Issues filling cooling system

I'm trying to fill the coolant system after changing the rad etc with the rad cap off to burp the system.

With the cap off whenever I turn off the car coolant is flying out of the open rad cap! Anyone have any ideas

 

Is the car stable to operating temp? (thermostat open).

And how long is the water flowing out the filler opening? Is is like a geyser, bubbles and coolant, or just coolant?

I have seen several causes.

Hot block water, but thermostat is not open yet, and with no pressure, the water boils creating steam in the block and that results in the "geyser" effect.

A blown gasket can do that, but that much blow-by you would likely have other obvious signs. Steam from exhaust pipes, hydro-lock and poor running.

Incorrect pulley size/speed can cause some pressure to build and if there is air in the system, it can get compressed, then "surge back" and out the filler.
(water pump spinning too fast). But should not as obvious at low RPM.

I drill a 3/8 hole in the thermostat to help with trapped air and filling issues, and fill cold, wait a few minutes then add as needed, do this a few times, and also manipulate the upper hose to get trapped air out. Start the car, and let it idle, cool down, then open and fill. Usually that's all it takes.

An inch "air gap" is fine when cold, as long as the down tubes have a couple of inches covering.

 

Drill hole in stat....1/8-3/16in.....that way it will burp itself as it circulates. Otherwise it doesn't circulate until stat opens then it slams shut when it gets the cold water then cycle repeats.

 

Thanks for the reply guys. I removed the thermostat housing and thermostat to fill the motor with coolant and then re tried. When I did I drilled a 1/8" hole to help some air escape

I was trying to burp it running but it was spewing coolant all over the motor and electronics when it would burp. Add to that I think my mech temp gauge is taking a $hit because it was reading some really scary temps that were causing me to turn the car off out of fear. The FITECH was showing much lower temps but I didn't want to chance damaging the motor.

When I would turn the car off it would dump half the rad out of the top of it.

I'm sure it's just a trapped air issue but the temps it was showing on my mech gauge were scary causing me to shut thinhs down before completing the bleeding process.

Maybe use one of these with a lid to fill it?

Could the insane heat temps be being caused by steam on the sensor not coolant

 

Thanks, I intended to type 3/16" not 3/8".

 

most thermostats do have a small hole already drilled.

 

Interested idea on the pipe plug on the water pump. But isn't the thermostat higher ?

 

I've used one of those screw-on mega funnels that helps minimize splashing -- but I don't recall it being an overly messy effort. It sounds like when you shut down the engine the t-stat actually heats up (as the water temp rises a bit when the pump is no longer spinning) and pops open -- pushing air out.

 

Could be right Bostoncat. Issue is how to I resolve it? And what would be causing the temp gauge to read 60* higher then it should

 

Ok @72buicklark lets suppose the intake is still air bound -- could the steam at the top (near the temp sensor) -- read 60 degrees hotter than the coolant? I like Jason's idea...

 

I find it easier to have a small hole in the thermostat and remove the heater core hose and fill thru the hose with the radiator cap off. I fill it thru the heater hose till if starts flowing out the top of the radiator then cap that and continue filling till it starts flowing out the heater core nipple . Then push the hose back on the heater core. System should be filled .

 

I'm not running any heater lines.

I picked up a fancy no drip funnel to see if it aids my venture any..... may just make it splash out higher who knows.

As for the High temp reating I'm PRETTY sure it was the steam because when I hit the thermostat housing base and several parts of the motor with my infrared thermometer it was about 75* cooler

 

You might have a waterpump manufactured exclusively for use in the southern hemisphere. Hopefully some of our Aussie guys will speak up.

 

What is the "etc." you changed with the radiator?

What has changed from the last time "all was right in the world"?

Radiator. New, used, who manufactured it. same flow (cross/down) number of tubes, aluminum etc.?

Run it without the t-stat and see what the temp reads, and if you see any difference in the "burping/belching" of water.

Have you had overheat issues before?

If so, are the heads original or different, as some water passages are not lined up the same.

You will have to drain and pull a hose, but might want to check the impeller to see if it is rotating with the pulley.

And some pumps are reverse flow, if you changed that (in the "etc." ).

Sometimes it is difficult to troubleshoot over the phone, internet, radio.
(an old thing back in the day in the Air Force, was "no troubleshooting over the radio", in maintenance.)

Best to put hands and eyes on the problem, so it is a bit of a challenge, and sometimes folks are "looking" at things from different perspectives and experiences and the lack of "being there" and knowing what has or has not been done since it last worked.

But, it can be figured out.

 

Heads are aluminum and have been on the car for 2 years without issues. Same as the water pump and t stat.

Never had overheated issues in the past.

New 2 core cross flow rad with aluminum shroud and electric fan with overflow. I picked up one of those funnels to see if it helps me out any today