Partial oil change?

[fuel tanker man]

Having looked over the info regarding old oil being able to protect better than fresh oil (a severely debatable point, I realize)...

I just wonder, assuming that the old oil argument is correct... I wonder if you could get the best of both worlds by doing a partial oil change?

In a 5 quart engine, you could pump two or three quarts out through the dipstick tube, and replace them.

Then change the oil filter at the next interval, and maybe pump out and replace 2 quarts...

I thought of this because in my 1993 Ford Escort's earlier years, it was burning about a quart of oil every 1000 miles. Therefore, I figured I was getting an oil change every 4000 miles or so just by topping off the burned oil.

But that was pre-AutoRX for my car, and now at over 225,000 miles it really isn't burning any significant amount of oil, so I'm doing regular oil changes at 4000 to 5000 miles.

My point being that engine really lasted a long time on pretty much no oil changes at all (pre-BITOG days) So the used oil idea seems plausible to me. If used oil didn't work well, my little Escort would have escorted its last about 100,000 miles ago...

Advantages... you wouldn't have to put the car on ramps and get under it (except to change your oil filter as needed, and a good filter ought to last for 10,000 miles or more (based on the extended drains we see here in the UOAs).

Just a thought...

Dan

 

[cjhepburn]

I religiously changed the oil in my original owner '86 Escort GT with an OCI of 3000 miles (Castrol 10w30). That car was a piece of cr ap and left me stranded far away from home 4 times in it's life. It started using about a quart between changes after 110k. Even though I took very good care of it, the engine failed at 158k (rings).
There might be something to your argument.

Edit: Really?... C.rap is a censored word.

 

[Captain_Klink]

bad news. my colt 1.5l has been getting religious oil changes every 3k for 15 years. it has 180k, uses no oil and runs perfect.
the difference being my engine is made in Japan, by the Japanese.

 

[ADFD1]

Originally Posted By: Captain_Klink
bad news. my colt 1.5l has been getting religious oil changes every 3k for 15 years. it has 180k, uses no oil and runs perfect.
the difference being my engine is made in Japan, by the Japanese.



My American Ford engines and family Ford engines are doing just fine, some are over 20 years old. Sometimes its just bad luck that takes an engine out early on, Japanese or American.

c3po has an American Chevy with close to 375,000 miles on it and still going strong IIRC. BTW I'm not a Chevy fan, but it appears they built some good engines in the past.

AD

 

[simple_gifts]

I'm curious which engines are made in Japan by others than the Japanese. 8)

 

[GMorg]

For those that don't know the old threads, the link below is the paper that really got me thinking. I find it hard to argue with data.

Link:
http://www.ornl.gov/~webworks/cppr/y2005/pres/117987.pdf

Oak Ridge National Labs manuscript

 

[lostwrench]

I got 301,000 miles out of my 1968 Pontiac LeMans engine. 350 cubic inches.

 

[cjhepburn]

Originally Posted By: Captain_Klink
bad news. my colt 1.5l has been getting religious oil changes every 3k for 15 years. it has 180k, uses no oil and runs perfect.
the difference being my engine is made in Japan, by the Japanese.

I think you're right. The quality of the engine probably has more to do with it than anything else. Ford has successfully converted me to Japanese cars.

 

[Gary Allan]

Find a place to hang a Frantz or Motor Guard somewhere. That would accomplish your goal. The cash outlay would be high, but you would be reduced to 1 quart every 3k or so. The sump takes about 2 years to fully mature.

 

[BearZDefect]

An ordinary oil change leaves a significant amount of used oil in there, often close to one quart, so the OEM has already given you the benefit of used oil.

 

[Gary Allan]

While most aren't going to go to the trouble (oil still too cheap), I don't really see a problem with the "phased" sump. It's what a few higher end performance cars have to do due to cached oil via coolers and thermostats.

 

[mechtech2]

No way is the oil left in an engine close to a qt.

 

[JohnBrowning]

Look at modern rotary engines UOA to see what happens when you can only easily change half the oil out!LOL The partial oil changes donot seem to be helping these wankles out at all!

 

[Gary Allan]

Well, if you halved the oil change interval on a Wankel ..would it help? I'm sure there's someone who changes it like underwear and still has issues.

 

[Ken2]

So remove a quart and replace a quart every thousand miles. Change the filter every 10k.

 

[JohnBrowning]

I like wankles just not the production models anything less then 3 rotors and their wasting my time!LOL I think the problem is their oil cooler circuit was designed by a moron must have been one of the Japanese kids that got C+'s in school not the A+ students that work for Toyota!!!LOL I think it would help if you did not have 3 or more quarts of oil oil in the circuit but I do not think that is the only problem!

I would rather run Extended oil changes with bypass filtration then try to drain only half of my oil out and refill etc.... That would to me be like wipeing half of your butt after you had a bowel movement but not the other half etc.....LOL

The reason we change oil is because it is either chemically spent as in it's additives are not working any longer or it is full of dirt and other stuff we do not want in their. If filtration is good and the additives are good or replenished then their is no need to change it willy nilly like we do.

I think the main problem for most is that they lack the additives they need to replenish and they lack fine enough bypass filtration to keep things in good order. I have a Trasko filter that I used on my Dodge that is fully flow screen and bypass all in one canister that screws in place of the OEM sized filter. I do not have anything that can use it currently so it just sits around. It worked great on my Dodge. I had an oil pressure guage and it never caused any issues at all. What I liked best was that the media it used was not plain toilet paper or paper towels. It was very similar but specifically designed for oil filtration it was thinner material that was wound far tighter then toilet paper and it was kiln dried it was almost brittle it was so dry. It was immune to channeling. It is truly is a well built piece of gear. Once I am out of oil filters I am going to remote mount it on my Camry and try once a year oil changes. I am not a huge fan of once a year oil changes with out some better filtrationt hen what is common to full flow filters. I am seriously woundering about Amsoils line of filters and if their level of filtering is really good enough for extended oil change intervals with out bypass filtration!

 

[engineer20]

is a partial oil change (remove 1 quart every 1000 miles) a good way to remove sludge and add some new oil, albeit not all new oil, and as a way to make a smooth transition from conventional to full synthetic? (start with 4 quarts conventional), after a month, add 1 quart synthetic, etc 4 times until the 4th month or 4000 miles later, you have all synthetic after pouring synthetic in a few times

 

[Nick1994]

You have 225,000 miles on an Escort? Well that's about the biggest achievement I've ever seen of a car lol

 

[stickybuns]

Originally Posted By: engineer20
is a partial oil change (remove 1 quart every 1000 miles) a good way to remove sludge and add some new oil, albeit not all new oil, and as a way to make a smooth transition from conventional to full synthetic? (start with 4 quarts conventional), after a month, add 1 quart synthetic, etc 4 times until the 4th month or 4000 miles later, you have all synthetic after pouring synthetic in a few times


There is no reason to make a transition from conventional to synthetic. There still just oil. Seal swell is the same between any. Yet, partial oil changes do make sense to replenish TBN to keep acids under control, and the other additives. Studies have shown that used oil has lower wear rates.

 

[artificialist]

Originally Posted By: Captain_Klink
bad news. my colt 1.5l has been getting religious oil changes every 3k for 15 years. it has 180k, uses no oil and runs perfect.
the difference being my engine is made in Japan, by the Japanese.

Try getting 180,000 miles from a Mazda RX-7 turbo, and you will see that having an engine designed and built by the Japanese doesn't determine engine lifespan.