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"Motor Flush" at oil changes?

Discussion in 'The Hokey Ass Message Board' started by 63Biscuit, Jun 4, 2008.

  1. Seems I've got a few oil changes to do in the near future...curious what experiences/recommendation folks have using a "motor flush" as part of an oil change. I seem to remember an old timer deal of dumping a pint of kerosene in the crankcase, and idling the (warm) motor for 10 minutes or so to dissolve crud. Probably a hald dozen products on the shelf of the local parts place now. So...whatcha got?
  2. JohnEvans
    Joined: Apr 13, 2008
    Posts: 4,883

    from Phoenix AZ

    Don't do it!! any engine made since the mid 50s you won't be doing it any favors. That stuff is a hold over from the poor quality oils of the 20-30s and engines with no oil filters.If you really feel the need to flush do a couple of 200 mile oil/filter changes.
  3. roddinron
    Joined: May 24, 2006
    Posts: 2,677


    This is a practice that got started way back when oil and engines weren't very refined (pun intended). I think if you change your oil on schedule and use a good quality oil, it's not necessary. It's always bothered me to put something in to clean an engine. I'm so concerned about good lubrication the rest of the time, then why would I put a solvent in there and let it run not really knowing what it's doing to the parts. Seems like it could do more harm than good to me.
  4. Retro Jim
    Joined: May 27, 2007
    Posts: 3,859

    Retro Jim

    I have done that before but I used a quart of kero and let it run for a few minutes . In the 60's I also heard of that done many time to get the slug out of the engine. I also use to dump trans fluid down the carb to help cleans the valves with carbon build up . Worked pretty good ! Well good luck !

  5. upzndownz
    Joined: May 26, 2006
    Posts: 297


    you shouldn't have an excessive amy of sludge if you've been using quality oil and you have a properly operating PCV system on your engines
  6. Retro Jim
    Joined: May 27, 2007
    Posts: 3,859

    Retro Jim

    Maybe I should of ask what engine and year are you have too ? The other posts are right , if you change your oil often you should be OK . The kero trick is for the older engines due to the crap they used to add to the oil ! Like I stated I have done that before BUT on older engines as last resort . USE good oil and good filter and when you change your oil make sure the engine is warmed up too. Do it allot for a few times and see how it looks , But do use GOOD oil !!!
  7. Twisted6
    Joined: May 27, 2007
    Posts: 514


    The Biggest Draw back of useing any engine Flush espcaily on a OLD motor and has any kinda crappy build up is it will end up in the Pickup screen,And That will be Plugged and then hummmmmmm No oil pressure. So if your doing that because of Old oils build-up Then spend the money to take off the Intake and valve covers and clean the motor out that way.Then you won't be driving down the road woundering why you no lonnger have any oil pressure.Because
    The pick-up screen is pluged due to flush & sluge brake-up.
  8. Willy301
    Joined: Nov 16, 2007
    Posts: 1,426


    I agree with most that has been said, but when I have an engine that is starting to leave the oil black soon after it is changed, I add a quart of Trans fluid about 100 miles before the oild change. If the motor has been neglected and is very dirty, disassembly is your best bet for a clean well lubricated engine. I run Fords and we all know they have small drainback holes is why I started doing it.
  9. Motor is a 71 Chevy 292 inline 6 out of a C30 with 55K on it; pulled in running condition. In its former life, it worked on a farm, and was coated in about 1/2" of grime given that pretty much every gasket on it had cracked and not been replaced. I suspect it may have seen it's share of "tractor oil" over its life, and it did OK with a compression test. At the minimum since getting it, I've used conventional Valvoline oil in it. Have always been of the school that expensive oil and filter are cheaper than a budget rebuild!
  10. Bob Dobolina
    Joined: Jul 27, 2006
    Posts: 332

    Bob Dobolina

    you want to stay away from anything that says "Motor Flush" on it. Most of those products are extremely caustic, and provide no lubrication. Stick with the trans fluid, as stated above, or possibly some Rislone, before each oil change.

    just my .02
  11. Mopar Mama
    Joined: Nov 19, 2007
    Posts: 234

    Mopar Mama
    from Boise, ID

    Any goo you have might be helping your compression...If you are reasonably sure your rings are good, a product called Seafoam is awesome. Add it to your oil, idle as directed and change. I've only used it in my fuel, but am debating doing this in my Plymouth. Also use a NAPA Gold filter. I won't run anything else. Excellent filter, and I'm not just saying that because I work there. ;)
  12. Iceberg460
    Joined: Jun 6, 2007
    Posts: 880


