Drain oil, hot or cold?

[Sully2]

A differential doesn't have a filter to take those out like an engine does. I have magnets on all my ATV's and I barely get anything on them. Just a little smudge of stuff. If there are heavy chips floating around then you probably are about to have bigger problems.

Really go to a shop that rebuilts engines and ask around. Any well maintained engine I rebuilt didn't have any sludge (basically dirt, carbon, etc) in the pan. But ones that didn't get regular PM would have a nice thick layer of this stuff. It would sort of feel like wet clay sticking together, dry in the middle, I could get it out in chunks. And believe me, once this stuff formed, hot oil did not break it down when the engine was running. Worst I've seen is when I took off the valve cover, you couldn't see the springs. It was caked in that bad.

LOL..guess I should have read ALL the replys first...lol

 

[Dargo]

But dont forget...the rear end isnt "force lubricated" and has "no filter" either!!! If you have any lube supply that is filtered...LMAO..even with an infamous FRAM filter...and your seeing that sort of stuff in your oil...then the filter has no "guts" in it and is nothing more than a metal can...

Also, don't forget to never shut your engine off either. If you do, no matter what you will not have oil up on the top of your bearings and well circulated on all surfaces when you next start it up cold.

 

[jeffmazz]

DOC BOB,

I always drain my oil when the engine is stone cold. I have a 4WD Toyota P/U with 287,000 miles on it that has always had the oil changed (every 5000 miles) when the engine was cold. No major engine failure yet...never had to open the engine for anything. I do the same for any lubricated component (transfer case, differential, etc.) Never had any problems.

I began draining cold when I noticed my motorcycle oil was always getting dirty fast after a fresh oil change (hot engine). I drag race a Yamaha V-Max and slipping the clutch to get out of the hole turns the oil dirty in a hurry. I thought why not drain the oil after sitting overnight so all the crap in the oil can settle to the bottom of the pan? The oil definately takes much longer to show dirty in the sight window using the cold drain method. I had to replace the oil pan a few months ago and it was as clean inside as the day it was made....so I don't know wether the "build up of sludge in the pan draining cold oil" theory holds any water. I will know better if and when I have to pull the pan on my Toyota.

Welcome to the cold drain club.

Jeff

 

[zeuspaul]

I drain warm or cold as I don't want to burn my fingers. However I always pour a little clean oil through the system before I replace the plug to help *rinse out* some of the remaining dirty oil.

Zeuspaul

 

[kenmac]

I just drained my oil to send off for test. Per the oil sample instructions , it states to drain the oil hot.

 

[Doc_Bob]

I just drained my oil to send off for test. Per the oil sample instructions , it states to drain the oil hot.

Wouldn't it be interesting to drain one hot and one cold, then compare?????
Bob

 

[cp1969]

Cold. You will get the most old oil out of the engine this way. I could never find any advantage, either to the engine or me, of draining hot.

 

[markct]

Cold. You will get the most old oil out of the engine this way. I could never find any advantage, either to the engine or me, of draining hot.

how do ya figure??? the only thing that i dont mind draining cold is auto trannys since you have to drop the pan anyhow to change the filter so it all gets cleaned out either way. but i can tell you that if your do one cold and leave a container under it overnight with the pan off it will drip out alot more than one that ya did hot, naturaly more thick oil would stick to the parts than thin oil as in hot oil. i do agree that the oil doesnt need to be super hot like some people say, but i do feel that it should be atleast circulated as to help get the bits of crud that acumulate on the bottom of the pan into suspension. i like about warm to the touch, where ya can still handle the drain plug, but not stone cold by anymeans, but thats just me. i do feel tho that stirring up the oil is the important part more so than the heat. in reference to auto trannys, in the case of allison automatics those are a different case altogether since the pan doesnt need to be dropped to put in new filters so i do make sure the oil is atleast warm before draining, not neccesarily hot but warm. i always wear thin nitrile gloves when i change oil and it not only keeps all the bad stuff in oil of your skin but it also helps a little with the heat transfer to your skin

 

[Doc_Bob]

i always wear thin nitrile gloves when i change oil and it not only keeps all the bad stuff in oil of your skin

I always wear gloves to keep the oil out of my system. Same thing with all fluids. Until I start using used oil or antifreeze as hand loation, I just wear gloves.
Bob

 

[PineRidge]

I always wear gloves to keep the oil out of my system. Same thing with all fluids. Until I start using used oil or antifreeze as hand loation, I just wear gloves.
Bob

Let's see a Doctor wearing latex gloves, I would expect nothing less.

I found out a long time ago that if you take some unused grease and work a little into your hands it will not only keep your hands soft but when you go to wash them all the crud comes off.