head, Amalie, Kendal and other marked as Pa. base crude oil. They have the highest level of parrafin base content which is an excellant lubricant.

Warm engine will cause the oil to flow slighty better out of pan but you trade off the extra time you will needed to get the oil that is on top of the engine to drain down to the pan and out of the engine.

Either way is OK because the little bit that stays behind , about 1/4 to 1/3 quart is not enough to be concerned with if you change oil and filter at the intervals listed abouve
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[NancysToy]

At least part of the advice to change engine oil warm is to allow it to be done more quickly, which is important if you are charging a customer labor for it. A technician who beats flat rate (the allotted time for a job) makes his shop money. I change oil cold from time to time, with no problems. You do have to drain it a while longer. I would not drain it overnight, just until it stops dripping appreciably. Some cold oil will probably remain behind, compared to draining a warm engine. The small oil passages and orifices don't drain the cold oil quite as well, at least with single viscosity oils. Multiple viscosity oils would not likely have as much problem in this area. Some oil always remains behind anyway, in a film on the lubicated surfaces, so there is always a bit of "contamination" from the old oil. The effects are negligible, especially in an engine with an oil filter. I wouldn't worry too much about changing the oil cold...but that's just me.