Wondering about Burping

[oznerol_68]

1968 Bronco
1970 302 Stock not too sure, rebuilt 30,000 or so
3spd
Stock radiatior and fan I believe, it looks like from 68

When Bronco parked and started runs fine, been doing two mile runs, starts to boilover at mile one, and when I get back theres a thumping noise, sounds like from the bottom of radiator or hose, like pressure needs to get out or something,
sometime sounds like maybe pump is dry or the alternator maybe cant tell

Problem started when changed the T-stat to 180 from the 160 I think
No problems before that besides heat lower than now, radiator had a screw and clamp on the overflow hose and had no aux tank

Have aux tank and new 13lb radiator cap now, seen spill into and sounded like air trying to get out of hose on filler neck and cap

Tried to "burp", let run with cap off and boom seem like a huge air bubble behind antifreeze happened a couple times, not too sure if thats right or something else is the problem, wondering is there equalization to air antifreeze mixture or is the excess air or steam being produced come out the filler neck hose

Have watched the flow take place when T-stat opens, like a drop and fill, with the flow going from driver to passenger direction

Temp right now is about 9 with wind chill below zero for sure, still happening to boilover and stuff, so outside temp shouldnt be a problem would it

Read somewhere on here to fill from heater hose to replace lost antifreeze in manifold could that be my only option or did I turn an ant hill into a mountain

 

[Viperwolf1]

Boiling at mile 1 is a serious problem in 9 degree temps. If it wasn't doing that before I would think the thermostat isn't opening. It's pretty easy to get it out of the pocket in the waterneck when installing and it will bind up if you do.

 

[oznerol_68]

If I take out t-stat would that be fine, so does that mean no heat, need to get going soon, running low on water, the mighty bronco is our water hauler, been cold this far along in the season, so would taking out t-stat do any damage? Kinda worried about sound think its coming from pump

wondering how to tell if radiator is fouled up somewhere along,

also wondering how bottom hose is supposed to feel, like pressurized or squishy I guess is how to put it

thanks ahead for any input

 

[Viperwolf1]

If you take it out you won't have much heat for the heater and it won't help the engine either. Like I said, if it wasn't doing that before it's probably the new thermostat. Just try another.

Hoses should be stiff after running as heat/pressure build up.

 

[oznerol_68]

Thanks Viper, I'll bite the bullet and shell out the six bucks, is there a particular brand to get, maybe should just go back to original t-stat 160
is there a special way or process for reassembly to antifreeze behind t-stat or is that whole opening of t-stat and filling from top

I think im ruining my water pump, newbie to the max, lol but not, if you know what i mean

 

[Viperwolf1]

160 is too cold. Get a well-known name brand like Robert Shaw or Bosch and you'll be ok. Checker Auto has a gasket that has adhesive on the waterneck side. It works really well. Place the thermostat in the slot on the waterneck then put the gasket over it. It keeps the thermostat from moving out of place. Make sure the spring side is towards the motor.

 

[broncnaz]

Sounds like you have another issue like a blown head gasket or something. It takes my bronco about 2 miles before the temp will get up to normal. thats with outside temps in the 30's. From a dead cold engine you shouldnt overheat in a one mile span as the temp shouldnt weven get hot enough for the t stat to open. So I thik you have another issue.
Is the water actually hot at this time when its boiling over? Whats the gauge say?

 

[oznerol_68]

So would have I caused the gasket to blow then, was running scary nice before the t-stat change, even with the overflow hose with the screw and clamp on it. kinda sounds like pump is dry or something, think its from the water pump or could be from the antifreeze getting all over the place maybe the alternator, dont know, stressed out HELP!!

 

[73azbronco]

if it's that cold I wager you have ice in the block/radiator blocking flow...

 

[Steve83]

I'd use a torch to warm up the radiator & make sure it's not frozen. Warm up the engine, then drain everything and install a 180/190 t-stat with the copper side toward the engine, and make sure it stays in-place during installation. Refill with 50/50 antifreeze & distilled water (don't buy ready-mix OR long-life). Disconnect the upper heater hose during filling to vent any air.

If it still blows out coolant, the water pump impeller may be slipping on the shaft, or it might have been damaged by freezing or rust. Low coolant & overheating won't hurt the WP.

 

[Quick & Dirty]

If it's overheating that quick in cold temps, I'd say your radiator or hoses are frozen shut.

Or, it's not actually overheating, the radiator is overfilled and as it warms up the expansion is overflowing. That's normal if you don't have an overflow tank and top off the radiator.

Is it boiling, steaming hot? Or just pushing coolant out?