Add Diesel to the Engine Crankcase? Let's see what happens!

  • Published on: 07 May 2018
  • I've had a lot of requests to test diesel in the crankcase of an engine. Will it cause damage? Is it an effective crankcase cleaner? Can it be used in an emergency oil substitute? Let's find out! Thanks for supporting the channel!
  • Runtime : 11:
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  • Richard Booysen
    Richard Booysen   9 hours ago

    My experience with diesel as a flush, drain the oil, re fill complete with diesel, remove spark plugs then using the starter motor only, spin the engine let it spin for quite a while, Ps the diesel even provides enough pressure to switch off the oil light, Drain dirty diesel, refill with new oil, my experience, new oil stays cleaner longer because most of the sludge is cleaned out, My thoughts was that diesel on its own would not provide enough lubrication to protect a powered engine

  • Robert Jackson
    Robert Jackson   15 hours ago

    2008 thru 2010 f250 6.4 had this issue with diesel in the crankcase due to regen process. Normal 15 quarts of oil some folks reporting 20 quarts on 5k oil change. F250 owners were doing this test in real time with a 50k truck. Search internet 6.4 growing oil

  • Gary Cunningham
    Gary Cunningham   19 hours ago

    Just stop it. Stop it now. You are the Freddy Krueger of every small engine out there.

  • Dalton Michaels
    Dalton Michaels   1 days ago

    this may sound a bit crazy , but im fairly certain how well a fluid works as an oil (assuming were talking about fluids not meant to be used as oil) has less to do with the fluid you are using and more to do with the specific pump design in a specific engine. an older engine with a pump designed to pump viscous thick oils will develop less pressure as you use thinner and thinner fluids. But a oil pump out of some modern engine designed to pump zero weight oil will have no problem developing the same pressures with other thin fluids , i mean diesel probably isnt much thinner than zero weight oil heated to operating temps , what you will probably run into however is vaporization and foaming of the diesel in the crank case , you will loose diesel faster to the PCV than oil , and you will loose liquid fluid volume to foaming and aeration. i have talked to old school engine builders and alot of them used to pump diesel and or kerosene through engines to clean them out without having to hot tank them but only before taring them down for rebuilds, then flush them out with oil before first start up. so its defiantly a well known cleaning agent. and even decades ago they werent crazy enough to use it as an oil. I bet whoever has been using this idea to clean engines before oil changes created the idea themselves after miss interpreting what someone else told them, or were simply told wrong by someone else who miss construed the idea.

    STRUTZKOFF   1 days ago

    I mix half diesel and oil and over fill to clean inside the engine. Works amazing

  • GuretoSefirosu
    GuretoSefirosu   1 days ago

    I have not done this with diesel. I HAVE done this on many engines using 20%-25% kerosene. I even did this on a 318 Magnum V8 in my 1995 Dakota years ago. Never damaged anything and I only ran it for five minutes this way. It got goops of crap out the first time I did it. I bought it used. I was told that others use diesel but that diesel could soak into seals and things and it was bad.

    BULLET   2 days ago

    Stop wasting my time hit not interested....

  • Victor Vigil
    Victor Vigil   3 days ago

    I've done it in an engine on my vehicle and because I had just done an oil change and a moth later it was just as dark as when I changed it so I add some deisel and it cleaned it out and don't have that issue anymore

  • Milken
    Milken   6 days ago

    Too scared to put diesel in the crankcase. I simply don’t think it’s worth the risk.. as well, diesel will swell & destroy all rubber seals...

  • Mark L
    Mark L   6 days ago

    Test Coke or Pepsi mixed with oil as an engine flush.

  • whitebird77
    whitebird77   6 days ago

    will running 99% engine oil and 1% diesel keeps the engine running good and clean?

  • Lewis Hayes
    Lewis Hayes   1 weeks ago

    I bought a new 1994 Explorer and started using a can of motor flush every 4th oil change. From the first time I added it to the oil I noticed that the motor flush which was about 4.50 a quart at that time smelled exactly like diesel oil and had the same feel as JP5 jet engine fuel which is a type of kerosene. I started buying diesel by the gallon after that and used a quart every 4th oil change. I would drain the old oil and change the filter with the cheapest brand and refill the engine with the proper amount of the cheapest 30 wt oil I could find and 1 qt of diesel. I would run the car for about an hour or take a casual ride around and then again change the oil and filter again with manufacturer recommend oil and filter. I did this for the whole time I owned the car and finally sold it in 2005 with 242,000 miles on the engine less idle time. I never had a engine problem. The oil and diesel mix that came out after about an hour of operation was always black and looked like unchanged old oil.

  • SkyMax ABC
    SkyMax ABC   1 weeks ago

    Doesn't it cause the oil pick up strainer to carbonise?

  • mountainman1961
    mountainman1961   1 weeks ago

    I use diesel fuel just before changing the oil. Years ago my father was a big fan of Quaker state oil. I put deisel fuel in it and ran it for. 1/2 hour and it thru a rod. We took the motor apart and the Quaker state was so bad it slugged up the engine and when we put the deisel fuel in it loosen up the crap and caused the engine to blow.

