Originally Posted by demarpaint
Originally Posted by Bill7
Sorry, I am missing the context of this. The current discussion is whether doing an engine flush, then drain the oil/solvents out, and then add new oil still leaves a small amount of the solvents from the flush in the engine mixed with the new oil, which over the next 5,000 miles will harm the engine.
Are you saying a 2nd oil change a few miles later would be required to get the remaining solvents out?
That would depend on how much oil remains after the drain plug goes back in, and the sump gets filled with fresh oil. It would vary between vehicles and how long the oil was allowed to drain, how hot the oil was when it was drained, etc. Quick lube places don't spend much time allowing oil to drain. Bottom line if you want all the flush out, it might not be a bad idea to refill the sump with fresh cheap oil, a cheap filter, drive a few miles and dump that, and change the filter. OCD behavior, some people might say. Now you'll have residual cheap oil remaining, to mix in with the preferred oil.
Originally Posted by demarpaint
Originally Posted by Bill7
Sorry, I am missing the context of this. The current discussion is whether doing an engine flush, then drain the oil/solvents out, and then add new oil still leaves a small amount of the solvents from the flush in the engine mixed with the new oil, which over the next 5,000 miles will harm the engine.
Are you saying a 2nd oil change a few miles later would be required to get the remaining solvents out?
That would depend on how much oil remains after the drain plug goes back in, and the sump gets filled with fresh oil. It would vary between vehicles and how long the oil was allowed to drain, how hot the oil was when it was drained, etc. Quick lube places don't spend much time allowing oil to drain. Bottom line if you want all the flush out, it might not be a bad idea to refill the sump with fresh cheap oil, a cheap filter, drive a few miles and dump that, and change the filter. OCD behavior, some people might say. Now you'll have residual cheap oil remaining, to mix in with the preferred oil.
Just to add to the above comment. One does not need to recycle or waste the new flushed oil. It could be used in lawn/garden equipment, or used in another older vehicle, such as a grocery-getter, low use work/farm truck. My last full flush, which is Amsoil OE with 10% used oil, will be going into my daughters, 2004 Saturn with 200K miles. We only paid $1K and it has been a reliable car for 3 years getting her to school and back.