Adding Diesel Before Oil Change

Messages
223
Location
Massachusetts
Someone on another forum posted that he does this. He warms up the motor then drains a quart of oil, then adds a quart of diesel. Then he runs it a few minutes and drains. Claims the new oil stays cleaner longer. He has been doing this for years and hasn`t had a problem. Is this a bad practice even though he does well with it?
 
Messages
47,771
Location
Everson WA - Pacific NW USA
Probably not hurting much....but some of that diesel stays around. Just use a good oil...or if you inherit a dirty beast, use AutoRx for a safer true cleaning. Visual appearance of oil can be misleading.
 

tpi

Messages
200
Location
So. CA
quote:
Originally posted by jeremiah2360: Is this a bad practice even though he does well with it?
Yes if for no other reason a waste of time. It is unlikely to have a benefit and will leave a little diesel behind for the new oil. If the engine needs to be flushed at every oil change, the interval needs to be revised.
 
Messages
90
Location
Coos Bay, Oregon
I just dump in a quart of something like Rislone and drive it the 10 miles to the oil change place. I don't think a quart overfilled hurts anything and all three of my cars are clean as a whistle. One is an '88 Camry with 410,000 on it, uses no oil, and passed smog...
 

driven2services

Administrator
Messages
0
quote:
Originally posted by CoosBayDave: I just dump in a quart of something like Rislone and drive it the 10 miles to the oil change place. I don't think a quart overfilled hurts anything and all three of my cars are clean as a whistle. One is an '88 Camry with 410,000 on it, uses no oil, and passed smog...
That's not doing you anything either, Rislone is just a 20 weight oil withouit any detergent. Thers a VOA on it somewhere...
 

TC

Messages
1,644
Location
California
Gunk/Solder Seal "5 Minute Engine Flush" is an exotic, complex, highly formulated mix of...(drum roll, please...snicker, snicker)...90% diesel fuel. If you use straight diesel and simply mimic the instructions on the Gunk product, you should do just fine. Per the link below, they add a quart bottle (15 oz bottle for smaller crankcases, I believe) without first draining oil to a cold engine, then run it stationary (without driving the vehicle) for 5 minutes. Then replace both oil and filter. I'm no chemist, but I suspect that the diesel will have some amount of solvent effect on any sludge in the engine. (In other words, it works, at least modestly. Crude, but effective -- an old school remedy which still has merit.) If you have heavy deposits of any type in your engine, a "go slow" approach may be better so you don't possibly clog oil channels. Maybe Auto RX or a high-detergent diesel motor oil for a couple oil changes. http://www.gunk.com/prodinfo/MF3.PDF http://www.gunk.com/msds/MF3.PDF ("CAS 68476346" = diesel) [ February 07, 2004, 09:32 PM: Message edited by: TC ]
 

jeremiah2360

Thread starter
Messages
223
Location
Massachusetts
Just to clarify. He does this to thin the oil for a better drain. He is not doing extended drains. Someone on the other forum(not an oil forum)said it was unwise. He said he has never had a problem doing it. I am just curious to know what you guys think. Thanks!
 
Messages
4,478
Location
Southern California
Diesel fuel is very close to kerosene. As such it does have solvent properties, yet its viscosity also endows it with a degree of lubricity. As long as the engine is idled unloaded, it's unlikely any mechanical damage is ocurring since there's still the remaining fill of motor oil mixed with it. The amount of remaining diesel fuel in solution with the new oil fill is trivial and will evaporate off with use. Is the practice actually worthwhile? Probably not. Neither is ordering a $2,000.00 serving of puffer fish*, but, people do it anyway. *a lethal last meal if prepared incorrectly
 
Messages
3,329
Location
Bolivia
I don't see the point in it. There are people here who drain all the oil, fill with diesel, gasoline, or a mixture and run it a few minutes. There are others who fill it with laundry detergent and water and run it a few minutes, then rinse with diesel. All say they have never had problems and that it helps extend the life of the engine to 100,000 km. They refuse to believe that an engine should last longer. Just use a good oil in the first place. If you want it cleaner, change sooner. I took the valve covers off my gasoline 1988 BMW 325ic(200,000 km) and 1995 Diesel 4Runner a few weeks ago just to look. Both have been on a regular diet of Group I 20W-50 Diesel/Gasoline formula oils (books for both say 20W-50). The BMW gets changed twice a year, the 4Runner 6,000 km. Neither had sludge. BMW had a little carbon, probably because my wife drove home without water in it one day and cooked it. 4 days with a product like Auto Rx and the BMW lost all the noises that had become "normal", so I know there was varnish in the lifters that is no more. I'd rather use a product designed for getting the varnish out than a fuel.
 
Messages
39,805
Location
Pottstown, PA
quote:
Gunk/Solder Seal "5 Minute Engine Flush" is an exotic, complex, highly formulated mix of...(drum roll, please...snicker, snicker)...90% diesel fuel.
I always thought that the stuff was just a repackaged quart of kero. That is, I agree.
quote:
I'd rather use a product designed for getting the varnish out than a fuel.
So would others ..but these techniques (diesel, kero, tide [Big Grin] , whatnot) have been in use for decades before AutoRx (I never EVER heard of the stuff before this forum) and other products "designed" for this very purpose ever existed. Those techniques had merit for decades and probably have some merit now.
 
