Boiling coolant

[FullNelson]

I know I need to go and do a block test and pressure test it to eliminate all possibilities.
With that said, the car doesnt over heat, but If its driven over 30 miles, it will start to spit the boiling coolant into the birdcage. Temp sensor reads a line or two below horizontal.
Aside from the obvious BHG(just rebuilt and better not be or the machinist can redo this motor on his penny)
I saw the nipple on the radiator going to the birdcage cracked off and the hose was placed on there in a mediocre fashion, enough to get the fluid to the reservoir, but most likely not airtight. Would this cause some pressure loss and create the boiling fluid?

 

[Dirgle]

If it's not air tight then possibly yes. After the car is turned off and the engine cools down and fluid is typically drawn back in to the radiator through that hose. If it's not sealed then air can get in to the radiator, and cause boiling like your describing the next time you warm up the car.

 

[Heavy D]

this happen to me, i had my a/c on going 90 mph and next thing i know i was 3/4 away from red so i shut the car off let it cruise untill i pulled over, and spitting antifreeze out of the bid cage box, it was because there was a bit of air in the radiator, i let all the air out and now its not doing it no more. but im going to get another radiator cap just to be safe

but doing test wouldnt hurt it

 

[mkiiichip]

Test and inspect your rad cap.

and you need a radiator.

 

[FullNelson]

I was thinking I could just drill and tap it for a brass 1/8 fitting to barb in the mean time. The gauge just never went above horizontal. IIRC The radiator cap is 11lbs? Correct? How warm would the fluid have to get and then cool to before it would start sucking in air? Would it be possible its miniscule enough that the stock gauge wouldnt really register it?

 

[dubsupra209]

my stock radiator cap says 13lbs

 

[grimreaper]

I havent seen over 198- 200* this year (ac on full, 100* ambient, stop and go traffic for 20-30 minutes) and im currently replacing a leaking MHG. Temp is not the only sign. My stock temp gauge never moves from that tick below half way position...

 

[FullNelson]

Well then ill do the compression test, just hit 1000 miles on motor, and the coolant presure test, and perhaps to be safe, ill see about the chemical test for the coolant to see if CC/oil particulates are getting in there..