Thread: Radiator Overflow help

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I have never had this happen with any of my cars.

The 32 I just bought was running very cool at 160 or so. The guy I bought the car from literally had 100 miles on it and and never really got it hot or in traffic.

I was working on it, while letting it idle in my drive for 15-20 minutes. The temp guage only showed 180 temp. I shut it off and startee to walk away and it started blowing air and a little antifreeze out of the over flow tank AND the radiator cap was allowing (again mostly air/steam) out! The engine did not seem overly hot either!

When I drive the car it runs great at around 160 with no problems at all. This just happened when it sat at idle for 15-20 minuytes.
Right now there is no thermostat in the intake but I plan to put one in.

Thoughts on what may have caused this and what I should try?

Where is the engine temp picked up from? Intake or head? T-stat maybe stuck...fans was not on..radiator cap not tight?

put a thermostat back in it ,run it for a awhile. put a new rad cap,lever type ,pop it a couple of times and let the air out ,then see what you got.

A couple of things come to mind, as your running the engine, whether driving or idling, your getting enough cooling air through the rad, and water movement through the engine to keep the temp down. But, when you shut it down, the heat in the engine will transfer to the water, (as it should) since there is no cooling taking place, (no air over the rad, and no longer water flow) the coolant in the engine area is over heated, and boils. Either you have trapped air in the system, (as has been mentioned earlier,) and/or a rad cap that isn't rated high enough in lbs. pressure before it will releave. As an example, some foreign cars have a electric fan wired up live all the time, when they shut off you may hear the fan come on for a minute or so, and even cycle a couple of times, because the water has absorbed the engine heat and tripped the fan switch. They have the same thing happening as you described, they also have a 8 or 9 lb. cap to help control the temp and overflow. Sniper

My interior engine temp pick up is in the drivers side/rear part of the intake. My Spal fan thermostat switch is up at the intake by the intake thermostat.

The radiator cap that came on the car is a 20 pound cap! i know that is a lot as I normally run around 16 pounds. That also blew my mind that a 20 pound cap did that.........Maybe it was bad! We will soon find out when I replace with a new one.

By the way, on my radiator I can't tell how full it is due to the angle of the fill neck at the top. What is the capacity of most radiators on a 32 ford?

Try and find a local tool guy..Snap on,Matco..and look for a funnel called teh "Spill Free Funnel" Works great for filling radiators and no spilling any fluid

Once you shut off a running engine the water in the radiator will heat up a little because it's absorbing the engine heat. This may be the source of additional pressure.

If the radiator is overfilled, it may be expelling the excess as the radiator usually finds its own level at normal operating conditions. Get a mirror and check the fluid level.

If it persists, install a coolant recovery system-basically one of those aftermarket aluminum/stainless cylinders sold by the street rod parts houses. I dollar well spent. In my 302 powered 48 Ford, it constantly peed out coolant and I would always have to add some. I installed one of those coolant recovery cylinders and never had a problem after that.

A twenty pound cap sounds excessive???

I am having the same problem with my Cobra. At about 30 MPH and above it runs cool as a cucumber—160 degrees with a 160 degree thermostat but in slow traffic or at idle it gradually increases the temp to where it would boil over if the engine continued to run. When the engine is turned off and the electric fan is on, it cools right down without problems. The infrared thermometer shows that there is about a 40 degree gradient between the radiator top return fitting and the bottom supply to the water pump which one writer said was normal. (By the way those IR thermometers are the greatest things since nylon tie straps. ) The IR thermometer also shows that the dash temperature gauge is reasonably close.

Overtime I have found and fixed a backward head gasket—it’s a Ford Cleveland, a hole in the return hose and a leaking thermostat housing gasket. None of these repairs fixed the problem.

I have rerouted the plumbing two or three times to reduce/prevent air in the heads, have gone through two water pumps, two radiators, four electric fans including about a 2400 CFM Spal-now a 3400 Zirgo, and an unnumbered amount of different thermostats and radiator caps. I have tried Water Wetter and several different anti freeze combinations. Nothing has worked.

There is a good chance the problem may not be in the cooling system at all. But last week, I talked with the good folks at PRC (Performance Rod & Custom) whose company is about 8 miles north. I wanted to try a triple pass two row aluminum radiator. They recommended a dual pass, with a Spal fan and shroud, and another way of directing the plumbing to reduce the likelihood of air in the heads.

When the unit is in, I’ll let you know what happens. Good luck on yours

Rick

Rick- I had the same problem you're describing with my 63 Nova. Tried different fans, fan clutches and shrouds. Finally put the big $ up for a BE COOL RADIATOR and it helped lots, but in the end I needed more air flow at stopping or very low speeds. Added a dual Spal Fan and it runs 195 at the very hottest of days now. In traffic or cruising inside of Good Guy shows.

Here is my final product that now keeps it cool.
http://s104.photobucket.com/albums/m...nt=Nova007.jpg

Thanks for the information.

That's a very nice looking Nova.

Rick