1/4 qt flush when draining oil?
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Patman
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I pour more than one quart of fresh oil in my Corvette at the end of the oil change, because the design of my oil pan leaves 1/2 quart of oil in the back of the pan with the car up on ramps. So by pouring in a lot of new oil I hope to flush out a bit more of that trapped oil.
Its a good idea. I put the plug back in lightly and after pouring the oil in wait about 10 minutes. Then I remove the plug. I feel that way I get a second better flush that repoves extra residu of the entire bottom of the pan. Probably a wast of time..but that's me
I do that too if I have an extra quart lying around.
Sounds kinda wasteful considering that the old oil is still in the lifters, oil passages, oil pump, etc. I doubt it would do much if any good. If there's sludge in the engine an extra bit of oil won't wash it out.
[ March 09, 2005, 09:43 AM: Message edited by: paker ]
[ March 09, 2005, 09:43 AM: Message edited by: paker ]
A half quart left in the engine on a 5 quart system is ten percent. On a 5000 mile OCI that represents 500 miles into the OCI. So we spend 90 percent of our driving time with dirtier oil than what you will have if you can get that last half quart out. It does not seem significant to me. But I do understand the desire to "purge" the system of the old dirty oil. It is just a complusion with us BIOTG oil freaks.
By pouring in a small amount of "rinse" oil after draining, might that oil simply pool around the lower, front portion of that particular head and drain down the nearest channels? Much like attempting to "rinse" an entire bathtub by pouring a bit of water along the back-left corner of it?
One will never drain all the dirty oil out of an engine unless he dismantles it, so by definition, it comes down to an acceptable percentage of dirty oil mixed in with the new oil. What I see on the dipstick after an oil change is more than close enough to "honey color" to make me perfectly comfortable with forgoing "rinsing," which seems a flawed idea anyway, based on the above questions.
One will never drain all the dirty oil out of an engine unless he dismantles it, so by definition, it comes down to an acceptable percentage of dirty oil mixed in with the new oil. What I see on the dipstick after an oil change is more than close enough to "honey color" to make me perfectly comfortable with forgoing "rinsing," which seems a flawed idea anyway, based on the above questions.
Well, I disagree with the Naysayers. You rinse old oil off of the cam/rocker area, the oil return gallery, and the bottom of the pan. Total cost..less than a buck. Mental satisfaction (for me) Priceless
Why not get completely bonkers and fill the crankcase with supertech(or any other cheap oil in a 5 gallon jug) and 15 oz of LC or neutra after the first drain and run the engine for 15 minutes, drain and fill with the good oil??
I have never done this but would consider it if I thought it did any good.
I have never done this but would consider it if I thought it did any good.
Both SAE and Mobil indicate a full dino flush before a synth changeover. If using a dino oil again, there is little point unless it is some old used car. Better to spend the extra few dollars and refill it all the way, then run the car with clean rinse oil and old filter for at least a week to suspend as much crap as possible in the rinse oil. I do this with ARX after treating it, I rinse with cheap dino & old filter for a week-month before final rinse with fresh filter. I do all this stuff with my oil extractor...really easy.
[ March 09, 2005, 11:10 PM: Message edited by: Audi Junkie ]
[ March 09, 2005, 11:10 PM: Message edited by: Audi Junkie ]
This is true, a 1 second pour into the oil fill should be enough.quote:
Originally posted by TooSlick:
This is like trying to wash a car by dumping a bucket of soapy water over the roof and not rinsing it. But if it makes you feel good, knock yourself out.
Vette-brother, You should at least jack the rear of the car to level or best would be to raise the rear higher to get that old oil out. Mine takes 7 qts to get to the full line when I get the rear up higher then the front.
I drained with the front on ramps and the rear on the ground. Waited for the oil to stop.
Placed a jar ontop of my enclosed oil pan. Jack rear to even with the front and got 1/2 qt more out. Waited for oil to just about stop draining.
Jacked rear higher then front and almost finished filling the quart jar.
So its possible that you may be leaving an entire quart of old oil in your car.
