Marvel Mystery Oil???

[Bingster]

I'm about to start the engine after a few years of sitting.  Don't know if it means anything but the fan turns easily.  Anyway, I raed on the Matvel Mystery Oil bottle that adding a quart to an oil change loosens sludge and deposits. Is that something that I want to do?

[3046moparcoupe]

Hello Bingster:

 

Almost 2 yrs ago I purchased a stock 46 Plymouth Coupe with the oem 218 flat six in it...it ran quietly and didn't smoke but appeared to be super neglected just like the rest of the car. Before I started taking the car apart, I spent about 2 weeks messing with the motor (new plugs, changed the oil, kitted the carb, etc.).

 

I really wanted to go with modern detergent type oil, but before doing so - I asked much the same question you are asking here....I also spoke with some folks from the historic vehicle society here in the DFW Tx's area about it...and here's what I learned.

 

The old non detergent oil would allow Carbon to settle in the bottom of the oil pan and also to form /collect on other areas of the engine internal surfaces....not knowing about the history of my motor I was advised to pull the oil pan and look before putting any detergent oil or additives in. When I pulled the oil pan, the crud was solid across the bottom about a 1/8 - 1/4" deep....took me hrs with scotch pads and acetone to get the stuff off and cleaned up...I also could see some of the buildup attached to the lobes of the crank, etc...

 

The folks I spoke with told me to clean the inside of the oil pan and also to do the area where the valves are located, then once clean - you should be OK to go ahead with detergent type oils......

 

I don't know about the history of your motor, or if it's still the stock flat six,...but if you suspect sludge buildup in your motor, you don't want to disturb the stuff with detergents that might break it free, as then it will circulate through your entire engine...

 

My understanding also is that the oil filters on the old flat six motors don't work the same way as a modern engine oil filter does,....the modern filters are more like an in-line filter, filter 100% of the oil when the motors runs,..the old filters were like a bypass filter and they filter only a portion of the oil flow while the engine is running...another reason why the crud you might break free could run around inside the engine longer than you'd like, with the potential to do damage, clog things up, etc..

 

When you turn your fan blades, all you are turning is the bearing in the water pump, so I wouldn't use that as an indication for thinking the motor is free, although if your car has been sitting inside a garage the past few years, that should not be concern for it trying to freeze up on you...my suggestion to you would be that if you want to turn the engine by hand before cranking it, move down below the fan to the crank shaft pulley to actually turn the motor over, (you could remove the spark plugs prior to doing this and maybe just a small squirt of oil into each piston before hand turning),...

 

Then before starting, unplug your coil wire and crank the engine over a bit with your starter to get oil up and circulated a bit through the engine before firing it up.

 

regards

 

Steve

[Bingster]

Thanks! I do have the flat head six and I have no idea what condition it is on the inside.  I'm firing it up to see how it runs.  By the way, if you have any tips on flushing the cooling system I'd like to hear them.  I have the repair manual and see how they connected their special tool, but a flush set I bought seems not to fit the hoses.

[greg g]

Marvel Mystery Oil is a blend of Stoddard solvent, light petroleum oil as a carrier, and some sort of red coloring.  Stoddard solvent is mineral spirits. 

MIneral spirits are recognized for their ability to break down chemical bonds, allowing thining, blending and clean up. 

[mrwrstory]

After about 7000 miles my rebuilt Dodge Hemi developed an intermittent lifter tick.  Intermittent, like weeks apart.  Sometimes it was after the car sat unused for a week or when only having been idle for an hour.  I initially used Rotella, a diesel engine oil, for brake in of about 2000 miles because of the extra zinc.  Than I switched to standard 10w30.  Sometime time after a second 10w30 oil change the lifter tick started.  I dreaded the thought of tearing down the engine to replace a single lifter.  It's a big job.  On the advise of several experienced professionals I tried Marvel Mistery oil figuring, it couldn't heart.  After adding a quart, and the car idling about 2 min., the tick disappeared.  I now have about 300-400 miles with an oil change back to the Rotella, there has been no re-occurance.  I'm keeping my fingers crossed!

[Sharps40]

If you are starting and old and likely dirty motor after a long sit, plan on regasketing it anyway.  Especially the front and rear main seals.  They will most likely leak anyway.  After the restart, when you regasket, a minimal job is to clean out the gunk you can reach from the motor. 

 

Its not the detergent oil that ruins the old seals, they are dried out, tired and worn already.....in any event, you won't get all the gunk out unless you do a full teardown like for a rebuild.  So, I'd not run a detergent oil either for start up or after a regasket.  The stuff you can't clean out by hand will break loose and potentially cause issues.  So, short of an overhaul that cleans all the parts and chasing out the oil gallies, etc, run non detergent oils and hands off the internal cleaners.

 

If you decide to give it a proper overhaul/hot tank, etc...have at it and run whatever good oil you like. 

