HELP!

[jbxx]

OK guys ( n' gals)
I have a problem ( well maybe more than one).
First let me fill in the people that may not have read my previous posts.
Sorry to repeat! I bought a 53 M-37 and decided to have its engine "professionally" gone through and rebuilt.
That way I figured I could work from a solid base as I have limited mechanical experience.
I don't want to put how much I put into it, but the oldsters can atest it was beucoup .
From the begining I had rough starts after leaving it for three weeks to a month between starts.
It would start up fine after the initial start, so I can't really fault the builder for not catching this.
There was some atomized particles at startup (looked like large vapor water).
The gas is not the problem as I would run her dry and use new gas with a marine tank.
I have about 150 miles on the rebuild ( 4 yrs ago).
I change the oil every year even though there was not much milage.
Nothing was obvious in previous oil changes. I would decant the oil into a jar to observe any anomilies.
This time the oil came out like drilling mud.
I'm assuming water (coolant) contamination.
From my limited mechanical knowledge I have either a cracked block, which I don't deem very likely as the block was magnafluxed at the rebuild and I have never had the block hot.
Or, I have a leaking head gasket, which is what I am hoping for.
I'm keeping my fingers crossed that I haven't toasted the engine.
So my next steps will be first, a compression test, then a leakdown test, then probably change the head gasket
and check the head for true.
Any ideas or opinions are really appreciated.
Thanks J.B.
P.S. with the valve inspection covers removed I'm seeing the large vapor stuff coming from the bottom of the engine
mostly beteen 1 & 2 cyls. Pics upon request.

[Lifer]

It certainly sounds like water contamination to me. You're on the right track on how to isolate it, too. I'm hoping it's simple and "cheap"...like a bad head gasket.

[Joe]

Running the M37 dry and then letting it sit for several weeks to a month is probably not be a good idea. The gaskets in the carburator will probably dry out and start to shrink and cause various air and fuel leaks and that can cause all sort of rough running and idling. If it were me I'm try to find some non-ethanol gas and when I was ready to store it, drain the ethanol gas and refill with straight gas with some stabilizer in and run that long enough that the ethanol stuff is completely flushed out of the fuel lines and carburator. A full tank also keeps better than an empty or near empty one because the less the air volume in the tank the less air will be pumped in and out as the temperature changes and the fewer air changes will also mean less condensation. if you can't find ethanol free gas then store it with the regular gas left in it and try adding a gas drier for the water that always seems to be in ethanol gas. Also try it with and without a combination of gas stabilizer.

[MSeriesRebuild]

Do you see multi-colored swirls on top of the coolant when you remove the radiator cap? Looks like a rainbow. Typically when you find what you describe, a cracked block is the issue, most often it will be around the valve spring area where the top of the spring seats against the block casting. Have seen lots of folks replace head gaskets with high hopes, never have seen it work though. If it was the gasket, it would have to be leaking from a water port letting coolant into the combustion chamber, generally if that is the case, you will be getting excessive flow out the radiator overflow tube as compression pressure would be leaking into the cooling system as it is much greater than cooling system pressure.

You are doing the right thing by draining that fuel system, today's gas left sitting will cause you far greater problems than the carb sitting dry will ever cause.

[jbxx]

I didn't see any evidence of oil in the coolant.
Do I remember something about one or more of the head bolts that need to be coated with something.
Because they penetrate through a coolant cell?
J.B.