  • Brian Andrews
    Brian Andrews   1 weeks ago

    I used approximately 3/4 qt of green diesel into the crankcase of a BMW m50 engine to flush it about 1 1/2 years ago. The engine had not been given regular oil chances by the previous owners and, when I removed the valve cover to replace a leaking gasket, I found what looked very much like potting soil on the head. After cleaning out as much “potting soil” as I could (even vacuuming out the head with a shop vac) and reinstalling the cover, the engine developed an occasional valve lifter chatter due to remaining dirty blocking the oil into the hydraulic lifters. I added the diesel (without removing any of the recently change oil) and ran the engine at, or slightly above, idle speeds until the engine was completely up to normal operating temperature. Afterward, I drained the conventional oil/diesel from the crankcase, changed the filter, and refilled with the proper amount of synthetic blend oil. I only have had one occasion of lifter collapse (at idle and within one month of doing the flush). The car isn’t driven often so it is almost time to change oil again (I change my oil every 3,000 miles). I think I will continue to use the synthetic blend oil but I will not flush the engine again. The engine has been running and sounds completely normal. At this point, I would call the flush a success. That being said, I don’t think I would attempt to run an engine (even at idle speeds) using only diesel for lubrication unless It was a “last ditch effort” for a dying engine before I gave up on it.I have also heard of draining the crankcase and filling it with household degreaser like Formula 409, etc., (at idle speeds) to degunk an engine. That might make an interesting video as well.

  • NakedBikeLife
    NakedBikeLife   1 weeks ago

    Little dangerous, but what about two stroke gas like 32:1 ratio. It protects the top end but could it protect the bottom end of a 4 stroke

  • MrFuncat
    MrFuncat   1 weeks ago

    I've used a diesel/gasoline mix in an engine that had been sitting for 30+ years to remove the sludge in the crankcase. Drained out what I could of the old oil and then added the mix, let it sit for about a week and the sludge was then able to be drained out after being dissolved by the mix. My dad had an old diesel tractor that had a fuel leak in the injector pump and caused the oil to be diluted by the diesel. In the end the engine had severe bearing noise.

  • Davis Phillips
    Davis Phillips   1 weeks ago

    I had an old 225 slant 6 looked like bearing grease on the valve train. Manually cleaned most and added a quart of diesel ran it an hour. I drained a lot of nasty out. Motor ran great afterwards. Love your videos. Thanks for all your hard work.

  • 777 Smitty
    777 Smitty   1 weeks ago

    we only used it on really nasty engines! just filled the engine completely full let it sit a few days then completely drain it out. the flush was next with cheep oil and a few oil changes

  • Andrew Williams
    Andrew Williams   1 weeks ago

    Try Kerosene next. Someone else on Youtube said to use it to clean your engine

  • The Watch Show
    The Watch Show   1 weeks ago

    Diesel 1to4 for a few minutes before oil change. Not a problem. But new modern oil will clean just as well.

  • Steve Robinson
    Steve Robinson   1 weeks ago

    What happens when you replace the oil with Astroglide?

  • James Nettleton
    James Nettleton   2 weeks ago

    One could add just half a quart of diesel to the crankcase. This would cut out most of the lubricity worries. Leave in there a little longer, still be a lot less sludge and less wear. Adding it to the petrol regularly at a quarter of quart of diesel to 20 gallons. Clean the upper cylinders and valves up gradually.

  • Jason Chicoine
    Jason Chicoine   2 weeks ago

    I had a 98 civic and every time it was due for oil change 60 miles before changing oil id add 1 quart of diesel , then regular oil and filter change i did that for over 100000 miles, when i sold it it had 320000miles and no burning oil ran like new however the engine leaked oil a bit but nothing excessive

  • col stace
    col stace   2 weeks ago

    If you do this to an auto engine, will it make the crankcase seals leak? What is seal leakstop additive that they sell?

  • sam grabel
    sam grabel   2 weeks ago

    Iv used two stroke in diesel fuel 🤔

  • Wilfred Signo Jr.
    Wilfred Signo Jr.   2 weeks ago

    Its okay kerosene flusing my engine suzuki swift 1/2 oil 1/2 kerosene?

  • Grant W. Whitwam
    Grant W. Whitwam   2 weeks ago

    It did prove that in a worst case event, using diesel is way better than using no oil at all, especially if it was run at a reduced RPM and load.

  • Caleb Baynton
    Caleb Baynton   2 weeks ago

    It will survive and it will be cleaned, one of our outboards fell of a boat, when we got it out of the lake part of the cleaning process was putting diesel in the crank to clean it this was for a 2 stroke

  • trevor peck
    trevor peck   3 weeks ago

    i thought the lubricity tests were 10 minutes!

  • John Lieske
    John Lieske   3 weeks ago

    Is still flush engines with diesel but always add around 2 quarts of oil .

  • John Lieske
    John Lieske   3 weeks ago

    The diesel from years ago was a better lubricant than the diesel of today is .

  • John Lieske
    John Lieske   3 weeks ago

    These engines are nothing like automobile engines .They are splash lubed compared to pressure lubed . And some of these engines did not have steel liners for the Pistons to run on .

  • John Lieske
    John Lieske   3 weeks ago

    Years ago use to run diesel / kerosene to clean out the engine and it works .

  • Jordan Chamberlain
    Jordan Chamberlain   3 weeks ago

    I really like how you showed the lubricity of the oil and diesel mixture for cleaning an engine. I’ve thought about doing it before, but I don’t like going out of manufacturer’s recommendations.

  • russgoyer
    russgoyer   3 weeks ago

    I acquired a GM vehicle with a 400 small block. The previous owners had never change the oil in 75,000 miles. They just kept adding to it. The amount of sludge was indescribable. I manually removed as much sludge as I could before flushing with diesel. Fully draining the crankcase and reapplying straight diesel, I ran the engine for 15 minutes. There was no visible evidence of destruction. But the Removal of sludge and deposits was extremely evident. This was an older engine, not subject to any warrantee so risk is minimal. The engine and vehicle lived to travel the roads another 20 years to my knowledge.

  • mike cochrane
    mike cochrane   3 weeks ago

    i would like to try this with the hopes of freeing up a possible stuck valve. i am posting here hoping that someone could help me identify this noise in my engine, and also wondering if your engine flush process may help extinguish my problem. anyones help out there would be greatly appreciated.