How many quarts does it take for you to be on the full line?
Sorry to highjack your thread pmwalter.
Patman
Staff member
I'm not into the whole "jacking up the rear" thing. Sorry, just too dangerous for me. Plus my big jack is at my parent's house, I don't have room for it here.quote:
Originally posted by silverz06vette:
Vette-brother, You should at least jack the rear of the car to level or best would be to raise the rear higher to get that old oil out. Mine takes 7 qts to get to the full line when I get the rear up higher then the front.
I drained with the front on ramps and the rear on the ground. Waited for the oil to stop.
Placed a jar ontop of my enclosed oil pan. Jack rear to even with the front and got 1/2 qt more out. Waited for oil to just about stop draining.
Jacked rear higher then front and almost finished filling the quart jar.
So its possible that you may be leaving an entire quart of old oil in your car.
How many quarts does it take for you to be on the full line?
Sorry to highjack your thread pmwalter.
I think it takes me about 6.5L to show full on the stick, although I'm not 100% sure since I just shove in an even 7L to keep it simple. That puts the level above the full mark (but as you know, the LS1/LS6 can handle being overfilled)
I haven't measured but when I pull the oil filter while the drain plug is out, a little more drains out.
I agree if you have some extra, clean oil laying about, this probably helps in some tiny way. I don't do it all the time, but yes I have poured a 1/2 qt in just to see how fast I collect the exact 1/2 qt and how clean it appears (worth the effort just to see)....
In some cars it's (that 1/2 qt collected) amazingly clean (even though the old oil was pretty dark) - this would sorta tell me that this practice as a rinse is useless. OTOH on some engines the 1/2 qt oil comes out looking like long used oil.....hey, guess what, not a bad idea!
So the usual answer on BiTOG - it depends!
In some cars it's (that 1/2 qt collected) amazingly clean (even though the old oil was pretty dark) - this would sorta tell me that this practice as a rinse is useless. OTOH on some engines the 1/2 qt oil comes out looking like long used oil.....hey, guess what, not a bad idea!
So the usual answer on BiTOG - it depends!
Consider how little 1/4-1/2 quart really is and how much flushing it can really do. I bet it reachs like 10% saturation, maybe 25% at the very most. That equates to very small amounts of contaminates washed out. The only way, imo, is a full re-fill of rinse oil for a few days of running (reaching 99% saturation). The other option would be a 1-2 quart fill and you crank the car without spark. That way the oil gets pushed up and around...50% or more saturation if you are lucky and this is only part of 1 or 2 quarts compared to a full refill flush/rinse. Either one will do much more than a "gravity" rinse. Flushing has it's place, but in a operating engine, at temp.
I never drain mine off after the track overfill. Like you said its not going to hurt anything.quote:
Originally posted by Patman:
I'm not into the whole "jacking up the rear" thing. Sorry, just too dangerous for me. Plus my big jack is at my parent's house, I don't have room for it here.quote:
Originally posted by silverz06vette:
Vette-brother, You should at least jack the rear of the car to level or best would be to raise the rear higher to get that old oil out. Mine takes 7 qts to get to the full line when I get the rear up higher then the front.
I drained with the front on ramps and the rear on the ground. Waited for the oil to stop.
Placed a jar ontop of my enclosed oil pan. Jack rear to even with the front and got 1/2 qt more out. Waited for oil to just about stop draining.
Jacked rear higher then front and almost finished filling the quart jar.
So its possible that you may be leaving an entire quart of old oil in your car.
How many quarts does it take for you to be on the full line?
Sorry to highjack your thread pmwalter.
I think it takes me about 6.5L to show full on the stick, although I'm not 100% sure since I just shove in an even 7L to keep it simple. That puts the level above the full mark (but as you know, the LS1/LS6 can handle being overfilled)
Patman
Staff member
Yep, that overfilling definitely seems to be doing no harm according to my UOAs. And my engine doesn't burn any oil at all (not noticeable on the dipstick anyhow) so the overfill is not being burned off like it would in some engines.
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