Edited May 18, 2016 by Sharps40

[casper50]

A week before I tried to start my engine for the first time I put a squirt of MMO and ATF, 1/2 and 1/2 mix, in each cylinder and let it set.  Smoked on start up for a bit but ran fine and the rings weren't stuck.  They might not have been in the first place.  Don't know.  Didn't hurt anything that I know of.

[austinsailor]

A couple comments.

1. My experience on several motors that sat for 40 years or so turned out fine. As mentioned above, I pulled the pan and valve covers and cleaned what I could. Refilled with rotella, and after an hour or two smoke quit and they've done fine. I attribute it to the high detergent loosening up crud on the rings and letting them seat.

2. Your standard rotella no longer has much zinc. They are at version J, most zinc was removed for emissions reasons. Standard rotella is still fine oil, but if you're buying it for the zinc, read on.

They still make version H for the Detroit diesels. Old formula, lots of zinc. I've only found it by the drum (I have 1 and 1/2 drums left. If you don't want to buy it by the drum, read on.

They are now selling it in gallons in an even older version - F, I think it is, and call it "for older cars" or something to that effect. I've seen it in Walmart.

Not telling anyone they need zinc, but if you care, you have options.

[3046moparcoupe]

Your dead on about the zinc being removed from our automotive oils,...the removed it because zinc getting past piston rings causes catalytic converters to fail....for what it's worth, you can buy a zinc additive at Autozone...

[3046moparcoupe]

Bingster, when I attempted flushing mine the 1st time, I purchased a bottle of Prestone Radiator System Flush at Oreilley's, which you just pour in and run/idle the engine for a period of time as directed on the bottle, then drain, and refill the system with your distilled/antifreeze mix.

 

In your case - if your wanting to flush it out before starting it up,...I would remove the upper radiator hose and look inside the thermostat housing to see if their is a thermostat in place,...if so - remove the housing (it's easy enough to make a new gasket if you don't have one, however I think you can get that gasket at either Napa or Oreilley's), and remove the thermostat,...then remove your lower hose to the radiator and point it downward as much as possible,...now you can back flush straight through the block by flushing into the thermostat housing and having it exit out the lower radiator hose coming off the side of your water pump.

 

Radiator same way, with the hoses off you can flush water straight through it - however my experience's would dictate that it's pretty hard to help a radiator much by just running the hose through it...if it's got problems/blockages...

 

Steve

[Bingster]

Thanks guys. Appreciate it.  My knowledge on engine interiors is nill.  How difficult is it to replace the gaskets you mention?

[_shel_ny]

A good flush needs all 5 welch plugs on the driver's side of the engine removed to get all the crud out.

[Bingster]

Will they come out easily?  What I mean is, will they come out without a fight?

[austinsailor]

Getting them out is easy. Just drive a punch or similar through them and pry. Putting new ones in without leaks is the trick.

[Bingster]

I knew there must be a catch.

[Don Coatney]

Use a self tapping sheet metal screw and a pry bar to remove them.

 

[Bingster]

Thanks.  Where do I buy new ones? Roberts? Rock Auto?

[ptwothree]

Bought all of mine at the local NAPA store.  Get the brass ones if you can...steel plugs rot out and then leak.

[Jeff Balazs]

Replacing the welch plugs isn't that big of a deal generally. You do need the correct domed shaped brass ones though and you need to clean up the sealing surface at each opening. There is a product which really helps prevent any leaks. I can't remember the name of the stuff ......I want to call it Indian shellac?  Napa carries it and it comes in a small bottle with an applicator brush. If you paint the sealing surfaces with this and then knock the welch plugs in properly you should not have any issues with leaks.

Hth.

Jeff

[Young Ed]

Brass ones are better but don't be afraid to use the steel ones if that's all you can find. I'm pretty sure I've got steel ones in my truck and car and they've been in there over a decade each. I use permatex #2 non hardening sealant.

[Reg Evans]

You're probably gong to find some engine block chili behind those freeze plugs.

 

[Bingster]

Gee, is there any engine left inside?

[Jeff Balazs]

Brass ones are better but don't be afraid to use the steel ones if that's all you can find. I'm pretty sure I've got steel ones in my truck and car and they've been in there over a decade each. I use permatex #2 non hardening sealant.

Ed;

I was suggesting the brass ones as they are a little bit easier to work with and will not rust out over time. .

Jeff

[Reg Evans]

Coat hanger wire works well to get around corners and scratch as much crud loose as possible while running water down the thermostat housing after removing the thermostat. 

You'll still have an engine block left and the engine will run cooler.

The last car I resurrected was a '33 Plymouth.  It would overheat after only a few minutes of driving.  I discovered this crap in the radiator. I only caught part of what came out.

The previous owner had left the radiator cap off and the rodents moved in.  I back flushed the radiator in place by duct taping a garden hose in the lower radiator hose and turning on the hose full blast.  She runs cool now.

 

 

 

[Bingster]

This is good info.  I'm wondering if before I do the full nine yards, if I should start the engine and see how it runs. Change the oil, oil filter, etc.