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Hot Rods Whats the pro and cons on flushing out old oil with engine flush

Discussion in 'The Hokey Ass Message Board' started by Bruce Fischer, Mar 9, 2017.

  1. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,490

    Rusty O'Toole
    Member

    A little off topic but if you really want a clean engine install a Frantz oil filter along with the stock full flow filter. The Frantz will catch fine particles of dirt and sludge the regular filter misses. Over time it will get your engine clean inside.
     
    Old wolf and Bruce Fischer like this.
  2. If the pan is wide open and has good access, just take your time. It becomes a matter of comfort more than anything. But you may be opening a bigger can of worms.
     
    Bruce Fischer likes this.
  3. wicarnut
    Joined: Oct 29, 2009
    Posts: 6,246

    wicarnut
    ALLIANCE MEMBER

    Bruce, thinking, " If it is not broke, don't fix it" applies for this situation, just change oil, filter, often at first, remember to add ZDP additive and run it. A little smoke from breather is no big deal and flushing/cleaning will not stop blow by anyway, you might open a huge can of worms. You should be able to pull rocker covers to see amount of sludge you are dealing with, but as always, there's many opinions here, hate to see you have to pull and rebuild engine if not necessary.
     
    Bruce Fischer likes this.
  4. borderboy1971
    Joined: Oct 20, 2008
    Posts: 743

    borderboy1971
    Member
    from Canada

    I believe your question was "pros and cons of engine flush" (the following has nothing to do with the zinc content of the oil)

    For your particular case, you have an old engine that has for most of its life used engine oil that didn't have good detergents in it. These types of oil (non detergent) contribute to the buildup of guck inside the engine. So the following applies to your situation.

    Pros....if you flush the engine and it does what is supposed to, you will have a very clean engine inside.

    Cons......you will very likely have a leaky engine that you find may make noises and in general be "worn out", more so than you may realize right now.

    On engines that have been running a good detergent oil (most engines since 90's....since good detergent oil has been common since then), should NOT benefit much from an engine flush if the engine has had regular oil changes. If it has not had regular changes, it will likely see the same results as an older engine like yours.

    With today's good detergent engine oils, when draining the used engine oil on a regular basis, the oil should come out black.....this is the detergent cleaning out carbon etc. If it comes out clean, it's not doing its job.

    In my experience the best detergent for the money, is to simply substitute a quart of transmission fluid at an oil change every once in awhile....(4 quarts oil and 1quart trans) for example, and then change the oil earlier than normal. ....but don't be scared to drive it for a few weeks.

    IMO I wouldn't do any type of flush, or the Trans fluid thing to any old engine that I'm not planning to take apart. If I wanted to try to clean up the inside a few weeks prior to a rebuild, I'd consider flushing the hell out of.....it might help the clean up process for rebuilding easier.
     
    Last edited: Mar 10, 2017
    indyjps and Bruce Fischer like this.
  5. Gene, that make me feel a little better. I don't see any smoke coming from the draft tube. When I had the 56 Buick station wagon at a red light the smoke coming from the draft tube was so bad people though I had a fire under the hood.LOL.So I feel better about this motor in this Chrysler. Thanks Bruce.
     
    Last edited: Mar 11, 2017
  6. Thanks Wicarnut.I feel better after reading all the replys to this thread.ThanksBruce.
     
  7. Borderboy , after reading all the replys to this thread, there is no way I am going to flush this motor out. Thanks to you all. Bruce.
     
  8. crossthread
    Joined: Mar 9, 2006
    Posts: 103

    crossthread
    Member

    Hi Bruce I am not on here every day so I didn't know about all the threads ,but then my wife says I don't know much about anything but" Damn old cars " I believe you have to raise the engine as high as
    4 inches to get the pan to clear the front .Its been 40 years or more since I had to work on one. the diesel
    oil is in a lot of store ,just make sure it's not for tier 4 engines .Like you I am not all that happy about crawling under a couple of tons old steel .I'm getting a few years older myself , and the getting down on the ground is pretty damn quick, If I don't knock myself out the getting up takes a bit
     
    Bruce Fischer likes this.
  9. YEA Bob, we don't want to do that here.LOL.Bruce.
     
  10. Crossthread, aint the truth.I don't know if you read my thread way back when I was putting the new exhaust on the 56 buick wagon .The exhaust was new but laid around for a while. I didn't know some mice had made a nest in the exhaust pipe.When I was under the wagon I grabbed the pipe and mouse shot out of it and right up my shorts{it was during the summer} scared the crap out of me and I conked my head right on the frame. I think I knocked my self out for a few seconds but then laughed to my self. Bruce.
     
