Engine: Would synthetic blend oil do this?

[StudeNewby]

On a previous thread, I had posed the question about vapor lock in my 64 Champ 259. The problem appears to have been solved when I removed the thermostat. It did not appear to be stuck as I could open it with some force with my fingers, but nevertheless it is now running cool as a cucumber. I'll take it.
Now onto the next crisis. While under the hood with the cooling system, I decided to change the oil for the first time since I bought the truck in April. I then drove it Saturday night and Sunday for a total of about a hundred miles, and it ran fine. Then Sunday evening when I started it up, it was misfiring badly and puffing blue smoke, and I could not keep it running for more than a few seconds. I pulled three of the spark plugs and they are pretty fouled but not sure if it's by oil or something else. They clearly need replaced, but nevertheless this problem seems to be oil related.
I used Valvoline MaxLife synthetic blend 10W-40 and a Fram filter. Would synthetic cause this, or what could it be??

[StudeRich]

Do you have Power Brakes on your Truck? It is possible to draw Brake Fluid into the Engine causing what you are experiencing.

The other thing that can cause a non-Oil burner to smoke Blue smoke is to have a Carb. running too rich washing the Oil off of the cylinder walls and burning it.

I would hate to think that good piston rings would not be able to control oil burning with fairly light weight, possibly stickier Partial Synthetic Oil.

Were you using straight 30 Wt. or 20W-50 Oil previously?

Caution: It is not a great idea to ever remove a Thermostat without replacing it. Because initially it will appear to run cooler, but without some restriction the coolant flows too fast for proper cooling of all of the components causing "Hot Spots" and possible damage to critical Engine Parts.
I would install a 160 Degree Stat and a New Gasket and check the Outlet Casting for corrosion especially UNDER the Top Radiator Hose and replace as necessary.

Also check that you have a Spring in the Lower Rad. Hose to prevent collapse.

[mmagic]

I used Valvoline MaxLife synthetic blend 10W-40

That's what I run in my Champ.

[RadioRoy]

You should reconsider the thermostat. Cast iron engine blocks do not like to have their temperature swing too rapidly or too far. The thermostat is there to warm the engine up quickly and keep it at that temperature. Your vapor lock can be solved in other ways.

[Mike Van Veghten]

Don't know how to figure this type problem without a coupla tests...but "no"...ANY...mix of base oil will not cause an engine to go bad overnight...!
If you think about it...kind of-a silly question.

Rich has a couple of ideas, but again, the oil on it's own...is not your problem.

Mike

[StudeNewby]

Do you have Power Brakes on your Truck? It is possible to draw Brake Fluid into the Engine causing what you are experiencing.

The other thing that can cause a non-Oil burner to smoke Blue smoke is to have a Carb. running too rich washing the Oil off of the cylinder walls and burning it.

I would hate to think that good piston rings would not be able to control oil burning with fairly light weight, possibly stickier Partial Synthetic Oil.

Were you using straight 30 Wt. or 20W-50 Oil previously?

No power brakes. Not sure what oil was run in the truck previously, but I may be able to find out.
Interesting that you mention the carb. I noticed that it is leaking, though I would not THINK that is related...

[JoeHall]

Check to see if the oil level is overfull and/or smells like gasoline. If you are running a mechanical fuel pump, it may be puking gasoline into the oil (due to ruptured diaphragm).

I went to electric pumps in the late 1980s, and never looked back at mechanical ones.

[GinettaG12P]

More likely gas than oil. About the thermostat...put a pot of water on the stove and drop the thermostat into it. You should see the thermostat open before the water boils. If the thermostat is still closed when the water is boiling, fish it out of the pot and throw it into the trash.

[JoeHall]

More likely gas than oil. About the thermostat...put a pot of water on the stove and drop the thermostat into it. You should see the thermostat open before the water boils. If the thermostat is still closed when the water is boiling, fish it out of the pot and throw it into the trash.

You can put a meat thermometer in the water pot, and measure when the thermo begins to open and when it is wide open. That will determine if its any good. Sometimes they will pass this test, but still stick once in a awhile. If in doubt, toss it out.

You can run with or without a thermostat there in NC during the summer; it ain't gonna hurt anything, but in winter the heater will not get very warm.

I understand your encouragement in getting rid of vapor lock when you removed the thermostat. But it should run year round with a thermostat, and no problem. When I lived in the desert southwest, I ran 195 thermostats in the Studes, year round; engine temps were often 200-210, and its gonna vapor lock at those temps, with or without thermostat. I just learned to deal with it.

Now days, with EFI, the vapor lock saga is just a (bad) memory

[StudeNewby]

I hear and obey with the thermostat, guys. I like the idea of a 160, Rich, will do.
To address some of the other concerns:
--I'm detecting no gas in the oil that I am aware of.
--Not overfull of oil. It's between the marks.
My next step is to get a new set of plugs. Might be a few days before I get a round tuit due to holiday travel. Keep the suggestions coming and I will let you know what happens.
BTW, thanks for all the help you guys provide here. I really appreciate it.

m

[jackb]

...was advised to pull the thermostat in my '64 convertible when it was running summer hot by an old Stude mechanic. I was relocating to Texas and had daytime temps ~ 100 degrees. Car would run around 200 while driving and would boil over for rest/gas stops. Good ole boy in Texas told me that was the worst thing to do: He was right. I eventually had to bore the block .060 to straighten out the cylinders... especially #7. If you find your truck runs hot with a good thermostat perform a search and fix it....

[Bud]

Don't run the engine without a known good thermostat as the thermostat not only controls the coolant temperature, it also restricts the coolant flow through the system. The restriction is necessary to allow the coolant time to pick up the heat from the block and heads and transfer it to the radiator. I've used 180 degree thermostats in Studebaker engines for more years than I care to remember and never had a problem with vapor lock. I recommend looking at things like leaking head gaskets, cracks, sludge in the water jackets, ignition timing etc. that could cause the fuel system get hot enough to vapor lock. Bud

[DEEPNHOCK]

Removing the thermostat can cause the coolant to go through the system too fast, and not conduct enough heat away to cool things properly.
At the very least, gut the thermostat, but leave the plate in there as a water restriction.
Better yet... Run a fail safe thermostat.

http://www.motoradusa.com/fail-safe-thermostat/

(copy)

[StudeNewby]

*Note to self: Pick up a thermostat...STAT!*

[JoeHall]

If you are getting enough oil into the combustion chambers to foul plugs, and it is not due to gas in oil, it may be related to having woke the engine up, after a long sleep. If sitting for years, the valve stem seals often become harder than ever, and begin to let oil past the stems; the intakes are of the most concern. If it smokes under load, that points to intake valve seals. It could also mean someone left the oil baffles off, upon re-assembly of the heads.

Also, if the cylinder walls accumulated surface (or worse) rust, the rings may have been damaged in running the motor again, and no longer sealing properly. If it puffs smoke after a few seconds of deceleration, that's a sign the oil rings are shot. If it smokes out the breather caps under high RPM or high load, that's a sign the compression rings are shot. (Often cannot see the smoke, but the inside of the vehicle will stink with oil fumes.)

Either of the above would require some dis-assembly. Valve guide seals can be replaced in a couple of hours, removing only the plugs, valve covers & rockers. Rings require head and oil pan removal, but can be done with motor still in the vehicle.