Changing oil...Let it drain overnight ?

[Vette73]

I like to do basic stuff when it comes to my autos,brakes,tune ups,front end..

I'm going to change the oil on my 91 that I just got ...
I read in Corvette forums to let it drain overnight?

I know there is an oil cooler,if this is correct is that the reason?

Thank you....

[mike100]

The main reason for me personally is so that the oil filter doesn't blop out a bunch of oil on the front corner of the engine. The oil cooler won't drain since it is lower than the feed lines.

also define drain... I let it sit for a few hours before I pull the drain plug (and as mentioned, filter), but once that is done it is a 10 minute drain job. You will read about draining oil on a warm engine- I also feel you get a more complete draining, but really, just changing the oil without making a mess is all you need to do. If the oil is super bad, then you might consider running a cheap 10w-30 through it for 10 miles to flush, then come home, drain it and refill with the good stuff. If you have been keeping up with the maintenance regularly, then a simple 8-9 qt change is all you need- the oil cooler oil won't be that dirty anyhow if you change the oil like you are supposed to.

[XfireZ51]

I usually start the motor if its cold and warm up the oil but not hot. Then I'll use a floor jack to raise the passenger side of the car slightly. Remove the oil filler cap and undo the drain bolt. Let it sit overnight. I will also pour about
3/4L of oil into new filter before installing.

[Fully Vetted]

Originally Posted by mike100

The main reason for me personally is so that the oil filter doesn't blop out a bunch of oil on the front corner of the engine...

Doesn't the check valve in the filter prevent that from happening? Since I've had my car the oil change has always coincided with some kind of work being done so Corey has changed my oil both times.

Originally Posted by XfireZ51

...I will also pour about
3/4L of oil into new filter before installing...

That's always been a practice of mine as well.

[Kevin]

I let it drain till the flow coming out is a just a drop or two, hour or so wait, and I get ~10 quarts out

[Dynomite]

Originally Posted by mike100

The main reason for me personally is so that the oil filter doesn't blop out a bunch of oil on the front corner of the engine. The oil cooler won't drain since it is lower than the feed lines.

also define drain... I let it sit for a few hours before I pull the drain plug (and as mentioned, filter), but once that is done it is a 10 minute drain job. You will read about draining oil on a warm engine- I also feel you get a more complete draining, but really, just changing the oil without making a mess is all you need to do. If the oil is super bad, then you might consider running a cheap 10w-30 through it for 10 miles to flush, then come home, drain it and refill with the good stuff. If you have been keeping up with the maintenance regularly, then a simple 8-9 qt change is all you need- the oil cooler oil won't be that dirty anyhow if you change the oil like you are supposed to.

Concur

Let the engine sit over night so you can remove the oil filter without a mess as Mike suggests. Yes...some oil filters have a check valve of sorts but on Mobile 1 M1-207s the filter can be removed without any oil mess after sitting over night.

The LT5 engine and oil cooler will hold about 12 quarts of oil of which you drain about 8-9 quarts on an oil change.
So you get about 70 % of the old oil changed on an oil change. Next time you will get 70% of that 30% old old oil (9% of old old oil remaing), and on the third change you will get 70% of the 9% old old old oil remaining with 3% of old old old oil remaining. And so it goes

The oil pick up screen in the LT5 Oil Pan sits about 1/4 inch from the bottom of the pan (has nothing to do with changing oil ). When you drain oil (depending on how the ZR1 is sitting) you will have about 1/4 inch of oil in the bottom of the oil pan that does not drain.

On a ZR1 just purchased I will change oil twice within a week or so of each change to get down to the 9% of original "unknown" oil remaining.

LT5/ZR-1 Fluids

[A26B]

Originally Posted by XfireZ51

I usually start the motor if its cold and warm up the oil but not hot. Then I'll use a floor jack to raise the passenger side of the car slightly. Remove the oil filler cap and undo the drain bolt. Let it sit overnight. I will also pour about
3/4L of oil into new filter before installing.

This is my preferred method as well. While I do fill my conventional filters with oil, I have never done that with the LT5 upside down filter. Probably because I was leery about then flipping it upside down for the install & having a mess to cleanup.

Maybe lazy, but may also be because I looked into at least a dozen LT5's that had been stored by GM for at least 10 yrs. They were unceremoniously removed from the car and dropped into a crate or box, with whatever coolant didn't run out and oil still in the pan. I put an engine on a stand, drained the oil, turned it over & pulled the pan to remove rod caps for bearing/crank inspection. I was amazed to see that the bearings &crank had lots of oil on them after all those years.

Honestly, I have no concern about engine damage from starting with an empty filter. Synthetic oils are so much better than their fossil counterpart.

Please don't interpret this as disagreeing with filter pre-fill. You can't go wrong pre-filling the filter.

[mike100]

Originally Posted by Fully Vetted

Doesn't the check valve in the filter prevent that from happening? Since I've had my car the oil change has always coincided with some kind of work being done so Corey has changed my oil both times.

The rubber drain-back valve is only one side of the filter media. The big threaded hole in the center is wide open and whatever is seeping out of filter paper seems to back up on the filter pad if you try to pull it off right after you park it.

[Myt415]

Just let me know if you want Amsoil. I am a dealer/distributor and am able to help with all your lubrication needs.

[Paul Workman]

When the car has been driven before being shut off, say the day before, the oil will have drained back into the pan, as much as it will by the next morning.

So, lifting the front end enough to reach the plug and get a catch-pan under it, is about the best we can hope for. And, considering there is going to be at least a quart in the cooler anyway, there's no need to wait hours for the last drop to fall out - when the dripping slows to several seconds between drips - put the dang plug in and take it off the jack stands.

I pre-fill the filter, and with a little practice one can flip it over and place it onto the threaded post - in one quick motion, and usually not spill a drop. But, if you do, that's why God made rags!

I use the AMO 10W-40: buy it by the case from Marc Haibeck (fellow FBI member)