Messages
6,388
Location
Washington St.
Diesel fuel is a poor solvent...kerosene is a much better solvent--I've used both to clean parts, heavy fuel oil strainers, etc. People do all kinds of goofy things and say, "I've never had a problem." OK, and 1) they can't prove that it did any good, and 2) if they did cause themselves a problem they'd clam up anyway. Don't pour diesel fuel, kerosene, ATF, or anything else through an engine. If you really feel the need, pour a 89¢ quart of the correct engine oil through while the drain plug is out to wash out the oil pan better. I'm not saying that it does any real good, just that it may make some folks feel more useful. Ken
 

driven2services

Administrator
Messages
0
quote:
Originally posted by widman: There are others who fill it with laundry detergent and water and run it a few minutes
Oh god...do people actually do that?! [Eek!]
 

TC

Messages
1,644
Location
California
There are certainly times when an engine "cleaner" can be helpful, and the old-school products and solvents most definitely still have merit. My mom's old '69 Mercury wagon comes to mind. Back around 1980, when we gave up on a persistent engine tick as a permanently defective lifter, a mechanic suggested we try Marvel Mystery Oil. The tick was gone within a week, having removed whatever carbon/sludge/varnish that had called the lifter home. Yes, better to avoid most of these lube problems through regular oil changes, but such issues can still arise, especially when acquiring a used vehicle. [ February 08, 2004, 10:56 PM: Message edited by: TC ]
 

driven2services

Administrator
Messages
0
So what would happen if someone completely filled a block with naptha and let it soak for a while? I guess that would probably clog things up... [Smile]
 

TC

Messages
1,644
Location
California
A naptha soak could be a problem, but Auto RX would not, if only for the fact that the cool, en-vogue thing to do on this site is talk-up products like Auto RX, and trash-talk anything old, proven, and low-tech because they're not...well, they're just not cool. And nobody likes an oil nerd!
 
Messages
5,112
Location
Airlie Beach Australia
Hi, as somebody else suggested earlier - we should not forget successful past practices I would never use diesel for the purpose you indicated - use kerosene instead A note from the past; a 1961 Mercedes Benz OM326 ( 190hp diesel engine ) Workshop Manual suggests the following 1 - To test Oil pump flow, use a mixture of 50% engine oil and 50% kerosene 2 - A mixture of 50% engine oil and 50% kerosene can be used to flush the lubrication system But why not simply add a litre of cheap oil once the drain plug has been removed? Regards
 
Messages
526
Location
Manitoba Canada
Although I have heard of folks using diesel fuel in the crankcase as a laxative to flush things out, more often the "old school" method was to add kerosene to the motor oil. Matter of fact, for cold winter temps -10 F or worse, older shop manuals and operator manuals for HD diesel motors recommended running SAE 10W with up to 10% kerosene to thin it out. One effect was that the oil filters plugged more often. Another effect was the motor was spotless by next spring. Since I was around heavy machinery as a child, and can remember that far back, the kerosene trick appears to have worked with little if any damage. A word of warning: kerosene and diesel fuel are far more volitile than motor oil. If you put this mixture into a newer car with PCV, EGR, oxygen sensors, and God Help You catalytic converters, you could experience an ugly situation: the O2 sensors could fail and the cat could melt down. Jerry
 

TC

Messages
1,644
Location
California
Valvoline/Pyroil "5 Minute Engine Flush" is 90% kerosene (MSDS below), and as mentioned earlier, Gunk/Solder Seal's similar product is 90% diesel fuel. (Kerosene, #1 diesel, and JP4 jet fuel are all similar products, but not the same.) Seems reasonable to suspect that these products aren't ruining engines left-and-right when used as directed, so it's fair to say that a quart of straight kero or diesel won't likely harm an engine either. (Sludge or varnish monsters just waiting for somebody to break those deposits loose into the oil channels might be an exception.) Heyjay's interesting comments about compatibility with newer emissions controls might help explain why these are limited to "5 minute" flushes..? http://msds.ashland.com/ShowMSDS.asp?M=0214576&C=005&D=503&L=EN&F=ANSI&N=PYROIL+ENGINE+FLUSH+12%2F30+OZ [ February 09, 2004, 02:14 AM: Message edited by: TC ]
 
Messages
809
Location
Granville, Ohio
Twenty years ago I had an old '76 MustangII that had some type of sludge problem. I remember hearing a screeching noise one day at starup, pulled the head cover and found the galleys to the camshaft lobes completely plugged with gunk. I used a wire to open them up, then upon the recommendation of a mechanic friend, I pooured a quart of ATF in the crankcase and changed the oil 100 miles later. I didn't have any problems after that. I sold the engine on that car a few months later. The guy who bought it took the oilpan off to inspect it, and told me that it looked like a new engine inside - no deposits. I realize that doesn't mean that the ATF didn't do any damage or that it would be safe in modern cars. But it apparently does a good job of cleaning things up.
 
Messages
897
Location
owatonna, mn
I've got a few friends that do the ATF trick everytime before an oil change. I've heard ATF doesn't have many detergents in it, but it's decently safe since it's a 10w oil. I'm sure someone will chime in.
 
Top