Marvel Mystery Oil??

[Bob S.]

Hello -

I'm considering doing something I NEVER thought I'd do; try an oil additive to cure internal engine problem(s)!

I bought my '67 L79 about a month ago and have only driven it short distances 4 or 5 times at 35-40 mph while keeping it to less than 2000 rpm. The car was kept by a widow for about 17 years after her husband passed away, and apparently received very little attention during that time. The car is very original, complete and unmolested.

The engine exhibits symptoms of valve sticking; an occasional, sporadic backfire thru either the exhaust or the carb. Though this hasn't recurred, in one instance a lifter ticked for a few seconds after startup before becoming quiet.

The engine has fresh oil, but I'm considering trying Marvel Mystery Oil after searching this site and finding a few positive comments on it. Should I add it to both the crankcase and the gas tank? ....and in what proportions? ....or just follow the instructions on the can?

About 10 years ago a coworker who had a C4, and was knowledgable about tribology, routinely put something instead of motor oil (I can't remember what) into his crankcase at every oil change and then drove it briefly (an hour maybe) to clean everything out, before installing fresh engine oil. Anyone have any 1st hand knowledge (ie successful experience) with such a 'home remedy' for removing varnish/carbon buildups???

I don't want to damage the valuable original engine in this car, but would also like to avoid a teardown if possible.....

Thanks.

Regards,
Bob S.

[Mike McKown]

Re: Marvel Mystery Oil??

By all means, try it. It's highly detergent and even makes a good penetrating oil. I've used the stuff mostly on small engines for the same problems you describe with good results. No negatives that I'm aware of.

After you add it, take the car on the road and drive if for several hours. I think you'll see a difference. Maybe a big one.

[Roy B.]

Re: Marvel Mystery Oil??

I talked about this many time running a spray of water down the Carb at a high RPM knocks out any carbon. But only friends trust my method or old farts that know and done this.

[Mike M.]

Re: Marvel Mystery Oil??

substitute Milwakee's Best in place of water. mike

[Roy B.]

Mike that works too *NM*

[Dennis B.]

Re: Mike that works too

You might try a similar product called Rislone. I run it in all my cars at every oil change. It's from Shaler Products.

Dennis #41966

[Ray G.]

Re: Marvel Mystery Oil??

Hello Bob S.

Experienced similar problems, as you describe, over the years. The problem seems to be the hydralic lifter plungers traveling into a varnished area inside of the lifter.
Mystery oil works, and there are similar products specifically labeled as "reducing engine varnish", that are added to the oil.
Carbon in the combustion chamber can be reduced, as previously described by Roy, with water. There were water injection systems sold in the '60s for that reason and also claiming to add horsepower by the steam and oxygen produced.
You can make a system by tapping into a constant vacuum source w/ a hose and a metered orifice (restrict the water inlet to a .030) Let the engine run at 1500 -2000 RPM for 15 minutes. Then disconnect your injector and allow the engine to run fast idle for another 10 minutes to clear itself. Pull the spark plugs and check them against each other looking for unusual deposits.
Hope this helps, Ray

[Jim K.]

Re: Marvel Mystery Oil??

I remember learning a similar trick in my Corvair days, a 2 liter bottle of water poured S L O W L Y down each carb to help clean out the carbon... ah, the memories!

[Terry F.]

Re: Marvel Mystery Oil??

People have blown head gaskets that way because the expansion of water to a gas is incredible. I would not recommend it on an engine I cared about. Terry

[Terry F.]

Re: Marvel Mystery Oil??

I recall a method of doing an oil change and substituting one quart of oil with one quart of automatic transmission fluid (it is extremely high in detergent). Run the engine until it stops making the lifter noise. DON'T drive the car, just let it idle fast in your drive way. Make sure you change the oil filter and drain the oil and refill. I believe I read something like this is a Chevrolet manual. I would be concerned about how much junk/sludge is on the inside of the engine. You can break all that stuff loose and send it to the filter. You might want to run it a while and then change the filter and then run it again. Hard to tell. A good detergent motor oil might fix it also. Just let it idle and get good and hot. It will probably loosen up.

Terry

[Mike McKown]

Re: Marvel Mystery Oil??

That procedure used to be done in Chevrolet garages. I think it was contained in a TSB for the '62 327 engines that developed a knock from carbon between the piston and head. I've done it myself on a number of occasions on older engines that had oil burning issues and built up carbon.

There was also a procedure released by Chevrolet in '55 that instructed the mechanic to put Bon-Ami glass cleaner down the carburetor throat on V-8 engines that had oil burning issues. The abrasive Bon-Ami would help the chrome rings of the day to seat in.

[Dick W.]

Re: Marvel Mystery Oil??

I have done the Bon Ami trick several times. In the early '60's it was almost impossible to get chrome rings to seat. On the large diesel we would ride down the road with a container of kerosene and Bon Ami mixed. We would slowly feed this into the air intake thru a tube attached to the intake with a small funnel on the other end.

[Mike McKown]

Re: Marvel Mystery Oil??

You didn't say if it worked or not.

[Tom B.]

Re: Marvel Mystery Oil??

Throughout the '70s Chevrolet had a problem with extensive carbon buildup on piston tops. I had a '72 Chevelle 350 that started knocking like it had a rod out. The water trick performed by the dealer fixed it. GM also sold a product called Top Engine Cleaner for the same use. The proceedure with Top or water was to run a warmed up engine at an elevated rpm while pouring a trickle of Top through the carb. When you poured it in it would slow the engine down and then you would stop pouring, holding the higher rpm until the engine recovered. Then pour again.

The difference in the 2 proceedures are that with water you would just keep repeating the pour and rev until the exhaust wasn't blowing out anything other than steam.

With the Top you would repeat the pour and rev for the 1st half of the can then, holding the rpm high, you would dump in the remainder of the product stalling out the engine.Now you would let it soak for 1/2 hour or so and then restart the engine, reving it until no more junk was blowing out of the pipes.

A word of caution; if you do this with a cat converter equiped car the converter must be disconnected before the proceedure or it will fill up with the junk that blows out of the engine.

As for blowing head gaskets, I have done and seen done this proceedure hundreds of times in dealerships that I worked in with never an engine problem afterward that didn't exist before. Sometimes it really was a rod bearing. I suppose that you may be able to damage an engine if that was your intent by litterly dumping a large amount of water in a fast running engine but the proceedure is a slow trickle.

As for additives. I believe in a product called Sea Foam. You can get it at many parts stores including NAPA. I use it every spring when the Corvette seems to want o run a little rough after sleeping all winter. In the gas it smoothes it out before the first tank is used. In the oil it desolves varnish and should stop your ticking, assuming that you don't have a damaged lifter.

Tom

[Lyndon S.]

Re: Marvel Mystery Oil??

I have real good luck with a product called CD2, you can find it at as Terry would say FALPS

Kelly