Check for blown head gasket?

41panelmark

41panelmark

Well-known member
Guys I am having an overheating problem when the temp outside is over 60. anything over that and the engine temp on the gauge and using a laser goes way up and it starts to drip antifreeze out the over flow worse at higher speeds.

I have no signs of coolant in the oil nor oil in the coolant. Very little coolant is lost since I shut the motor off soon after and let it cool so the level is very close to where it should be.

Do I have a head gasket problem or?

This engine is has less than 3K miles on it and has new pumps, the truck has an n.o.s. radiator. I did buy a Walker radiator which I plan to install but thought I would get some ideas from the Banrner's.

Distributor is a rebuild from Bubba's.

Any thoughts would be appreciated.

thanks guys.
 
First of all what's way up? Without specifics this turns into a guessing game of which its doubtful of getting a correct answer. Your temp range should be anywhere from 160-195. If you are having a coolant burb, thats common if you are running your engine at higher road speeds above 50 mph. So back to the original topic what temperature does the lazer pointer say the coolant is in the radiator tank?
 
Remove the hoses from the heads and fill the heads with water then remove the belt. Start the engine and look for bubbles in the water necks .
 
Since you have the laser thermometer take the temperature on the center neck of the heads just below the hoses. This is the only real important temperature to worry about. Hold the gun the same distance, same angle and at the same spot each time.
Is your radiator set up for a pressure cap? If the over flow tube comes off the top of the upper tank a pressure cap won't work. If the tube comes out from the filler neck a pressure cap will work. Without a pressure cap or Skips 3 lb pressure valve on early radiators with no provision for a pressure cap you will never get good cooling. To get good cooling you need to fill the radiator up into the filler neck, more water equals better cooling. More water flow also equals better cooling. Any restriction in the system such as restrictor washers or modern thermostats which have small flow openings cause the engine to run at hotter temperatures in hot weather. If your temperature never gets over 200 you should never lose any water at least up to 80 MPH. I drive my old Fords with Columbia rears at 65 to 75 MPH for 10 to 14 hours straight in 95 degree temperatures and never add any water for 6 months. You need a pressure cap that seats down on the bottom seat in the filler neck. No seat on the bottom means the pressure cap don't work and will let water out the over flow. If you really have a compression leak that will open a working pressure cap and allow water to escape. All most ALL old Ford pressure caps don't seem to hit the bottom seat in the filler neck so you get a loss of water. Attached photo shows the rubber gasket I use to make the cap seat. You don't want this gasket to thick or the pressure cap won't release at it's 4 lb rated pressure. Notice how clean and shinny the tubes and top plate are. This is from high flow pumps and Barr's granular aluminum stop leak. Over a long period of time the aluminum granules clean and polish what can be seen, I don't know if it cleans the tubes and other parts?? G.M.
 

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If this is a V-8 flathead, I would expect only one side to overheat due to a blown head gasket. I think it would be unusual for both head gaskets to go bad unless they were not installed correctly.
I have a blown head gasket in my 50 Ford that caused the drivers side to overheat when going up a steep hill when the engine was still cold. My temporary fix was to drill a hole in the thermostat on that side to allow exhaust gases to escape, and let water get to the thermostat to open it. That was 5 years ago, and I still have to change the gasket.
 
Remember the thread(s) I had going last summer, as soon as the outdoor temps got over 60 I started having overheating at highway speed with plenty of air going through the radiator. Rebuilt engine, recored original radiator, Skips pumps and distributor, and hi flow thermostats. I even pulled the heads, even though I got no bubbles in the water necks with compressed air in the cylinders.

Turned out I needed more radiator and bought an aluminum aftermarket radiator, it's been fine since. Even drove down to the Denver All Ford Day in September last year in 90 degree weather and had no trouble!
 
Dick is right, lets get the temp readings a highway speed and then go from there, right now all we can do is guess and that solves nothing, a lot more info please
 
Sorry guys, I forgot to give the temps and such. Also good information so far. The engine is a flat head and it is stroked and has higher compression than stock. Yes it has a 4lb cap and only dribbles when it gets very hot which by the way is 230 and up. I will take some readings next chance I get and report back to all of you soon.
 
Use a exhaust gas analyser to check for exhaust gasses in the coolant. Remove the radiator cap, and place the 'sniffer' where the cap was. Check the readings - in PPM,
should be less than 10. Rev the engine up to 2000, and check as the RPM's increase,
if you get readings that build, good indication that your getting exhaust gasses in the coolant, and you have a bad head gasket and possibly a crack as Merc mentions in his post. Replace the head gaskets and be sure to have the heads surfaced - usually a few thousands of an inch is all that is required to clean them. Mine were in the .005 - .007 range.
Ken's idea will show you which side the exhaust gases are coming from. I'll take a guess and say it is between 2 and 3, and likely a crack around #3 exhaust valve.
 
Back with information

I installed a Walker radiator and drove it today in the heat, (90 degrees +/-). The new radiator helped for a while but eventually it pushed the "H" on the gauge. Keep in mind I was traveling at speeds between 0 and 40 mph. Made it back home.

I stopped a few times and took readings and for the most part they did not fluctuate much once the engine got hot. Most readings were even on the heads at all points 236 to 240. Lower hoses were 195 to 200. Hoses at the middle of the heads were 210-212. Hoses at the top of the radiator were 197, all of these seem way to hot to me. When I shut if off every thing went up even more and stay that way for a while.

Ideas?
 
Re: Check for blown head gasket truck heads?

Next thing to check is the compression. Maybe the heads have been milled to far, if it turns out the compression is to high should I find a set of truck heads to bring it down to help with cooling?
 
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