Transaxle (or engine) oil change surface exposed unprotected if not driving soon after?

[2009Prius]

Just did the first 5K oil change and was going to do transaxle fluid change (yes it is way too early but I am curious to add an early data point to Bob Wilson's file) when this question came up.

Someone says that after oil change it is best to drive (or start engine) right away to coat the supposedly exposed and unprotected surfaces with new oil.

Is this true?

If so does the same apply to the transaxle fluid? <-- This is the main concern of mine, not the engine oil change. Thanks!

My own thought was that there is little difference between parking the car for two weeks (without oil change) and not turning it on until two weeks after an oil change. So it may not be critical to run the car right away after fluid change?

[Patrick Wong]

It's not necessary to run the car right away after changing either fluid, except for purposes of making sure that you did the job right and there are no leaks. You might forget to do this check if you let some time elapse. Another household member might jump into the car and zoom off.

[dogfriend]

Originally Posted by 2009Prius

My own thought was that there is little difference between parking the car for two weeks (without oil change) and not turning it on until two weeks after an oil change. So it may not be critical to run the car right away after fluid change?

Yes, I think that you may be obsessing a bit over this. I don't think it makes any measurable difference to the life of the engine whether you start right away or wait till the next day or even a few days later. You will never drain all of the oil (or transaxle fluid) in a normal change, there will always be a thin film of oil on the important surfaces. The only way this would not be the case is if you ran some kind of solvent through the engine to remove the oil film. (Don't do that BTW.)

[Patrick Wong]

Originally Posted by uart

... After an oil and filter change it can take several extra seconds for the oil circulate - I stand by that claim.

With the Classic and 2G Prius, the oil filter is mounted upright. If you partially fill the new filter with engine oil before installing it, then upon initial startup the engine will run nicely. If you don't fill the oil filter, then upon initial startup the engine will make funny noises for a few seconds until the oil pressure builds up.

[uart]

Thanks Patrick. I've worked with similar systems and know the drill. I always try to fill the filter as much as possible in these cases, though not everyone does this properly (or does it at all). Since you might get a longer delay in oil circulation then start the engine to get the oil system primed and circulating as soon as possible – while warm and the engine friction low. That's all I suggested and I don’t really see why it is so controversial.

[TonyPSchaefer]

I thinned out the thread a little. Reason? Because PriusChat is a place where people can ask any question or initiate a discussion about the Prius with absolute impunity. If anyone can not answer a simple question or inquiry without the necessity to act smug and superior, if you can not address the topic without attacking the person, if you grow tired of hearing the same question several times over, then this site is better off without you.

[philobeddoe]

the engine is not necessarily warm upon restarting after an oil change

i typically allow the motor to drain for quite some time, with the oil fill cap off, dipstick out, filter off and drain plug off, completely depressurizing the system, and allowing for ALL the used oil and residue to drain

the car has cooled 100% by the time the draining is complete

however, when refilling the oil, you are pouring the oil into the head, and it is draining down through the valve train and motor into the pan, and you are essentially manually lubricating from the top end down to the bottom

immediately after refilling the oil, there is probably more oil in the top end and coating the cams/crank as there would be before any start-up

... this manual pre-lubing is another good reason to start-up immediately after the oil change, in addition to checking for leaks/pressure

even if you pre-fill the oil filter, you're not affecting the oil pressure on start up, and pre-filling the filter is not required, nor would it be considered priming

... as you're not priming the oil pump

the circulating oil is coming from the pan, going from the pick-up to the pump and then the circulated through the motor

this is the second virtually identical thread regarding 2009Prius's oil change ... it's looking like more of a hang-up than a lubrication question

[uart]

Originally Posted by philobeddoe

the engine is not necessarily warm upon restarting after an oil change

i typically allow the motor to drain for quite some time, with the oil fill cap off, dipstick out, filter off and drain plug off, completely depressurizing the system, and allowing for ALL the used oil and residue to drain

the car has cooled 100% by the time the draining is complete

however, when refilling the oil, you are pouring the oil into the head, and it is draining down through the valve train and motor into the pan, and you are essentially manually lubricating from the top end down to the bottom

immediately after refilling the oil, there is probably more oil in the top end and coating the cams/crank as there would be before any start-up

... this manual pre-lubing is another good reason to start-up immediately after the oil change, in addition to checking for leaks/pressure

even if you pre-fill the oil filter, you're not affecting the oil pressure on start up, and pre-filling the filter is not required, nor would it be considered priming

... as you're not priming the oil pump

the circulating oil is coming from the pan, going from the pick-up to the pump and then the circulated through the motor

this is the second virtually identical thread regarding 2009Prius's oil change ... it's looking like more of a hang-up than a lubrication question

I advised the OP in the other thread that he'd get better lubrication if he started the engine immediately after the oil change. I don't know why he needed to start another thread to debate it. Several people criticized my suggestion but others (including yourself have confirmed it). You’ve just included one more reason.

Personally I like to do the oil change when the motor is still a bit warm and aren't too concerned about getting every last bit of the old oil out (I warm drain for about 5 minutes with the oil filler cap removed). I know that some folk do like to do it longer and try to get as much of the old out as possible, that’s cool too, but hopefully you can admit that its just as much a "hang-up" as my "cold start the next day without oil system being primed" hangup.

[philobeddoe]

Originally Posted by uart

I advised the OP in the other thread that he'd get better lubrication if he started the engine immediately after the oil change. I don't know why he needed to start another thread to debate it. Several people criticized my suggestion but others (including yourself have confirmed it). You’ve just included one more reason.

Personally I like to do the oil change when the motor is still a bit warm and aren't too concerned about getting every last bit of the old oil out (I warm drain for about 5 minutes with the oil filler cap removed). I know that some folk do like to do it longer and try to get as much of the old out as possible, that’s cool too, but hopefully you can admit that its just as much a "hang-up" as my "cold start the next day without oil system being primed" hangup.

i'm not criticizing you

when i begin my oil change, the engine is warm
by the time she's topped off and ready to roll, she's cool.

when i check the fluid levels, she's warm again.

i'm addressing the need to prime a Prius

further, even on the old Fords, you didn't need to prime 'em after an oil change, you primed 'em after an engine rebuild



2009Prius can start the car or not start the car ... it just doesn't matter

YouTube - Meatballs - It Just Doesn't Matter

YouTube - Meatballs - It Just Doesn't Matter

[2009Prius]

Thanks to Tony for keeping this forum newbie friendly!

I did not mean to start an identical thread. The original thread was on a stuck drain gasket and then it diverged to the question of starting time after oil change.

Since I have done the engine oil change already and whatever damage I may or may not have done has come and gone. My main concern now is the transaxle fluid change, which I am going to do the next. Thus this thread.

Unfortunately I haven't seen nearly as detailed discussion for transaxle as that for the engine.

Maybe I should remove the "(or engin)" from the title but I don't think I have the authority to do it.

I just went back to the first post and added some comments. Hope it will help.