    On an older motor with a lot of sludge its a VERY bad idea. Have seen several motors at the shop i work get trashed after oil flushes cause the sludge gets broken up, ends up in the oil pan and clogs the pickup and u have no oil pressure like said above. That said, we use a product called BG 109 and it seems to work pretty well on newer low milage cars. U put it in just before u do the oil change, and let it idle for 20min. Then change the oil, start it, let it run for another 20, and do another oil change to make sure u get all that crap out of there.
  13. G V Gordon
    Joined: Oct 29, 2002
    Posts: 5,698

    G V Gordon
    from Enid OK

    I had an old '55 F100 years ago I used as a daily driver, parts chaser, and tow car for my old stock car. Ran fine, 6cyl, 4spd. Decided to do the old girl a favor one day, plugs wires points, oil change and ran a quart of Rislone through it just to "clean it out". Found out I had a cracked head! Cleaned all the crud out of the crack and it started leaking compresion into the water jacket, and oil from between the head and block.

    If its an old High milage engine I wouldn't do it.
  14. If you got too much crud in the engine the only proper fix is to tear down,clean,and replace gaskets and parts as ness. I do have a story on this so here goes. This cat brings his car to the shop for a oil change. Tells me he hears that Rislone is good for cleaning up the insides of the engine. Well he was right. It cleaned all the shit from the top side and dissolved it into a gunk of shit that clogged the oil pump screen.That 24.95$$$ oil change ended up costing him about $2995.00 by the time we installed a new long block. I have no problem with Rislone but it has it's place.>>>>.
  15. anyone who take proper care of their car doesn't need a motor flush. i thinks it a scam by these quick change businesses as an add on to sell to mrs. car owner.
  16. 73RR
    Joined: Jan 29, 2007
    Posts: 6,516


    Alot of good advice above. That being said, in the 'old' days, on 50's engines that were full of sludge, we would get the engine to operating temp then drain the pan, leaving the filter intact, and put in 4-5 qts of diesel oil. We would then run the engine at idle for 5-10 minutes then drain and refill with oil. Diesel, or #2 fuel oil, is oil, approximate 5w. As bad as the ULS fuel is, it still lubricates things like injector pumps which are pretty sensitive. If there is evidence of big chunks in the oil I would probably leave well enough alone.:cool:
  17. PetChemBill
    Joined: Jun 1, 2008
    Posts: 15

    from Delaware

    I agree that trying to flush heavy sludge deposits out of an engine is asking for trouble. I have, however, used Rislone successfully three or four times to free up a clacking hydraulic valve lifter. This was done on engines that did not have unusual sludge deposits. Incidently, a good gasoline additive to remove deposits from valve tulips is Marvel Mystery Oil. Marvel is a "top cylinder oil", and the same top cylinder oils are added to some brands of gasoline at the refinery to remove valve deposits and certain other intake system deposits. One reason Chevron "F310" additive was so effective was it's high concentration of top cylinder oil.
  18. David Chandler
    Joined: Jan 27, 2007
    Posts: 1,101

    David Chandler

    I went down the kerosene road once. Like they said it clogged up the oil pump screen. And pulling the intake later on, I found there was still a ton of sludge in the valley area.
    If it truly has 55K on it, then hopefully it won't be that bad. I'd just change the oil and filter at short intervals and see how quickly it gets dirty. If you are running this thing "as is", don't go looking for trouble, unless you want to rebuild it. You could and probably should pop the valve cover and the side covers, and see what lurks under them, sence you noted that it was leaking, and should have it's gaskets replaced anyways.
  19. in2hotrods
    Joined: Aug 24, 2005
    Posts: 26


    I've used trans fluid before, heck I've used brake fluid before. Both are cheaper than motor flush which has no lubricating qualities about it. I'm sure you want the gunk out but as stated above...where will the gunk end up?
  20. gonmad
    Joined: May 17, 2007
    Posts: 1,753


    I used kerosene once. But ONLY because I mashed out every pushrod end and still had to drive it about 300 miles to get it home with the same oil. The only reason I did it when I got home was in an attempt to get more of the loose metal out of the engine. I only ran it about a minute. If I recall correctly, that engine still has the same bearings in it with another 10,000 miles on it!
  21. draggin'GTO
    Joined: Jul 7, 2003
    Posts: 1,753


    Not a flush, an engine cleaner.

