Clean oil?

[cockblocker]

Ok so today I re-changed my oil...from 25w-50 to 10w-30. My car has 68k miles on it and that full day of driving it with the 25-50, when I drained it the oil was pretty much just as clean as when I put it in on Sunday. Now would you guys say that my internal are pretty clean, or was 20 miles not enough to get the new oil dirty?

[korbendallas68]

yeah, I KNOW my internals are filthy, and the oil stays clean for weeks.

[oleman]

Very little of the crude inside the normal engine will be disolved into the normal oil. That's good because the stuff would do damage to the friction surfaces of the engine if it got into the oil.
The crud does not hurt anything unless it gets so bad it stops up oil passages.
I once knew a man who faithfully ran 2 qts of engine flush through his SBC engine at every oil change. He would take off the tappet covers and show me his spotlessly clean engine. The top of the heads were perfectfully clean and he was very happy. At 50,000 miles it developed a rod knock and had trouble maintaining oil pressure. All his cleaning severely reduced the life of his engine.
The moral of this this story is to never use anything in an engine other than the recommend type and weight of oil.

[cockblocker]

Damn, then at what kind of interval would you run motor flush? I've heard stories where if you run some in an engine with over 100k miles...knowing that at that age it needs it, it's cause all sorts of leaks.

[Cliff8928]

Damn, then at what kind of interval would you run motor flush?

Never. As long as you follow the recommended intervals for oil changes and other maintenance, you should never have any need for any additives of any sort.




Cliff Scott
89 BerettaGT
04 AleroGX

[korbendallas68]

Whats a good internal cleaner? My internals are fully coated, I don't think the bitch who drove, and later crashed, her 2000 Grand Am ever changed the oil...

What would be a good cleaner to remove the tough build-up?

[smilinguy99]

I just sold a car I owned since new in 1996. I put 8800 miles on it in four years and two miles on it in the next five years.

It had four oil changes in the first four years and one oil change before the last five years began. So residual crud was not a problem.

All I did in the last five years was to start it up once in a while until it was warmed up, then shut it down. The two miles were accumulated in the following way: I drove from the lube shop and parked it.

The the oil was mostly clean, but it did get kind of what I'd describe as "sooty."

My $.02? I think cold startups do more to get the oil dirty than long warm runs or warm starts. Just my guess. Richer mixtures, less complete combustion, dirty, dirty, dirty.

sg99

[614streets]

Whats a good internal cleaner? My internals are fully coated, I don't think the bitch who drove, and later crashed, her 2000 Grand Am ever changed the oil...

What would be a good cleaner to remove the tough build-up?

There isnt really alot you can use to "clean" the inside of the engine only because most coked (said just like the drink) oil is "attached" and hard so only physical cleaning would remove all of the coke.

Even with that beng said you can pour over the counter engine flushes in it , some people even try kersosene.

With that done you can also run gm top cleaner through the intake or water from a spray bottle with the engine running above 2500 rpms.

[geoffinbc]

Run some tranny fluid with the oil. Or use Seafom.

[Juglenaut]

Oil should be changed regardless of miles used on it. So if you let it sit 3 months or better, the oil should be changed before any heavy commuting.

Ricer<opps (it is a typo, but funny) mixtures do dirty the oil faster. More carbon drops out of a poorly burnt rich mixture.

Don't freak on me now, but since my car was a project car so to speak I dumped 30% (no caster) nitro methane at 1 quart to 2 quarts 25W oil. The oil was dirty in 10 minutes of hot idle, so a changed it with cheapo oil twice on each time running through rpm ranges for awhile, then changed the oil to 10w 30 mobile. I did this awhile ago like in 99, when the car had 68k. Also I must say that you should not try this as nitro is very flammable, and results vary, even though the stuff cleaned any moving part, and the oil passages. I did not drive the car with nitro in the crank. I also look back and think what a risk I took doing that, with a possibility of engine detonation, and personal injury. I used to use 10% nitro mixed in thinner to clean diesel engine parts, the rags had to be put in a blast proof grounded container.

My original engine still runs strong at 160K miles.