Gotta be the classic air bubble, right?

[zachmac]

I had a good running car that would hold temp fine and cycle between the 9 and 0 on the gauge as the fan cycled. I pulled the radiator to install new aluminium crank and water pump pulleys from Mr. Miller (nice stuff!) and as I was putting it back also installed a new electric fan.

Buttoned it all up and put all the fluid back that came out by burping the air by squeezing the upper hoses BUT I did NOT do the recommended fill with the upper hose to thermostat hose upright. Sure enough now the car wants to overheat. The water pump is pumping and the thermostat is opening, but the car won't cool. The fan temp. switch wont kick it on (more evidence engine heat is not getting to the radiator) but if I bypass it the fan runs. Even in this mode the engine temp creeps continuously up. Got to be an air bubble, right?

I ran out of daylight and don't want to dump coolant on the garage floor so I'll have to wait until I get home from work tomorrow to pull it into the drive and try a proper high point fill.

The wierd part is all the fluid that was in it before when it worked went back in? There is the chance that I just now filled the heater core as I also refurbished it and I am not sure I had run it before with the valve open? It is definitely seeing flow as the inlet and outlet pipes are piping hot!

[narfire]

Yeup,sounds like an air bubble. Likely the fans not comming on cause no hot water is getting to the temp switch at the lower driver side of the rad.(feel the hose) Members are plumbing a "T" where the hose is comming from the block (highes point)to the heater pipe at the firewall. Some have drilled a small hole inside the thermostat(see IAP tech bulleten regarding rads).
You'll get sorted in no time.

[zachmac]

Yeup,sounds like an air bubble. Likely the fans not comming on cause no hot water is getting to the temp switch at the lower driver side of the rad.(feel the hose) Members are plumbing a "T" where the hose is comming from the block (highes point)to the heater pipe at the firewall. Some have drilled a small hole inside the thermostat(see IAP tech bulleten regarding rads).
You'll get sorted in no time.

Yeah, my thermostat has the bypass hole. Like I said, I know better, just got lazy. I'll pull and rotate the T tothermostat hose and do a high point fill tomorrow. Hopefully that will be that!

BTW, does anyong know of a lower temp. radiator fan switch that will screw into the stock location?

[mbouse]

try this.... put a flush T-fitting in the hose between the head and the heater core. make your final fill here, patiently replacing all the air bubbles with coolant.

Bernie's car, not mine.

[So Cal Mark]

sounds like you may have the thermostat installed incorrectly

[zachmac]

try this.... put a flush T-fitting in the hose between the head and the heater core. make your final fill here, patiently replacing all the air bubbles with coolant.

Bernie's car, not mine.

Only problem is I already have a T there to accomodate the throttle body heater plate (look at your 80 FI car connections)and there ain't much room to insert a second T.

BTW, I have the hose coming up form the coolant pipe under the exhaust going into the heater core left most connect (as viewed in you picture, facing from front) and the "return" from the heater core going over to the block. Shouldn't make any difference since flow direction through the heater core doesn't change anything outside of it's loop, correct?

I may add a flush T there anyway, just pretty crowded with the other T already there.

[zachmac]

Mark,

No, thermostat wasn't removed since it worked fine.

Greata news! Luigi hes a all a better! He musta eat a something bad yesterday cause he all hot a headed and won't a cool off. Today I say Luigi, whya you all hot headed and I a rub his belly (and vent his coolant system properly) ana he let out a bigga burp. Now hes a all better, cool headed and ready fora me to screw him upa some more.

BTW, the boys named him Luigi since he's green and they tell me the red one is Mario.

[So Cal Mark]

the air bubble gets stuck at the thermostat, if the stat opens you have circulation through the radiator and the fan should work.