Changing the oil when cold

[ron in sc]

Changing oil cold ? Which means at ambient temp in garage of about 70 degrees.


I have always changed oil when hot but in this case I wonder if it's necessary or even advisable in this case.

Would it be better or at least ok to change oil hot or cold based on the facts outlined below. It would be easier for me to change it cold since it's already on lift.

Car has been on lift for 2 week waiting on a part and will be on lift at least another week. Plenty of time to drain down to lowest point.

The facts I considered
1-air cooled motor with dry sump
2-oil tank holds about 8 liter
3-engine holds less than 2 liters as there is a certain amount of oil in hoses and oil cooler in front of car.
4-car has two oil filters a large filter on thermostat housing at oil tank and a small oil filter on the engine.
5-oil is changed yearly regardless of miles, less than 250 miles put on car in last year
6-I will be using a new oil Motul 300V 15W50; previously using Mobil 1 15W50.
7-removed valve cover gasket to examine part of valvetrain and everything I observed appear clean and new, not even any brown staining. Car has about 15k miles on it.

[BMAN]

No I would wait until you can get it out and get it nice and hot then change it. I never change any of my vehicles oil without driving them and getting them nice and hot.

[porterdog]

IMO the oil doesn't need changing really, so changing it cold won't hurt. If it was me and I was determined to do an oil change I'd just let it drain overnight from both tank and sump and call it good.

[ron in sc]

Originally Posted by porterdog

IMO the oil doesn't need changing really, so changing it cold won't hurt. If it was me and I was determined to do an oil change I'd just let it drain overnight from both tank and sump and call it good.

That's what I did although it will continue to drain until I get my dual distributor back which is having the belt replaced due to the age of the car it's a 1997.

[earossi]

Hot versus cold means time. You are attempting to get as much old oil out of the engine as possible in a reasonable period of time. So, doing it hot, when oil viscosity is the lowest promotes faster draining. If you are doing it cold, be prepared to let the oil slowly drip out for a couple of hours. I doubt that there will be much difference in the volume drained cold or hot.....if you allow ample time for the draining.

If you think about it, all the engine parts drained their oil when you last shut off the engine. That "cold" oil is now lying in the engine sump and in the tank. And, there is some residual in all the hoses on the engine.

I don't know for certain, but guess that the difference in volume drained hot versus cold (over an extended drain time) would probably not fill a thimble!

Just my two cents.