Coolant Boiling out of overflow

[19COBRA93]

I did all the work myself. New motor. Same coolant system. I've changed the thermostat and checked the water pump so far.

What motor? Same aluminum block?

 

[W3bb3r04]

Yup same block. Just rebuilt the bottom end and freshened up some different heads

 

[W3bb3r04]

I'm starting to think there's a blockage somewhere but it doesn't make sense that I can blow coolant through the system

 

[W3bb3r04]

Does anyone else have any other ideas? Im going to try the vaccuum approach if no other ideas pop up.

 

[BruceH]

Have you run it up to temp with the cap off?

 

[W3bb3r04]

Yeah I've tried it on and off as well. Took the upper radiator hose off on the radiator side and while the thermostat was open, there was no coolant moving unless I blew into the overflow or heater hose. I disconnected all the hoses as well and flushed them with water earlier today but it didn't seem to do anything.

 

[deebo05]

have you tried filling it without the t-stat and see if it will move water then.

it sounds like you have air trapped in there

you could also remove the crossover and fill each side of the block with coolant.

 

[W3bb3r04]

have you tried filling it without the t-stat and see if it will move water then.

it sounds like you have air trapped in there

you could also remove the crossover and fill each side of the block with coolant.

No I have not. I have to lift the intake to get the elbow off so I haven't tried that yet. I am trying to think of other ways to bleed the system. Its got to have a big ass air bubble in it if that's what it is.

 

[W3bb3r04]

I'm stumped anyone have any other methods of testing?

 

[michael.konor]

Well there are only two things that stop flow. The first is your water pump, but since it was working before and you didn't mention damaging it on installation, we can rule it out. Second is blockage.

Blockage could be anything from installation debris **anywhere** in the engine, including in the block and radiator, or thermostat. And of course a bubble you can't free up.

Just had a thought. Did you by chance change water pump and install one that goes the other direction. Don't ask why I know that....

 

[19COBRA93]

What head gaskets did you go with?

 

[W3bb3r04]

I think I may have gotten it figured out. I put a funnel on the overflow, filled it to the top and the pushed the lower radiator hose. Lots of air has come out. Running, it pushes water out of the heater hose lines now. I'm going to get it up to operating temp and see how she does.

 

[W3bb3r04]

I have heat now too. I guess I got it. Thanks guys!

 

[AutoXRacer]

I am surprised people continue to service their cooling system without a vacuum fill...

These cars are not designed as the old school motors where you just fill it and let her warm up and add till full. You need to vacuum fill the late model cooling systems.

 

[19COBRA93]

I've never had an issue filling a 3V the "old school" way.

 

[05gtowner]

Me either. I just did a 100k mile cooling system overhaul and replaced the radiator, water pump, thermostat and the hoses. Filled it up the old school way and haven't had an issue in the 20k miles since. Not to mention I drive up to the high desert daily for work which includes about 20 miles of driving up hill with the ac on.

 

[JeremyH]

Good to hear RJ!

 

[BruceH]

I've never had an issue filling a 3V the "old school" way.

Me either. I just did a 100k mile cooling system overhaul and replaced the radiator, water pump, thermostat and the hoses. Filled it up the old school way and haven't had an issue in the 20k miles since. Not to mention I drive up to the high desert daily for work which includes about 20 miles of driving up hill with the ac on.

Me either. I try not to fix things that aren't broken, lol.

 

[lethe]

I've never had an issue filling a 3V the "old school" way.

Same here.

 

[Bobby]

Good to hear rj