Drain oil, hot or cold?

[Sully2]

the hotter the better, the fact that there is any question on this surprises me.

The "fact" that someone really believes THAT suprises me!!

 

[SteveInMD]

I like the idea of putting it to the test...Run the motor until the oil is hot. Then drain just enough to take a sample and re-insert the plug. Now let the oil cool and settle overnight. The next day drain the rest and sample it. Send both samples the Blackstone labs.

If it really makes any difference, the hot sample should be dirtier than the first. If they are the same, it makes no difference hot or cold.

I think this test is the only way this thread will go anywhere.

 

[markct]

I say again, if yall have that much crud runnning around your engine that the filter isn't catching...or even that much crud in the first place....then 1) make sure you have an air filter, 2) make sure your engine oil fill caps are in place. Cause something ain't right.

well some of my engines may likely have that much crud running around them, i dont buy everything brand new, infact most anything with an engine i havent bought brand new so it may likely have crud in it, might as well flush out as much as possible.

 

[PineRidge]

Can someone point me to a set of on-line directions for changing oil that says to do it cold? I see lots that say warm or hot but I have yet to see the words cold engine.

I am really interested. And for every URL that you supply telling us to change the engine oil while cold, we'll be more than happy to furnish 3 URLs that say to do it warm or hot.

 

[klm]

Or show us a service manual from any manufacture that says drain it cold.

 

[Doc_Bob]

Or show us a service manual from any manufacture that says drain it cold.

Well, I looked. I cannot find any that say do it cold. I did find a 2003 NH TN70A manual that does not care. No mention of hot or cold. My 2002 Volvo S60 does not care either. Now, my 1993 Ingersoll lawn Tractor wants it "thoroughly warm". What does "thoroughly warm" mean ?

But, the Ingersoll suggests straight weight, 30 or 40 or 50W. When cold, that stuff is like molasses. The newer machines (Volvo and NH TN70A) always want me to use multi-viscosity oils. Now, 5-30W, 10-30W and 15-40W which run like water at ambient temp in the summer from 40 to 100 deg Fahrenheit. I can understand why the single weight oil in my Ingersoll (if I used 30 or 40W, I don't, I use 15-40W) might need to be "thoroughly warm", but multi viscosity clearly does not need to be hot or even "thoroughly warm".

I cannot find anyone who says "cold". But it raises the question that I had not previously asked, what do folks mean by cold or hot? Or "thoroughly warm"? Ingersoll does not define it. Ingersoll does not say drain when hot, so does the fact that they do not say "hot" mean I should not drain it when "hot", only when "thoroughly warm"?


Now, my air cooled 2004 4.5 HP BnS motor says the oil should be "warm" to drain it. They allow single vis oils. Are they making sure the single vis oil can drain out by requiring it to be "warm". Note, the manual does not says "hot".


Then, let’s talk about synthetic oils at 0 degrees Fahrenheit. They run like water when "cold", just like a good 30W single vis oil would when "hot".

Do the newer machines, raised and engineered on multivis oils, no longer mention to drain oil when "hot" or 'thoroughly warm" (or cold) because multivis oils have made "hot" irrelevant? Is draining oil "hot" a hold over from single vis days?
Bob

 

[PineRidge]

Well, I looked. I cannot find any that say do it cold. I did find a 2003 NH TN70A manual that does not care. No mention of hot or cold. My 2002 Volvo S60 does not care either. Now, my 1993 Ingersoll lawn Tractor wants it "thoroughly warm". What does "thoroughly warm" mean ?

Bob

Bob I would imagine (just an educated guess here) that just because they don't specify hot or cold in the manual that doesn't mean that they condone it be done cold. I recommend that you write New Holland and ask them your questions directly. I'll wager with you what they recommend.

I searched the Internet myself for a set of instructions that mention changing engine oil with a cold engine and I could find none. That doesn't mean that those instructions don't exist, but it does mean that the biggest majority recommends that the engine not be cold.

However you and those here that feel the need to change the engine oil while stone cold are most welcome to continue to do so, it's certainly a personal choice.

I was always taught to drain engine oil hot or when throughly warm and I will continue to do so also.

 

[RobJ]

....and get oil on the bearing faces as others stated.

Now just what does this mean? Get oil on the bearing faces? I mean if you fill from the side of then engine like my Kubota, the oil pretty much goes directly into the pan. On my truck it's via the front of the valve cover. Probably down the front of the timing gears and into the pan. I don't see it hitting a lot of stuff. Please explain.

 

[RobJ]

Bob I would imagine (just an educated guess here) that just because they don't specify hot or cold in the manual that doesn't mean that they condone it be done cold.

Or hot either. I did a few searches and found that most did say drain warm. But the reason was to speed the oil draining process. So sort of a hit and miss. A couple added that adding new oil to a warm engine sort of preheated the oil for the next start. Didn't mention that maybe you put the oil in but not start until the next morning. But I did find some about the particles flushing out, but these were forums with input like what we have here. Some had even the same points made here, if you warm the oil by running, you mix the particles, but then you spray them around your engine sticking to everything. Then if you only drain your oil for 15 minutes you still have a lot of oil and particles clinging to parts inside the engine. Good point? Bad point? One poster I found said he had let the engine sit overnight, then heated the pan with a heater, then drained the oil. So all the oil is drained down from the engine, then heated to get all the particles out. Best of both worlds? Maybe heat your engine, then let it drain all night.

This is interesting reading i must say.

Rob

 

[RobJ]

well some of my engines may likely have that much crud running around them, i dont buy everything brand new, infact most anything with an engine i havent bought brand new so it may likely have crud in it, might as well flush out as much as possible.

Hey same here Mark. I can't afford new stuff, my 1999 L2500 had about 1200 hours on it when I bought it. But if it's been maintained properly I bet you are ok. Heck on my L I bet I could pull the pan in about 10 minutes. Wonder what I would find. Some sludge perhaps if my previous owner didn't do proper PM. But if it's that thick clay type sludge I mentioned earlier, that stuff doesn't remix with the oil anyway. Trust me, if it did my oil would turn black after an hour of running. With about 50 hours on my used tractor since I got it (about August 2005), it still looks like it came out of the can.

Maybe one weekend I'll yank the pan for a look.

OK I'm going to lurk for a while, just getting caught up from the long weekend! Hope everyone had a good one.