Diesel flush engine oil

[MBLittle]

Heard a couple old timers claim that using diesel to clean out the oil works perfectly.

The claim is that you drain the oil, add new filter, half fill with cheap oil and regular diesel. Then run at idle for 15 minutes. Drain and change filter adding more cheap oil. Let idle for 15 minutes and change again with your regular filter and oil.

Looking for anyone that has actually tried this and care to share results.

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[model 10]

With a slight variation, I ruined an aircraft engine doing that. Rather than using diesel I used Stoddard solvent. The cylinder walls were scored.

[stevec195]

Please no! Don't do it. There is no miracle cure for an old cruddy engine.

[ontherocks83]

Negative! Oil is a lubricant hence why you need it. Diesel may have "some" lubricating qualities but those are designed for injectors not engine internals. The only way to clean oil sludge out of an engine from lack of maintenance is to re-build that engine. Like Stevec195 said there are no miracle cures for oil sludge build up.

[Sailmonkey]

Why bother? Changed on a regular schedule the oil will remain clean enough anyway.

[ontherocks83]

Originally Posted by Sailmonkey

Why bother? Changed on a regular schedule the oil will remain clean enough anyway.

+1

People give me crap about changing my oil too often but I can promise you that oil sludge will never be an issue with an engine if you change the oil at or before its recommended interval. I know it is a "waste" of money to change your oil more then it is needed, but I am of the mindset that

1) I would rather change out a still good slightly used oil with new oil rather then change out bad oil with new oil. If it never gets "bad" it can never cause issues.

2) I would much rather spend too much money on oil changes then ever have to spend money for an engine repair that was caused from an oil failure.

[sabray]

Just to drive the head of the nail home. No way am I doing that.


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[MBLittle]

But no one has tried it?

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[model 10]

Originally Posted by MBLittle

But no one has tried it?

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I did. It cost me an ovhl.

[Capt Phil]

If you want to avoid the sludge buildup and add years to your engine as well as months between oil changes, add a set of luberfiner filters to your engine. I had a couple of 25 year old CAT D330's in my trawler that came with a couple of luberfiners and when I checked the oil regularly, I had a difficult time seeing it on the dipstick it was so clean! Scared the hell out of me the first time because I thought I'd run them dry! I literally had to change the oil based on engine hours alone because it was as clean as when I did the last oil change! Filters are just a paper towel roll non-imprinted. Don't ask me what the cost but whatever it is, it's worth it... I wouldn't own a diesel without a set aboard... In answer to your original question, don't do it... the fuel will remove any residual lubricants and you will end up with scored walls or worse. Phil

[MBLittle]

Thanks everyone. Looks like something I'm not willing to try.

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[heron237]

RE: ONTHEROCKS,

Here we go with the oil change interval, why waste oil on too frequent oil changes and what do you get except "peace of mind".

Change the oil based on oil manufacturers/engine maker's recommendations, there is absolutely no reason to do it more often, it is wasteful on so many levels, modern mainstream lubricants never fail like your grand pappy's......

[model 10]

Originally Posted by heron237

RE: ONTHEROCKS,

Change the oil based on oil manufacturers/engine maker's recommendations, there is absolutely no reason to do it more often, it is wasteful on so many levels, modern mainstream lubricants never fail like your grand pappy's......

Yeah but these older engines are your "Grand Pappy's engines. The rate at which they muck up the oil is terrible.

[mermaidmom]

1. You never gave a reason for why you want to do this. I doubt very seriously you need to "clean out" the engine internals. As folks have said, most engine oils have sufficient detergent to keep the engine sludge free.

2. With that being said...I've used Seafoam in the crankcase of a Jeep to free a sticking lifter. Added the Seafoam to the crankcase oil, ran for a bit, changed the oil...voila. You can use Seafoam to do what your are talking about doing, but I don't think I would do it unless I felt I had a reason to suspect I needed to do it. Folk may claim it is just a snake oil, but it worked for me. Here's what their website has to say: Use Sea Foam Motor Treatment with crankcase oil in diesel engines - Sea Foam Sales Company

3. I've used kerosene in the crankcase of a neglected Ford as your old-timers described. But like Guy states, you really run the risk of causing more damage than solving anything. Engine was clean as a whistle afterwards...but I was tearing it down for valve/head work anyways. Not recommended without specific, well-founded reasoning.

[a64pilot]

Originally Posted by MBLittle

But no one has tried it?

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Yes, but don't use a flammable liquid as a run away in a Diesel is possible. Sea Foam works well, an old tried and true method is to replace on quart of oil with a quart of transmission fluid and leave it in for the oil change interval. It's essentially a high detergent 20W oil.
There are specific products made for this, called motor flush or similar, I suspicion they are mostly Stoddard solvent, which is mineral spirits, but you only do like a 20% mix, not 50%.