Won't hurt nuttin' much... as long as you don't make a habit of it...
I've used Marvel's for the same thing, and it worked on my old truck... (un-stuck a sticky lifter)...

There's basically two kinds of additive... thinners and thickeners...  Thinners have things like iso-alcohol, kerosine, naphtha,mineral oil to penetrate sticky lifters and gunk... thickeners are motor honey, and make oil too heavy to pass leaky seals and rings (crooks use motor honey to sell dying cars to suckers)...
Don't use them more than once every year or two, and no harm...
Rislone never worked for me,... try Marvels Mystery Oil for sticky lifters... (but only once, and don't try to go 10,000 miles on that oil change... 2 or 3k max)...
JMHO...

Thanks guys!

I had a bad experience with marvel mystery oil. I put it in my old bronco and it broke loose some old burnt oil in the pan and it clogged up some oil passages and made the oil pressure funky for about a year, until I sold it off, told the new owner who promised to tear it down and fix it, but got rear ended and ended the bronco's career.

When I was in high school I worked at a garage and Rislone was one of the products used regularly when someone had a noisey lifter.  It was a rural area and most arterial roads where 45mph, the back roads were all 35mph.  For months you might drive 5 miles to work and back and never go over 45mph.....and your car ran 15 minutes going to work and then 15 minutes going home.  And for most people the oil changes were infrequent.....the 3,000 mile club was not yet invented then.

It was not uncommon for engines to get sludged up and an oil change that included a bottle of Rislone often calmed the noisey lifters down.  Marvel Mystery Oil and Kano Kroil as similar solvents, and help with engines that are gummed up.  Problems might occur if the engine is really sludged up.....and the solvents loosen up too much stuff all at once.


 

Every 3 or 4 oil changes, my dad used to put in about a gallon of kerosene and let the engine run for a minute then drain the oil with kerosene out.  It was amazing how much thick black sludge would drop out of the pan as the oil was draining.

He never had an engine let go on him.  No seal leaks. Only 1 valve cover gasket leak I can remember.

justin_o_guy2 wrote on 03/05/14 at 10:38:32:



Kinda what I have been told. Nice PM, but wont fix whats already bad.

I doubt Ive had the valves covers off of more than 10 engines, one of them was loaded with gunk. I asked what oil theyd used, it was Pennzoil, Ive never used that stuff since,, I know, thats not fair, I have no idea IF they changed the oil or how often, I dont remember why we pulled the cover, or if I even continued with the project.. I have been known to walk away from things that look like a waste of time..

You guys remember those old Matadors?( 72/73) A guy in the AF had one, absolutely gutless piece of crap, decided he wanted to rebuild it.,.mite have been 5 or 6 of us in that,, My big part of the project was keeping parts organized so it would go back together. Sadly, NO ONes job seemed to be knowing enough to solve the problem while it was apart..
Did anyone know we needed to hone the cylinders? Noooo,, so, we slapped rings in, never touched the valves & called it a "Rebuild",, HA!! BUncha 18 y/o kids with no experience at all. Amazing we even got it back to gether..