Do short oil changes really clean better?

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I was thinking of the best way to clean a possible dirty engine.
1. Short oil changes
2. Run high detergent oil
3. Use a quick flush product
4. Use a slow cleaning/flush product

Does running an oil to a reasonable oci leave enough detergent/dispersant that short changes are just a waste?

Your thoughts?
 
I think it depends on the engine, the engine's history, and what your calling a short or long OCI.

All 3 of my vehicles I have owned since new, none are known problem children as far as sludge or oil dillution. Not overly concerned.

If I were to buy an engine of unknown history, I would likely run a short OCI ie 3000 mile for a few cycles, then back to a 5-6K OCI - which a lot of people would call a short OCI as well?
 
I think it matters as to what is getting cleaned. Varnish, I don't think comes off. Hard carbon neither. But sludge? maybe.

Probably makes more sense to cut open the filters and see what is coming out, and gauge by that.
 
I agree with what others have said - it depends on whether you're dealing with unknown history or neglect. I suspect the wisdom of running one or more short OCIs as a cleaning effort has more to do with loading up the oil and/or filter with dislodged contaminants, whereas exhausting detergents/dispersants in the short term is less of a concern.

Edit for typo - on/one
 
I think it depends on the engine, the engine's history, and what your calling a short or long OCI.

All 3 of my vehicles I have owned since new, none are known problem children as far as sludge or oil dillution. Not overly concerned.

If I were to buy an engine of unknown history, I would likely run a short OCI ie 3000 mile for a few cycles, then back to a 5-6K OCI - which a lot of people would call a short OCI as well?
I would consider short as 1,000-2,000 miles. To me any decent motor oil today should do 5,000 miles, especially Syn oil.
 
Verify engine for 'dirt' prior to anything.

1. And yes, a hated by the environmentalists 3000 mile interval can clean a dirty engine. No additives are needed. Clean rate might not be as fast as snake oils or hyped products.
2. That would be every current spec oil.
3. Optional and I recommend avoiding until you have a couple 3k intervals
4. Full interval snake oils have their pros/cons. Not needed until you determine dirtiness level.
 
I was thinking of the best way to clean a possible dirty engine.
1. Short oil changes
2. Run high detergent oil
3. Use a quick flush product
4. Use a slow cleaning/flush product

Does running an oil to a reasonable oci leave enough detergent/dispersant that short changes are just a waste?

Your thoughts?
At it pertains to your title the answer is no. All short OCI's do is force you to dump whatever garbage has dislodged and melted into the oil pan. Oils don't stop cleaning until you go way up in the OCI.
 
I was thinking of the best way to clean a possible dirty engine.
1. Short oil changes
2. Run high detergent oil
3. Use a quick flush product
4. Use a slow cleaning/flush product

Does running an oil to a reasonable oci leave enough detergent/dispersant that short changes are just a waste?

Your thoughts?
Other than the nominal cost and waste, I don't see how it could harm anything and if one is trying to save and clean and engine it makes sense to me to use a flush product and inexpensive quality oil and run 1 or more short OCIs. Some might say that things dislodged could clog small passageways but I think I'd rather take that risk in a controlled environment than a "wait and see" approach while on a road trip across Arizona for something important.

Engines are very expensive and important, so $50 to try to rehabilitate a dirty one with a couple of quick OCIs makes sense to me. And if you're changing at 1000 miles, rather than 5000 miles, you're still getting 20% of your use out of the oil while also dumping it early to try to remove contaminants.
 
Oil "Detergents" dont clean. You need the proper base oil/chemistry.
If you use the correct product and your engine is dirty
it will be cleaning you dont want all the gunk in suspension for a long drain.

I do think on most engines a 1000mi or 2000mi "clean up oci" is unnecessarily short with the exception of break-in wear on a rebuilt engine.

Most flush products are somewhere between "Does nothing" and damaging.
 
I would consider short as 1,000-2,000 miles. To me any decent motor oil today should do 5,000 miles, especially Syn oil.
Agree on 5k as a “minimum” unless you’ve got a known heavy fuel diluter like Honda’s Earth Dreams, or you’ve done UOAs before 5k and found you’re out of grade on viscosity. Then you either need to up the viscosity and/or shorten your OCIs…
 
Agree on 5k as a “minimum” unless you’ve got a known heavy fuel diluter like Honda’s Earth Dreams, or you’ve done UOAs before 5k and found you’re out of grade on viscosity. Then you either need to up the viscosity and/or shorten your OCIs…
I do 5000 mile intervals with Honda 1.5t but use ESP 0w30.
 
I was thinking of the best way to clean a possible dirty engine.
1. Short oil changes
2. Run high detergent oil
3. Use a quick flush product
4. Use a slow cleaning/flush product

Does running an oil to a reasonable oci leave enough detergent/dispersant that short changes are just a waste?

Your thoughts?
The best oil I have personally seen really clean a varnished, sludge, engine was when I was a Nissan tech. Titan came in with a low oil pressure problem. Pulled pan and screen was plugged. Pulled valve covers, looked terrible, varnished and like tar. He said he changed oil 10,000 miles. Mobil 1 0w40 was used bc it’s stocked for GTR. And bottle said helps clean engines. told him to change oil no more than 3,000 miles to see if the engine cleans up. 6 months later the engine was cleaned well.
 
API oils are not formulated to clean, that's not part of any standard. What they ARE formulated to do is keep things clean; not produce significant deposits during regular use, though that may not actually happen depending on the application and usage profile, as the additive package can get overwhelmed and once that happens, so do deposits.

Your typical API oil isn't formulated with anything polar enough to do cleaning. Group II/II+ and Group III/III+ base oils have poor solubility.

Oils contain:
- Dispersants: These prevent the agglomeration of particles that make their way into the oil so that they don't ball together and become heavy enough to fall out of suspension.
- Detergents: These attach to contaminants as they enter the oil, keeping them in suspension and preventing them from plating out on surfaces.

These products are not designed to liberate existing deposits from surfaces, drawing them into the lubricant.

If you have some soft deposits, it's possible that clean oil flowing over that surface could pick-up some of this, but anything that's really "there" like varnish/lacquer/sludge needs to be either dissolved by a solvent, which carries with it some inherent risk, or attacked by something polar, like an ester or AN, which will actively (but slowly) pick apart these deposits and draw them into suspension.
 
Not here to argue with anyone. Here to learn or provide my perspective.

I've read numerous articles on the roles of detergent additives. While, yes, one role is to suspend contaminants, acids, etc. to prevent deposits and sludge (prevention being very important), a primary role is to clean surfaces of sludge, varnish, etc. Here are just two quick cites to support my informed belief.


"their first job here is to clean the metal components of the engine in order to make them free of any kind of deposits."


"main function is to keep the inside of the engine clean, so that the insoluble matter generated is in a colloidal suspension state, and it will not further form carbon deposits, paint film or sludge. Specifically, its role can be divided into four aspects: acid neutralization, solubilization, dispersion and washing.... carbon deposits that have been adsorbed on the surface of the component, and disperse it in the oil to keep the engine and metal surfaces clean."
 
Clean the throttle body w/ CRC GDi cleaner, replace pcv valve, top quality oil filter, pea fuel additive in tank, Pennzoil synthetic oil and @High Performance Lubricants EC30. Change oil every 1500-2500 miles.

Might as well do a drain and fill on coolant and transmission fluid just for good measure too.
 
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