[hbb]

J.B.
You might check the cooling system with a pressure tester and pump up the cooling system and remove the spark plugs and see if you get coolant in any of the cylinders and check the plugs for signs of burnt coolant. Or you can go the other route of adding compressed air to each cylinder like you are performing a leak down test or simply perform a leak down test making sure the pistons are at TDC of the compression stroke, and watch for bubbles in coolant if you do not have a leak down test gauge set. This will isolate which cylinder you need to concentrate on!

hb

[8543bob]

GOOD MORNING,
IF YOU GOT A CRACKED BLOCK OR FAILED HEAD GASKET; THE FIRST PLACE TO LOOK FOR SIGNS OF WATER CONTAMINATION IS INSIDE THE OIL FILL CAP, OR DIP STCK CAP. WATER VAPOR WILL RISE AND FORM DROPLETTS ON THE INSIDE OF THESE CAPS. RUN THE ENGINE TILL NORMAL TEMP AND THEN CK THE INSIDE OF THE CAPS.
GOOD LUCK, BOB

[MSeriesRebuild]

I didn't see any evidence of oil in the coolant.
Do I remember something about one or more of the head bolts that need to be coated with something.
Because they penetrate through a coolant cell?
J.B.

All head bolt threads need to be sealed with high temp thread sealant. If coolant is coming past threads, it should show up outside if the gasket was sealed correctly at installation. Did you have someone else assemble the engine? Hopefully your service would be better than what we can get from outsourcing, we absolutely do all our own assembly in house. Seems it's virtually impossible to get anyone else to do it right so such incidents do not occur.

[jbxx]

It will be a couple of weeks till I get back to the trucks' location so info will be slow.
I did not do the engine myself. Supposed "professional" rebuild/ reinstall.
Are we talking a Locktite type product, or something different for head bolt sealing?
Tnx.
J.B.

[cuz]

Many companies make thread sealers. I prefer Permatex. For the last 45 years I have used Permatex #1
http://www.permatex.com/products/Automo ... ealant.htm

but Permatex also makes the fancy sealers as well for those tough applications.

http://www.permatex.com/products/Automo ... ealant.htm

[MSeriesRebuild]

It will be a couple of weeks till I get back to the trucks' location so info will be slow.
I did not do the engine myself. Supposed "professional" rebuild/ reinstall.
Are we talking a Locktite type product, or something different for head bolt sealing?
Tnx.
J.B.

What we use is a product specifically for sealing threads, Permatex high temp thread sealer, white tube with red lettering. Do not mistake this for Permatex #1 or #2, they are totally different products made by the same Co, but with a different purpose in mind. Lock-Tite also offers an equivilent product for thread sealing.

[cuz]

Permatex #1 was around years before the Super Trick thread sealer specific fancy tubes. #1 is more than adequate for head bolts and studs. I've never had any leak in my 45 years of bending wrenches.

Permatex® Form-A-Gasket® No. 1 Sealant
Fast-drying, hard-setting sealant designed for sealing rigid materials and flanges, or patching holes and joints where permanent assembly is desired. Temperature range -65°F to 400°F (-54°C to 204°C); resists common shop fluids and fuels.

Suggested Applications: Freeze plugs, threaded connections, manifold gaskets

[jbxx]

More info:
I got the head off this weekend, but neglected to drain the block so I botched one critical
t- shooting clue as I dropped coolant into the cylinders.
I have three questions.

1.) The TM manual says to coat the gasket with a high temp grease or sealant. I remember in the old days we used to use something called copper coat or copper seal. Is this still SOP?

2.) There were "O" rings above the head gasket and below the head on each stud ( see picture ). I see no mention of this.
Is this a good idea?

3.) There is no oil in the coolant. If there was a leak between oil and water it would seem to me that you would go from a higher pressure system to a lower pressure system. e.g. from oil to coolant not vice versa. Can anybody think of a mechanism that would get coolant in the oil? And not the other way around?

Thanks for all ideas and help
J.B.

[jbxx]

My boss had an interesting suggestion.
Could it be a perforation in the fuel pump?
What does the oil look like when it's contaminated by gas?
J.B.

[Lifer]

I don't remember what the stuff was called that we used to seal gaskets back when I was just a kid, but it was a brush-on product in a can with a red label and the words "gasket shellac" underneath a a black Indian head logo. It was pretty tacky stuff. My dad actually used some of it on a piece of a catalog page to make himself some fly paper one time.