    Cleans slowly so it doesn't break off the crud in big chunks.

    Pretty interesting stuff, its main purpose is to clean up the piston ring pack so the engine regains compression and better oil control due to the freed-up rings and cleaned-up ring lands.

    I've used it on a couple of my fairly low-mile late-model dailys to keep the crud from building up. I'm currently running a bottle of the stuff in my 455 Pontiac (good-running 1974 original short block).

    I don't sell this stuff, thought it might be a good thing so I tried it. A lot of the guys on the forum say good things about it.
  22. toddc
    Joined: Nov 25, 2007
    Posts: 981


    If it ain't broke, don't fix it.
  23. cruiserbuddy
    Joined: Oct 21, 2005
    Posts: 397

    from Germany

    When I know, I have to disassemble an engine and the engine is stuffed with mud everywhere inside, then I put half a litre of brake fluid in and let it run for a few 15 minutes. But only if I know, I have to disassemble it afterwards for some reason......
    Not during a normal oil change...
  24. El_Gato_Scott
    Joined: Aug 29, 2004
    Posts: 282

    from So. Tex.

    What about Seafoam? Seems like it might be more like Marvel Mystery Oil. I've run it through a tank of gas before to remove moisture, but it does say it can be run through the crankcase and is an "upper cylinder lube". Seems like it was maybe intended primarily for marine use, outboard motors, etc., so it should be an oil/petroleum base rather than a solvent.

    Here's a link

    Anybody have much experience with it?
  25. gallagher
    Joined: Jun 25, 2006
    Posts: 180

    from califorina

    i do a few 1500 mile oil changes and add a can of bg s moa oil additive i dont like the idea of running a flush i refuse to sell them at work cause all the negitives problems it can cause
  26. HotrodBoy
    Joined: Oct 15, 2005
    Posts: 235


    I have used Wynns engine flush for many years, there is 2 grades, the one we in the trade buy and the one sold in the retail stores, the trade one is stronger. It works well in keeping internals clean in most engines, and yes it does cause problems with engines that are choked up with deposits but hey these are engines that should be stripped and rebuilt or dumped. I have seen some of my customers engines still very clean internally after 50000miles with regular 3000mile servicing. It is good for diesel engines too because it gets rid of the sulphur deposits.
  27. Judd
    Joined: Feb 26, 2003
    Posts: 1,894


    I change my oil every 3,000 miles and have never had one that didn't look like new inside. I've cleaned the crud from the valve covers and top of the heads on old motors I've bought, ran high detergent oil on 3,000 mile change and had the botom of the motor look like new when I disassembled it later. I make shure the motor is hot when I change the oil also.
  28. zman
    Joined: Apr 2, 2001
    Posts: 16,553

    from Garner, NC

    wives tail... it's about the worst thing you can do. You're basically running the engine with no real lubrication, then you're not gonna get it all out either. Chunks of shit floating around. Clean and rebuild the motor or just use a quality oil and change it fairly often. There is no substitute or quick fix for doing it correctly.
  29. 1931S/X
    Joined: Apr 5, 2007
    Posts: 667

    from nj

    i once bought a cheap 85 diplomat daily driver, a 100,000+ mile car for 100 bucks, it was a former detective car. it sat for a long time before i bought it, i started checking it out real good before putting it on the road, it had a dealer installed oil presure guage as part of the police package, i noticed after idling for about 3-5 min, the oil presure would start to drop, it made me believe there was a ton of sludge in the pan. for the 100 bucks i spent on the car i figured what the hell, ill try the engine flush in the metal can. didnt have much to lose. it worked wonders. after 2 oil changes the problem went away and i put 40,000 miles on it with 0 problems till the head gasket started to leak coolant. oh yeah ive been told many times not to use detergent oil in an old angine and what not... i took a chance and it worked.
  30. I'll vote with the ones who are worried about the bad lubrication and the sudden rush of junk circulating through the delicate bearings, and the loosened up grit being ground into the machined surfaces.

    I would strongly recommend several oil changes in a row, at very frequent intervals. That will serve to clean the engine and remove the junk in a controlled manner. Most oils can keep a certain amount of small particles in suspension, to be drained out at oil change time.
    I believe that overwhelming the engine with a rush of flushed out junk would be like sending grinding compound through the engine.
    I am in favor of using many, and frequent, oil changes to remove the gunk in a safe manner.

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