    Last edited: Mar 11, 2017
    arkiehotrods, Spoggie and 45_70Sharps like this.
  11. 283john
    Joined: Nov 17, 2008
    Posts: 814

    283john
    Member

    I know, right? Every time I get on this site there's somebody asking some question about stupid antique cars. Shit gets old after a while.
     
    pat59 likes this.
  12. The engine flush crap works quite well at busting everything loose. The problem is the engine can't deal with it, PEOPLE need to clean the loose junk out of it. Running engine flush right before you pull the engine is a great idea.
     
    Bruce Fischer likes this.
  13. 45_70Sharps
    Joined: May 19, 2010
    Posts: 331

    45_70Sharps
    Member

    Now that's funny shit right there!
    I could just imagine my reaction, and yes..... I've smacked my head good when startled under there

    Sent from my SM-G920V using The H.A.M.B. mobile app
     
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  14. southcross2631
    Joined: Jan 20, 2013
    Posts: 4,381

    southcross2631
    Member

    Back in the days of non detergent oil, Glass bottles in a rack at the pumps . Flushing was common. I worked at a full service gas station, remember those ? With a mechanic and a wash bay and someone that pumped your gas and
    washed your windshield and checked your tires. Oh yeah, they spoke English too.
    we used 2 quarts of diesel fuel and 3 quarts of oil , idled the car for about 15 minutes drained and changed the oil and filter if it had a filter. Never had one start smoking or knocking or blow up.
    Don't know that I would do that today, but when your a teenager and making 80 bucks a week and your boss tells you to do it ,you do it and do it as best you can.
     
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  15. Bruce....after graduating high school I bought a 56 Bel Air to get back and forth to work and play with on the weekends.
    The Chevy was clean but probably had been around the clock once and maybe twice in its 8 years of road use.
    Didn't appear to smoke (much) and had a very slight gurgle to it when pushed a bit hard.
    On the advice of some old timer service station owner I drained the oil and filled half with Mystery Oil and half with regular engine oil.
    20 minutes down the road on the down side of a long hill I couldn't see out the rear window from the tremendous amount of smoke pouring from the back.
    A week passed and a lot of smoke before I dumped the stuff and returned to normal 40 W oil plus a can of STP.
    Car got me through that summer until the growl became a rap.
    Never did flush in a bottle after that.


    Sent from my iPad using The H.A.M.B. mobile app
     
    Bruce Fischer likes this.
  16. 45 70Sharps I got even with the mice they had another nest in the tail pipe and stayed in it while I installed it. My stepson said when I fired up the motor on the old buick 3 or 4 of them along with the nest came flying out the tail pipe. Getting even is a bitch . LOL. Bruce.
     
    2many projects likes this.
  17. 2many projects after reading all the replys .There is no way I am going to flush this motor. I am going to try some M.M.O. before I change the oil and filter and do what Crossthread said to do and try diesel oil .Bruce.
     
    2many projects likes this.
  18. indyjps
    Joined: Feb 21, 2007
    Posts: 4,122

    indyjps
    Member

    I use trans fluid in the oil to clean them out. Even do it on my high mileage daily driver, 1/2 quart every few changes.

    Clean under the valve covers best you can, shop vac it, new oil and filter, quart of trans fluid and put some miles on it. I feel this dissolves the gunk slowly instead of breaking it loose in big chunks that will clog up the pump.

    I have used the flush, half oil half naphtha, ran it til it was hot. Drained out big chunks, I feel I got lucky that I didn't blow it up, never again.
     
    Bruce Fischer likes this.
  19. borderboy1971
    Joined: Oct 20, 2008
    Posts: 743

    borderboy1971
    Member
    from Canada

    My how things have changed. In today's time....."when your a teenager and have the strange desire to work (if your mother and father don't just give you money) and your making more than 80 bucks a day, and your boss tells you to do it, you don't do it because you don't want to, and you let the person that actually WANTS and NEEDS to keep their job to do the best they can".
     
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  20. 73RR
    Joined: Jan 29, 2007
    Posts: 6,551

    73RR
    Member

    I'll add to this.
    Back in the old-days, just after fire was 'invented', we didn't have a lot of options for the cars we were actually able to buy and 'well used' was just a starting point. It was not uncommon to run a Diesel oil and 30w mix to clean up/out a tired engine. My running buddies and I never 'lost' an engine doing this but there is no way to know if the results were any better than what we had before. The logic was that Diesel, while it is a light-weight oil, it is also a fair solvent that, hopefully, would dissolve the sludge slowly and not cause great hunks to fall into the pan.
    The process was simple: warm up the engine, drain the oil and replace the filter. The first round consisted of 5 qts of Diesel. Let it idle for 20 minutes and then drain the mess and put in a new filter. Round 2, and sometimes round 3, consisted of 2qt Diesel and 3qts of detergent 20w or 30w. With this we actually drove it around for 20-30 minutes then back to draining the oil and installing a new filter. I had a couple of heaps that I continued to use 1qt of Diesel for several oil changes.
    With all that said, would I do it today? Maybe; if the engine is in that sad-of-condition then what's the worst that can happen? It is probably scheduled for a rebuild anyway and getting some of the crap out before disassembly is a good thing.
    YRMV.

