Radiator Boil Over

[Tinster]

New radiator and cap, new hoses, new coolant fluid after
recent flush (twice), new thermostat, new temp sensor,
new sensor wire and new temperature gauge. Old man
installed all parts.

Temp reading 160ish in the garage while I set the timing
and carbs. Temp climbs to 190* during the tuning process.

Shut down the engine and almost immediately old faithful
erupts from under the radiator cap. NOT into the overflow bottle as usual.

So wuz up with this latest bugaboo Crypty has handed me?
I think I need David back to scare some sense back into
the car.

thanks,



d

 

[AweMan]

Holy Smokes Dale:
I`m guessing here, but ..... are you sure it is the right LB. pressure cap? Did you campare it to the old one {physically} did it look the same? {same legnth,& diameter.} Are you positive you replaced the thermostat in the correct orientation? {it is easy to get them upside down} Other than these things, Possibly the new cap is not functioning correctly. It is very possible that the new cap is defective.
Boiling out the cap and not into the overflow makes me very suspicious of the cap.
Put the old cap on and see if you can re create the scenerio. If not then a different new cap may be in order.
Just some ideas.
hope you resolve it {I know you will}
Kerry

 

[Tinster]

Hey Kerry-

It might be my bad afterall.

A while ago I removed the cap to add fluid.
I noticed the cap was not in it's full locked
down position.

I drove the car 2.6 miles after warm up and the overflow
bottle got filled with hot water like normal.

But this was a wake up call that I need to add a spare
radiator cap to the emergency repair parts I carry in my
trunk. I don't carry any spare radiatir hoses because mine
are all brand new. I read they often fail. So maybe a set
of spare radiator hoses in my trunk as well.

I am still amazed at the sheer number of spare parts that
must carried in the trunk of these cars in order to drive
from point A to Point B and get back home without calling
a tow truck.

Good call on the cap-Thanks.

d

 

[TR3driver]

Rad caps virtually never fail; and when they do you just fill the radiator again and drive home. Not an essential spare, IMO (and TR6 rad caps are much easier to come by than TR3 caps).

Puking a bit under the circumstances you describe is borderline normal; probably wouldn't have puked at all if the cap was tight and holding pressure. What happens is that there is a lot of heat still stored in the cast iron between the water jacket and the cylinder/combustion chamber, and when you shut the engine off there is no longer coolant flow to carry it away. So, it heats the water to boiling. But, boiling the water carries heat away, plus the bubbles force some circulation bringing cooler water into the hot spots, so only a small amount of coolant is lost.

I'd be more worried about why it got that hot in the first place. Are you sure the thermostat is 185F or less ?

Randall

 

[Andrew Mace]

I'd be more worried about why it got that hot in the first place. Are you sure the thermostat is 185F or less ?

I had the same thought. I can't imagine why you'd need anywhere near that "hot" a thermostat in the Caribbean! Meanwhile, was this the first "run" of the engine after all that cooling system refurbishment? Could have been as simple as a bit of an air bubble or incomplete fill, and then possibly compounded by a loose cap?

 

[Tinster]

Brand new 160* thermo. Tested with IR gun when installed.

d

 

[AweMan]

Engine coolant boils more readly when it is under NO pressure. That is the reason radiator caps are designed to hold X amount of pressure before releasing to atmosphere. On NEWER {hotter running} engines, remove the radiator cap and drive for an extended legnth of time and it will result in the coolant coming to the boiling point in a hurry. Continue to run the engine in this manner will result in a blown head gasket.
It is imperative that you have the proper LB radiator cap for your specific application. And that it is in working order.
Ture ... on "Older" model cars {just how old I won`t specualte} the cooling system MAY not be as sensitive to the pressure/no pressure condition. Never the less there is a specific pressure requirement for a reason. Radiator caps seldom do fail, Having said that, they do however become weak over extended time {due to the hot/cold scenerio} and should be replaced periodicaly. Or at least tested to ensure they are holding the required pressure for your application.

 

[Deleted member 7471]

Sorry to hear about the latest woes Dale, but that looks like authentic tasty PR cuisine in the photo. Would you care to comment on the menu?

 

[Tinster]

Gladly: You guessed it. Local cuisine as authentic
as it gets. A non-tourist place we keep hidden waaaay
up in the mountain town of Guavate.

In Guavate they have one single industry. They cook
spit roasted whole pigs and turkeys for immediate
consumption. The "restaurants" are called Lechoneras.
There are maybe 30 different Lechoneras in Guvate.
The photo was taken at our favorite "Los Pinos".

David is eating fresh roasted pig, yellow rice with
gandules peas. He has a side dish of small, green banana
species boiled in garlic water. A side dish of dark yellow,
sweet platain cooked in butter and sugar. A plate of roasted
white sweet potatoes (batatas here) and a dish of garlic
cooked yucca root. Plus potato salad and CAB.

d

 

[RonMacPherson]

The thermostat you put in, was it a 160 degree stat?( A chevy small block fits, so does the gasket) Does it have a bypass hole in the body of the stat(if not drill a 1/16 hole)? Is the stat installed with the spring around the body under the circular flat piece in the engine and not facing upwards? Was the radiator cap installed tightly?

These caps also fit other cars, can't remember which, right off the top of my head, so you shouldn't need a spare.

Did the same thing a few years back to me, when I didn't have the cap on tight, but it puked in my girlfriends driveway, which didn't do a whole lot for the admiration of skills(automotive wise) thing.
Plus, I've been running Gates or Dayco hoses for several years now, no problem. So get a set of good hoses and no spare parts needed.

 

[TR3driver]

Plus, I've been running Gates or Dayco hoses for several years now, no problem. So get a set of good hoses and no spare parts needed.

Amen ! /bcforum/images/%%GRAEMLIN_URL%%/iagree.gif