Oil Change - Warm Engine or Cold Engine

[Jkay98]

Hibernation is over and its time to get the Cobra ready for the road.
Its been sitting in my garage on jack stands all winter and I plan to change the oil before I lower it.
My questions is do I try to drain the cold motor oil out which had lots of time to settle or do I let it run and warm up then drain it?
Either way I will probably let it drain/drip over night since I don't plan to take it out until this weekend.

 

[matth121]

warm it up- i do the same every spring

edit- if no ones told you or you don't know- 6L's and forget it- don't try to fill to full mark on stick- you'll get blow by back into your intake if you put the 7.5L's to get it to full

 

[EB85]

I always change it on a warm engine. Makes the drain process MUCH quicker and any dirt/debris/small children that have settled will be suspended in the oil versus sitting in the bottom of the pan.

 

[jrgoffin]

Makes no difference at all - just depends on how much you want to burn your hands. I've sent samples to BlackStone that were drained when both cold and hot and the results were identical. For the ease, I do mine all cold now.

 

[Jkay98]

Makes no difference at all - just depends on how much you want to burn your hands. I've sent samples to BlackStone that were drained when both cold and hot and the results were identical. For the ease, I do mine all cold now.

Thanks for the response. I will probably drain mine tonight and let it drip over night.
I still need to buy oil and a filter which I may just get the dealership since my friend works in parts.

 

[matth121]

I'd still have to think you're not going to get as much used oil out as you would when it's warmed. and if you're burning your hands, you're doing it wrong, lol, jk

 

[SlowSVT]

Best to drain it warm for 2 reasons

1) better to start a hot engine after an oil change

2) running the engine just before you drain it stirs-up the oil and will allow the fine particulate matter to be suspended in the oil rather than settled on the floor of the sump

 

[R.D.P.]

Best to drain it warm for 2 reasons

1) better to start a hot engine after an oil change

2) running the engine just before you drain it stirs-up the oil and will allow the fine particulate matter to be suspended in the oil rather than settled on the floor of the sump

2 I think is negligible, but you might have a point with 1. I used to always do warm but now do cold and let drip drain overnight.

 

[SlowSVT]

2 I think is negligible, but you might have a point with 1. I used to always do warm but now do cold and let drip drain overnight.

Keep in mind you want to flush the system as well as draining the oil. Small matter suspended in the oil will settle to the lowest point in the engine and that's not just in the sump. Running the motor and better yet, drive it around getting the oil to slosh around inside the engine which will pick-up that matter and suspend it in the oil. Pull the car into the garage bay and yank the drain plug while everything is still agitated. When you think about it it kinda makes sense. Replace the oil, pre-fill the oil filter which will flood the oil galleries quicker and your starting a hot engine which is better than a "cold start".

 

[SnakeBit]

I don't think it matters that much. Leaving the plug out and letting it drip overnight should allow most of the debris to slide down and out. Besides, if JR says it doesn't matter, that's good enough for me.

To me, a more important point is that the most engine damage occurs at startup, before oil pressure comes up.

How many pre-fill their oil filter BEFORE installing it? Your engine will run for a few seconds before the filter fills up and oil pressure comes up. Before jacking up the car, I fill the new oil filter to let it soak into the media. Then, just before installing it, I top it off and make sure the gasket gets lubed. Yeah, I know that the filter goes on horizontally, and a small amount will drip out before it is screwed in all the way, but it's minor. Still better than waiting for ⅓ qt to fill the filter.

After the crankcase has oil, I use a plain key cut for the car. Since there is no chip in the key, there will be no fuel nor spark. I turn the engine over a few times then stop, turn it over again for a few turns. That will get some oil flowing and since the engine hasn't started yet, any wear is minimal. Now use the transponder key and crank. Usually, my oil pressure comes right up. Now I check for leaks while the engine idles.

If I ever have to rebuild or change my engine, a Canton Accusump will be going on that boy. But in the meantime, I'm working on getting a remote setup for my filter. It will include a sampling valve in the line for sending off samples for analysis.

 

[Jkay98]

I ended up draining it cold but I get your point about stirring up the settled particulates.
I also pre-filled my filter although not all the way since these engine filters install horizontal, its hard to put on without losing some of the oil.
I ended up going with a Ford Racing Performance filter with Motorcraft 5w20 Full Synthetic.

 

[TheFleshRocket]

edit- if no ones told you or you don't know- 6L's and forget it- don't try to fill to full mark on stick- you'll get blow by back into your intake if you put the 7.5L's to get it to full

7 quarts puts mine at the full marker on the dipstick, and I've never had any oil-related issues.

 

[mr-proper]

I don't think it matters that much. Leaving the plug out and letting it drip overnight should allow most of the debris to slide down and out. Besides, if JR says it doesn't matter, that's good enough for me.

To me, a more important point is that the most engine damage occurs at startup, before oil pressure comes up.

How many pre-fill their oil filter BEFORE installing it? Your engine will run for a few seconds before the filter fills up and oil pressure comes up. Before jacking up the car, I fill the new oil filter to let it soak into the media. Then, just before installing it, I top it off and make sure the gasket gets lubed. Yeah, I know that the filter goes on horizontally, and a small amount will drip out before it is screwed in all the way, but it's minor. Still better than waiting for ⅓ qt to fill the filter.

After the crankcase has oil, I use a plain key cut for the car. Since there is no chip in the key, there will be no fuel nor spark. I turn the engine over a few times then stop, turn it over again for a few turns. That will get some oil flowing and since the engine hasn't started yet, any wear is minimal. Now use the transponder key and crank. Usually, my oil pressure comes right up. Now I check for leaks while the engine idles.

If I ever have to rebuild or change my engine, a Canton Accusump will be going on that boy. But in the meantime, I'm working on getting a remote setup for my filter. It will include a sampling valve in the line for sending off samples for analysis.

just push your pedal all the way down and then crank the car, need for plain cut key etc.
the car will cut fuel off and will just crank.
i do this every time i change the oil on my mach 1 to prime the oil filter.