Cold lower hose question - thermostat bubbles?

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BurbankJalopy

Cold lower hose question - thermostat bubbles?

Post by BurbankJalopy »

Hi all
I put in a new thermostat and now I've got a cold lower hose, and the engine gets too hot after several miles and pushes it out into the overflow. The upper hoses seem like there's quite a bit of pressure, too. Can an air bubble in the thermostat (stuck in the lower hose section) cause the thermostat to not open? I didn't drill a purge hole for air bubbles/bleeding. Theoretically it seems like it should still open the lower hose because the wax is in the upper portion of the thermostat, which gets hot enough to open the lower hose outlet and let the air bubbles out. Should I just take it apart and drill the hole to see if that fixes it? I put in the new thermo because it; took too long to warm up, cooled down while coasting, overheated while idling. Thanks in advance.
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kilrwail
Posts: 1100
Joined: Wed Mar 04, 2009 6:49 am
Your car is a: 1978 Fiat 124 Sport Spider
Location: Perth, Ontario

Re: Cold lower hose question - thermostat bubbles?

Post by kilrwail »

Sounds like you may have installed the thermostat incorrectly. This thread covers the subject thoroughly:

http://www.fiatspider.com/f08/viewtopic.php?f=9&t=8057
_____________________________________________________________
Peter Brownhill

1978 Fiat 124 Sport Spider - original owner
1977 Porsche 911S - track car
2022 Ram 4 x 4 - hauler
PCA National Instructor and Motorsport Safety Foundation Level 2 Instructor
BurbankJalopy

Re: Cold lower hose question - thermostat bubbles?

Post by BurbankJalopy »

Thanks for the response. I do have the 'blocked' outlet at the lower radiator hose, so I know that it is in there correctly.
deacon

Re: Cold lower hose question - thermostat bubbles?

Post by deacon »

I am fighting the same thing and have the other thread going. I am going to give another good shot at burping the cooling system before getting more drastic. Hopefully we will both know soon.
So Cal Mark

Re: Cold lower hose question - thermostat bubbles?

Post by So Cal Mark »

on your FI car, do the final fill through the plenum heater hose, that will get all of the air out. Make sure the heater valve is open when you fill it
BurbankJalopy

Re: Cold lower hose question - thermostat bubbles?

Post by BurbankJalopy »

Thanks Mark. That's how I've been doing it but I was a little sloppy last time. I'll try it again, along with drilling a hole in the thermostat - maybe. Do you drill the hole in the thermostat on your cars? Oh yeah, when I squeeze the hoses I could hear 'aerated swishing' around in the engine/hoses/tubes so it definately has some air.
So Cal Mark

Re: Cold lower hose question - thermostat bubbles?

Post by So Cal Mark »

yes, I drill a tiny hole in all thermostats
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