Ever curious how much dirty oil stays behind when you get impatient watching the never ending drip drip drip from the open oil plug? I have occasionally let it drip overnight, to come back and see no oil drip, but wondering 🤔 was it worth it? Did it even amount to very much?

I've been annoyed by oil change shops putting that drain bolt back the very second that the draining oil went from a thin stream to a fast drip. Come on guys, your leaving dirty oil in my engine in your haste to get to the next rube, er... customer.

Here is some empirical evidence for you:


As I walked away with the crankcase dripping, I got the idea to stick a small container under, remembering maple syruping in upstate New York near the Canadian border near Lake Placid. One tree, known as "old faithful" would fill the little hanging tin pails 2-3 times every 24 hours.

I didn't get quite that much, but your looking at nearly 9 ounces of used oil in that Tupperware container. And what a wonderful place for it to be. I am doing my version of an engine flush. One that does not rely on chemicals, detergents, VOCs or distillates IN THE OIL. I think a flush has value, but I don't like the idea of leaving those sludge busting chemicals behind. I suppose you could "flush the flush" by running a super short oil change interval, but I have always gotten a feel good effect from the following.

1. Warm engine to operating temp.
2. After 20-30 minutes of cool down, drain oil, remove filter.
3. Fill engine with inexpensive oil, no seafoam, marvelous mysterious oil (transmission fluid) or any such harsh cleaners. Instead, you could do a top end intake cleaning now with the ones that insert the straw into the intake. These products DO get into the oil, in varying amounts, depending upon engine condition, but the oil won't be around very long anyway.
4. After 150-250 miles fully drain the oil again from a warm engine.
5. Fill with a quality synthetic (Mobile 1, Royal Purple, Amsoil are my goto brands, but to each their own.

I find that this method suspends a lot of contaminants in the cheap oil, but by NOT running it to where it becomes highly used does more to clean an engine in a safer (seemingly) way. How do I know it works well? I know because the quality oil that follows it stays clean, clear and golden on the dip stick for thousands of miles - and comes back from analysis better off than ANY other method I know of.

Some would observe that there is oil being "wasted" by dropping useful oil at only a few hundred miles. Perhaps. I tend to keep 5 quarts/liters and use it for lawnmowers and less critical (to me) use cases. Either way, I found this process when I could not get my preferred brand of oil for a newly purchased used car, and swapped it after a week when stock became available. 3k miles later, the changed oil was still golden. Unless my eyes were lying, I was obviously onto something, and it continues to work in this way.

Long drain cycle (overnight) and a super quick fill, suspend and drain procedure. Try it and see if you get similar outcomes.

 

I pay perfectly good money to have my car professionally serviced. <cough> <cough> I seem to have developed a cough.
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<serious> I was actually thinking about this the other day. With my portable generator! Should I change the oil, dipstick (cold) is clean-as? Ran it for a while, drained and the oil was worthy of putting back in the ground.
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<joke> I was thinking of changing the air in my air suspension. It never goes down so no-one ever changes it...oh never mind.
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P.S. I was gonna make a joke that one should really do 2 oil changes, but beggar me I read further and you actually do that!!! I envision, in 50 years, a barn-find X350 with all the computers and even the ali body air suspension brakes supercharger starter motor "rusted out", but a perfectly good engine!

The supposition is that some of the sludge at the bottom of the pan stays there. What have you to say about that? (meaning actual experience on engine life rather than mere supposition)

 

The local one-man band mechanic I used to use, (he retired !), always used to use an engine flush before draining the oil. I never found out what he used, but it seemed to work as the oil was always clean after refilling, and I never had any ill effects afterwards.

It was probably this stuff
https://www.eurocarparts.com/p/wynns...gaAsVtEALw_wcB
You put it in just before your oil change, i.e. you don't drive with it in, it is added about 15 minutes before, and the engine is then allowed to idle, then the oil is drained.

 

If you're DYI and so concerned, it's like why not drop and clean the oil pan?

 

I have. It was rather clean the time I did (to replace the gasket... but the image of the 9 ounces of dirty oil I posted would come out regardless of the cleanliness of the pan. The oil in the pic had 9745 miles on it. Another obsessive idea I attempted was to run 8 or 10 ounces of clean oil through the filler neck with the drain bolt out and filter off. No appreciable gain. I poured clean oil in, got clean out the drain, so I chalked that up to nothing ventured... nothing gained (or learned, except not to do that again.) I do like to try and empty the engine as much as possible, and I assume that while most of it is from the sump, some percentage is from oil passeges just running dry.

On any car that the filter screws upward, I fill the empty filter with clean oil before installing. It usually eliminates that 3 or 4 second nasty sound of an unlubricated engine on the first start after oil swap. Unfortunately the 4.2 liter AJ34 engine mounts the oil filter sideways. You would have to be pretty quick to install it without getting a mouthful of Royal Purple 5w30. And no, it is NOT grape flavored, by the way.