Over temp

[Red36LC]

I need some help with a continuing over heating problem. The flathead and radiator were drained and dry when i got the truck in June. I've changed all hoses and water pump. I have flushed and back flushed several times. It is not a gauge problem but actual steam out the overflow. No matter what % coolant/water I use after a few minutes of road time it is puking. Anyone had this problem?

ps.

The thermostate has been removed

[Rusty_OToole]

There is a coolant distribution tube in the engine. If it gets rusty or clogged up, overheating and uneven cooling results.

The tipoff that something is amiss, is that the back of the engine is a lot hotter than the front. The cooling water streams up the front of the motor and never reaches the back cylinders.

If this is the case, you have to take out the water pump, fish out the tube from behind it and put in a new one.

Cleaning the mud out of the water passages at the same time doesn't hurt either.

[hchris]

By puking do you mean the coolant is being pumped out of the radiator as opposed to just boiling out ? in which case you might want to consider a head gasket leak

[DodgeKCL]

You have a blown head gasket. Been there ,done that. When you take the head off to replace the gasket, take the head to your friendly machine shop and have it leveled. Tell him the age and some what rarity of the head and ask him to keep the removal of metal to the absolute minimum.
You must level the head before replacing the head gasket. I made this mistake on a '33 engine and it drove me nuts for weeks because I just knew I had found the original problem BUT the 78 year old head was warped and it ,NOT the head gasket, was causing the problem. It still kept blowing hot combustion gases into the water jacket even with new gaskets. Actually thought the problem was a steel gasket I had and put the car 'on the shelf' while I found a copper gasket. Everybody said steel head gaskets are no good.
Nope! More wasted time. Until after several discussions with other DIYs I took the head in and got it 'flattened' as they told me that was my real problem. Problem solved.
Don't forget to look up the correct sequence for tightening down the head bolts. "From the center bolts/nuts out to either END of the head. From the center bolt/nut out to either SIDE as you go to the ends. Re-tighten at least 3 times over several weeks. Same sequence"

[Red36LC]

Thanks for all of your help. In reference to "puking" I mean with the cap on it blows out the over flow pipe. With the cap off it boils out the radiator fill. I'm not sure about the temperature of the engine at front and rear. I checked it with a meter and don't think there was a significant difference 10 degrees maybe. Can't remember right now. If I had a blown head gasket wouldn't there be white smoke (steam) out the tail pipe?

[DodgeKCL]

Possibly but I never thought to look at the time. What happens is the explosion pushes hot combustion gases out into the water jacket and literally boils it. And unless you've had this fault before it can drive you nuts because you keep looking for the 'normal stuff'. And none of it helps.
It wasn't until I was told that I would have to have the head shaved and flattened did I finally solve the problem. I've been troubleshooting on my own,DIY style, for 50 years and this was one of the most difficult problems I ever fought especially since the 'bad' steel head gasket was a 'red herring'. It would have been quite alright if I had had the head planed and flattened before using it.
I think our old cars and trucks and are going to need their heads planed down now because of age. They have been around long enough to suffer warping because of heating/cooling cycle.
By the way, I don't know if this is always true but the consumption of antifreeze, which burns because of it's plastic base, usually cleans the spark plug's porcelain in the offending cylinder bright white. And really cleans the overall tip area of the spark plug like it has never been used in an engine.
I don't know if this always true but you might check. It will be obvious.

[Red36LC]

Thanks again. I'll let you know.

[Rusty_OToole]

I had a similar problem on a flathead six DeSoto. It turned out the top tank of the rad was full of mouse nests. When they drained the rad they must have left the rad cap off and the mice built nests in the rad. It was all chewed up brown paper shop towels. When I took the rad off and cleaned it out I got a mess of wet shop towels about as big as a football.

Water could go through the rad slowly but as soon as you hit the road it would boil over.

This is not likely your problem if you have cleaned the rad but I thought I would put it out there.

[Red36LC]

Back again, it was the radiator. It was partially plugged with rust and stuff that wouldn't flush out. Had a new core made. I drove it to a car show 30 miles away today with no problems. I changed the water distribution tube while the radiator was out. And flushed the block a lot.