Strange coolant "spew" issue

[66sprint6]

Just put a low mile 5.0 in my 90 coupe, new cam, dual roller, waterpump, gaskets, radiator, taurus fan etc...fired up nice, idles well, runs strong but I got a goofy problem that concerns me. When we were puttin coolant in the radiator waitin for the "burp", instead of burping it gysered out all over the driveway, just POURed out. I filled it up and it would sit there, kinda turbulent then it would rise until it was pouring out again...seems like it does that then the thermostat opens and you can see the coolant level lower into the rad. and stop spewin. I finally got it to stop, capped it and it went about my life. Car NEVER even comes close to gettin hot, but the heater doesnt blow very hot at all. Took the cap off tonight, same deal, spewin all over the danged place. Theres no oil in the coolant, no coolant in the oil, no smoke in the exhaust, passed emissions just fine, but its still bubbling in the radiator and eventually spews when the caps off...doesnt do it when the cap is on...sheesh, anyone know whats goin on?
Thanks guys, sorry this is so cluttered up but its hard to explain
Matt

 

[Maryland Stang]

It still has an air bubble in it. I ended up drilling a 1/8" hole in my T-stat to get rid of the same exact problem. It's not showing hot because there is no coolant touching the temp sensor inside the lower intake. Trust me, it is getting hot, very hot.

 

[WHT306]

YEAH SOUNDS LIKE AIR IN THE SYSTEM. HERE IS A WAY TO CURE THAT.

GO TO THE PARTS STORE AND GET THE PRESTONE COOLANT FLUSH KIT FOR LIKE $5-$8 TAKE THE TEE OUT OF THE KIT

TAKE ONE OF THE HEATER HOSES ON THE FIRE WALL USUALLY THE HIGHEST CUT IT IN HALF
PUT THE TEE IN . IT HAS A CAP THAT SCREWS ON AND OFF WITH A SEAL.

NOW WHEN YOU FILL YOUR RADIATOR REMOVE THE CAP AND IT LETS THE AIR OUT OF THE SYSTEM, AND WHILE ITS RUNNING UP TO TEMP YOU CAN STILL BLEED AIR OUT BY JUST UNSCREWING THE CAP A LITTLE!!!! NOT ALL THE WAY JUST ENOUGH TO SEE COOLANT RUNNING OUT OR AIR BUBBLES.

 

[tiptop]

Its either a bad headgasket or a cracked cylinder head

 

[66sprint6]

Looks like it may have just been the thermostat. When I put this motor together, I totally overlooked replacing the thermostat. Swapped it out today, drilled a 1/8 hole in it like said above and all seems pretty well. It let out some wicked bubbles and then calmed right down, never got as violent as it did before. Heater still isnt hot at all but its cold outside and the car runs super cool. Aluminum radiator and cold air outside must be workin pretty well while drivin then the taurus fan takes over when Im idling. Wish I could figure this heater deal out tho...its a new heater core since about a year ago and worked well before this motor and radiator...I checked it and its not clogged and both lines feel hot...hmmmm. I was hoping it wouldnt be a headgasket or intake gasket as it would hurry my plans of heads/intake to compliment the cam but Im really thinkin I got it figured out. The car runs AWESOME, no leaks, no smoke, gauge reads cool, you can watch it go up at idle, fan kicks on and temp goes down so I know coolants gettin into the motor...on the interstate it stays cold...just no heat in the heater. Wonder if its somethin to do with the heater itself...
Matt

 

[influence]

Issues

I just had the somewhat same problem I got an older new motor as well and the car constantly ran hot, real hot. Turns out the radiator(Brand New PWR) was plugged so bad (got plugged after putting 500 miles on it) with this and the water pump as well with this goo like mudd crap. Turns out after talking to a few different people if someone ran orange coolant and you use green a chemical reaction takes place and turns to a muddy like substance...so heads up on that to anyone....but the point I was getting to is instead of cutting your heater core hose I made a little contraption for under 10.00. Go to the auto parts store and pick up 2 feet of 5/8 heater hose then go to home depot and pick up(all of this is in the garden section) 2 5/8 barb fittings with regualar garden hose threads on the other side(female) then get a 2 way splitter(as if you had 2 garden hoses from the same spout)

Next unplug heater core hose and put (1) barb on it and then screw it on to the 2 way adaptor. then take the 2' foot of heater hose you bought...barb on one side screwed into the splitter and the other side plugged into the heater core barb. plug your garden hose into the top of the 2 way splitter.

Turn on your garden hose and go to your splitter in the car and open each valve..tada you have an open and close valve so when your bucket is full you shut it off...dump the excess water and then begin again.

Hope that helps

 

[66sprint6]

Awesome stuff guys, thanks for the info. Still no heat inside the car, gonna take and have the motor/radiator flushed see if itll help any. Got a scare today tho. Noticed the car runnin a little rougher than normal at a light, turned off the radio to hear the LOUDEST metal bangin noise ever. She drove fine, but was missing and had the noise. Pulled the plugs, nothing, they were perfect. Took off the upper intake and the passenger valve cover and WALLA...broked rocker bolt. Got her fixed and now she's runnin nice again...now back to the bubble LOL
Matt

 

[EMW150]

Awesome stuff guys, thanks for the info. Still no heat inside the car, gonna take and have the motor/radiator flushed see if itll help any. Got a scare today tho. Noticed the car runnin a little rougher than normal at a light, turned off the radio to hear the LOUDEST metal bangin noise ever. She drove fine, but was missing and had the noise. Pulled the plugs, nothing, they were perfect. Took off the upper intake and the passenger valve cover and WALLA...broked rocker bolt. Got her fixed and now she's runnin nice again...now back to the bubble LOL
Matt

The heater core in my '87 used to do the same thing. Take the hoses off the heater core and get a spare hose and backflush the heater core by itself in addition to flushing the rest of the system. I'll bet it's full of junk.