[Vincentnova]

hello
i have a 350 CHEVY ENGINE
i did a replacment manifold and carb
i discovered then the engine didn't have a thermosta ? i was wondering before why the engine never went up in temperature...well now i know
( it's a projet car never ,drove yet with it )
i put in place a new thermostat ( spring domn to manifold)

now the engine want to overheat....!!!!
no coolant in engine oil , i checked
my coolant in radiator is very clean ( the coolant is 50 50 green )
i did a compression test at the radiator cap , everything ok
no leak ,nothing

i turn the engine on ,with the radiator cap off
after a minutes the water want split out
but i didn't see the water going up and down

the water pump is bad ?
or the radiator is clogged ?

it's a 1971 chevelle
thanks

 

[boatbob2]

?????????

I think your thermostat is NOT opening,take it out,put in in a pan of water on the stove,heat it,look for it to open...if it doesnt open,buy another one.

 

[Vincentnova]

is it possible ? its brand new?

 

[S10 Racer]

is it possible ? its brand new?

Just because it's new does'nt mean its good. Check it like boatbob2 said.
I have never seen a water pump "clogged" but I guess it's possible but usually when they go bad they just leak or have a bad bearing. It sounds like you still have air in the cooling system that needs purged out. If there is air in it, the thermostat may not be getting hot water to it to open it.

 

[Vincentnova]

AHH yes i see
could you tell me how to purge the system ?
im going to try that first
thanks

 

[S10 Racer]

AHH yes i see
could you tell me how to purge the system ?
im going to try that first
thanks

The best way is to drill an 1/8" hole in the thermostat. Drill it so that the hole will not be covered back up with the gasket.
Usually purging is not required for older engines where the radiator cap is the highest point in the cooling system but it won't hurt to try. Make sure you test that thermostat first.

 

[Localboy808]

AHH yes i see
could you tell me how to purge the system ?
im going to try that first
thanks

Vincent, leave the radiator cap off. Start the engine. Let it run until it starts burping water and air out of the radiator. Feel the hose coming into the radiator. It will be cold while the thermostat is closed. When you feel it get warm you will know your thermostat opened. It should start burping any air out. When you think it's all out make sure it's topped off and close it up. Drill that hole like the others have mentioned. Good luck.

Did you try flushing the radiator out at all?

 

[Vincentnova]

i tested the thermostat , it's working
i drilled an hole
put it back
after a while i started the engine and still want to overheat.....

i start the engine again without the cap at the radiator
the coolant was a little down compare to last time
i saw it going up a little ( slowly) but not burping any air or water

 

[Richiehd]

Sounds like water is not ciculating. Correct rotation water pump? Hose collapsing? Check radiator and make sure it is EVENLY hot throughout, could have some clogged cores. Is fan pulling air through radiator? Clutch fan not hooked up?