Boils over

[jwaldrich]

Running my car down the road and if I run 45 plus MPH it will boil over but then quickly cool right back off and eventually boil over again.

First thought was bad thermostat. Tricked me. Doesn't have one. Searched the threads and I don't even have that square black adapter to accept a thermostat.

Car runs great, not running too rich or lean. Did this when I first got the car and the weather was NOT hot.

Your thoughts?

[Jim/GA]

Sounds like classic plugged radiator to me.

Do a search on overheating, boiling over, etc. in FB and you will find a bunch of similar threads.

...

[jwaldrich]

I was thinking that but I REALLY didn't want to...

[Jacksonlll]

Your radiator is plugged just like all the other A's that overheat. If you can't drive 45 mph for 10 min, then look hard at the radiator. Look at this video. https://www.youtube.com/watch?v=Ug01...rIa0r_fFQcz4R0

[Mitch//pa]

not everyone uses the thermostat adapter... many are inside the upper hose undetected....just sayin

[Ron W]

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Is it boiling or just blowing because it is too full or the overflow is plugged? Ron W

[jwaldrich]

Originally Posted by Mitch//pa

not everyone uses the thermostat adapter... many are inside the upper hose undetected....just sayin

Didn't see one there either as I have the upper hose off. I suppose there could be one there I didn't notice but more likely it is time for a new radiator.

The only part about pulling out an engine I DON'T like is pulling that no good #$$%!$#@$ radiator!

[jwaldrich]

Originally Posted by Ron W

Is it boiling or just blowing because it is too full or the overflow is plugged? Ron W

That is a good question as I have wondered why I have seen nothing coming out the overflow tube and it is where it is suppose to be....

Guess I'll go run a wire down it...

[Ron W]

If you don't see steam, it's probably not boiling. Ron W

[jwaldrich]

Originally Posted by jwaldrich

That is a good question as I have wondered why I have seen nothing coming out the overflow tube and it is where it is suppose to be....

Guess I'll go run a wire down it...

Not plugged so I guess the radiator is.

[glenn in camino]

Time to have your radiator rodded out or recored.

[1931 flamingo]

If the water isn't going down the o/flow tube where is it going??
Is it coming out around the rad cap?? Repl gasket.
Have you ck'd timing??
Where is your spark lever??
Do you have a temp gauge to verify it's boiling or just finding it's level??
How much water/liquid do you add after it "boils" over""
Paul in CT

[1crosscut]

John have you actually checked the temperature??
Get a cheap dial meat thermometer from the grocery store or the kitchen and actually test the water temperature.
Maybe you are not over heating but just too full on water.
Check the simple stuff first.

[ian Simpson]

My 1928 Tudor with a radiator that has less than 500 miles on it likes to fake boiling over when driven over 45 mph. It goes the whole nine yards with anti-freeze bubbling out around the radiator cap and dribbling out the overflow.

Just an over active water pump setting the correct coolant level in its own way. Did a 60 mile run on Sunday with the temperature around 35 centigrade (95 Fahrenheit), bubbled and spit all the way. Checking back at home showed less than a cupful of anti-freeze gone.

Measure the temperature, do not assume the worst.

[Bruce Adams]

Big question is whether it is BOILING OVER or just PERCOLATING since if the radiator is full above the baffle the pump deposits more water into the radiator at higher speeds than it pumps into the engine so it bubbles over but is not over 212 degrees. Check the radiator with an infra red thermometer like you can get at HARBOR FREIGHT for under $30 (or a meat thermometer for $5 placed in the radiator) and while you are at it check the radiator for COOL SPOTS which means it is not passing water through the cool spots.

[jwaldrich]

Harbor Freight is 100 miles round trip. I may have to steal the wife's Candy Thermometer.

It could be over full but methinks it is more than that.

What made me think it was a stuck thermostat was the way it acted ( MotoMeter). Went HOT, I slowed down and it DROPPED.

[Brentwood Bob]

Maybe a blockage at the thermostat.
Bob

[jwaldrich]

No thermostat. I would run down the road for 10 miles or so and then the moto-meter sky-rocketed to hot and water came out the cap.

It has done this since I purchased that car last year but I have had so many problems with this car I haven't really looked at this. The last time it did this I specifically looked for water out the coolant overflow tube and nothing! I truly expected to find a plugged line but it wasn't so I assume I just missed it.

Frustrated Model A owner here. When I got into Model T's a friend told me to put a new gas tank and radiator on any Model T I bought and that would immediately solve 99% of it's problems. Maybe the same is true with A's.

[Jim/GA]

John-
Do you have a grease fitting on your water pump back near the engine (on the packing nut end of the water pump)? If so, hit it with a shot of grease.

If you have water pump packing inside the nut, snug up the nut. Add some packing if it needs it. (Does not apply to a "leakless WP".)

Then go drive it at 45 MPH, see if it improves any.

[jwaldrich]

Originally Posted by Jim/TX/GA

John-
Do you have a grease fitting on your water pump back near the engine (on the packing nut end of the water pump)? If so, hit it with a shot of grease.

If you have water pump packing inside the nut, snug up the nut. Add some packing if it needs it. (Does not apply to a "leakless WP".)

Then go drive it at 45 MPH, see if it improves any.

I think I have a leakless waterpump. There are a pair of grease fittings but both are dead ends. I guess this is for "show" points but I sure cannot get any grease in them!