    .
     
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  21. sunbeam
    Joined: Oct 22, 2010
    Posts: 5,185

    sunbeam
    Member

    Bruce to drop the pan you have to remove the exhaust if it's stock. Old exhaust never comes off easy and usally not in good shape. Running old engines that may have had low or non-detergent and replacing it with high detergent oil can remove carbon behind the rings and increase oil use. I do use a zink additive in all my engines with flat tappets.
     
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  22. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,490

    Rusty O'Toole
    Member

    If the engine is caked with sludge on the inside I would rather that junk stayed harmlessly glued to the sides of the engine than flushed loose and circulating in the oil, chewing hell out of your oil pump and bearings, or plugging up the oil system.
     
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  23. gene-koning
    Joined: Oct 28, 2016
    Posts: 2,328

    gene-koning
    Member

    Years ago, I bought a 66 Dodge wagon with a poly 318. Though I bought it for parts, one day I needed transportation, so I got the old poly running. I changed the oil, and drove the car for a few months before the valve cover gaskets started leaking. When I pulled the covers, the top of the motor was so loaded with gunk, you could see the imprint of the rockers in the build up inside the covers! I scrapped and dug out as much as I could, and discovered the reason for the oil leak was because the oil return passages in the back bottom corners of the heads were both plugged up. I hooked up an old speedometer cable to a drill motor and wallowed the gunk out the holes. I changed the oil and filter again, and watched to be sure the oil I was adding was returning to the pan before I installed new gaskets and continued driving the car. Because I needed the car for transportation, I never tried any kind of a flush, on the advice of my boss at the full service station I worked at at the time.
    About 3 months later, I had valve cover gaskets leaking again. The motor had the same issue, the 2nd time, plugged return ports in the heads, and covers covered with gunk. Another cleaning, reaming of the oil return passages, oil and filter change, and reassembly. About every 3 months I got to repeat the process again, and each time it was a little cleaner then the time before. Off and on over the following 3-4 years, I drove that car over 25,000 miles. When I finally parted the car out, the 318 still purred like a kitten, with all its original parts (other then valve cover gaskets) still intact and just over 150K miles. Some guy bought the motor to rebuild it, I have no idea how that came out, but he knew the oil issue when he bought it.

    What I'm saying here is change the oil & filter and drive the car. Don't try to do any extra cleanup it doesn't need unless your prepared to pull the motor and overhaul it. Gene
     
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  24. Will do Gene. Bruce.
     
  25. patterg2003
    Joined: Sep 21, 2014
    Posts: 682

    patterg2003

    My uncle Elmer put on 90 miles a day in the 60's & 70's commuting to work. I rode with him to college for a year. He changed the oil regularly and used diesel grade Shell oil that was bought by the case. He said he used the oil as it was doing its job as the oil always came out black. He said it kept the engine clean and happy. My uncle's cars ran on the prairies where they did not use salt so the body was good when he traded the cars in with about 160,000 miles. He always got good money for the cars when he was getting ready for a new car. I remember him telling me that he had a couple guys chasing him to buy his 66 Dodge and got decent money for the car.
    It may be wise to do any change in increments so that there is not a total and instant release of the sludge. Consider a mild approach to eventually get the engine in a better state.
     
    Bruce Fischer likes this.
  26. I just this Saturday bought a setting and rotting M Farmall Tractor. I have every intention of getting the engine unstuck and using the tractor. yesterday I removed the spark plugs and filled the cyls with a mix of diesel and auto trans fluid. I didn't see any evidence of water being present in the clys. I think it will free up without much work. I also pulled the drain plug out of the oil pan. A bit of water and some not too bad looking oil came out. And When I get it home the very first things I intend to do is pull that oil pan and clean it and the intake screen. And the valve cover is coming off and the rockers and pushrods removed and cleaned. The valves will all be checked to be certain that they all move up and down.
     
  27. I agree with your assessment.
     
  28. 73RR
    Joined: Jan 29, 2007
    Posts: 6,551

    73RR
    Member

    Bruce, aren't you glad you asked....?:p
     
    Bruce Fischer likes this.
  29. Years ago I made a real rookie mistake. Doing a valve cover gasket on a customer's slant-6, I decided to scrape a bunch of crud out of the oil run-down passages to eliminate the oil from pooling up top. Well... got it back together and the oil light was on quickly. Down comes the oil pan, the screen was blocked with the crud I sent down to the pan. I should have dropped the oil first. Now, let sleeping dogs lie is my motto with old clunkers.
     
    Bruce Fischer likes this.
  30. Patter, I am going to start using the diesel oil once I find a carb kit to get the old girl back on the road. Thanks Bruce.
     

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