changing oil in cold engine

If you SHAKE that jug of new oil to get all those additives in suspension…

But you change the oil cold? You are sending us mixed signals, man!
 
I just plan my changes for when I get home from someplace I'm going to drive anyway. It doesn't require a big logistic support plan and driving around the block 3.24 times!
 
I always do drains when the engine is warm from recent use.
Sometimes warmer than others, but never cold.
I think that this allows for a more complete drain as well as more contaminants kept in suspension rather than left in the bottom of the sump.
Right or wrong, who knows?
 
Astro14 said:
As the oil cools, contaminants might precipitate out. A cold drain would leave them in the pan.

So, draining hot ensures that they are in suspension, and allows the oil to drain more quickly.
Click to expand...
I agree, except fully hot isn't needed. Very warm is ideal because contaminents are still suspended in oil, but oil isn't hot enough to cause serious burns. It's a good compromise.

My cousin changes my neighbor's oil soon after she gets home from work. Her engine and oil are very hot when she gets home. So he let's her car sit and cool with hood open for 15 min, then drains oil. The engine and oil are warm, but not hot when he changes oil and filter.

My car is seldom driven. So it's always cold when he comes to change my oil. So he takes my car for a 15-20 min drive (round trip) to warm up engine. Then he changes the oil. It's warm, but not hot.

If the OP wears rubber dish gloves, that keeps hands clean and protects from heat. He can buy an oil drain plug removal tool from Amazon that keeps his hands far from warm/hot oil. Loosen drainplug with a socket or box wrench, then remove it with tool seen below.

51HpMFqd2-L._AC_UF1000,1000_QL80_FMwebp_.webp
 
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If OP doesn't want to spend $20 on that special tool, dish gloves alone are good enough. Another good strategy is a socket with a 3 or 4 inch extention to keep fingers far away from warm/hot oil.
 
Astro14 said:
I don't see why the "flush" oil would pick up much at all. It goes straight from the head to the sump, while the trapped oil is in the galleries, the crank, oil pump, etc. all of which is completely isolated from the "flush".
Click to expand...
I agree. It might get some old oil off the bottom surface of the pan, but not much more. Not worth it to me, but All to their own...
 
I try to get best of both worlds. Drive home, directly up on Rhino Ramps, begin hot drain.

Go inside, eat lunch, watch a 30 min or hour long TV show, surf BITOG, etc.

Replace plug and refill. After an hour or so, I am confident I accomplished a very thorough drain .
 
O
gfh77665 said:
I agree. It might get some old oil off the bottom surface of the pan, but not much more. Not worth it to me, but All to their own...
Click to expand...
missed the point … in fact - hot thin oil does not suspend better - it can only agitate with circulation - but most oil sits in the pan if/when solids do drop out - and I was showing even then it does not matter …
(oil swept the pan - I don’t typically do this) …
That sample would also explain why when I put all 8 quarts in - oil was mint on the dipstick … done cold.
I’m not the one wasting time or getting burned …
 
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