Thermostat Air Hole

[natenkiki2004]

I'm finishing up putting the top of my engine back together (lower intake coolant leak & replaced rockers & pushrods) and whipped out the new thermostat I bought. It's a Stant SuperStat 45369 195*. Compared it to the one that was installed and noticed that there was no air bleed hole on my new one. Is this a problem? I've already got the new one installed but will finish assembling everything tomorrow to fire it up.


*EDIT*
The one I ordered is a "premium" one from Rock Auto. According to Stant's website, it's ok?

WHAT DOES A JIGGLE PIN DO?
It helps bleed the cooling system of trapped air by allowing air to pass into the radiator and released from the system.

MY THERMOSTAT HAS A JIGGLE PIN BUT THE STANT THERMOSTAT DOESN'T. WILL A STANT THERMOSTAT STILL WORK?
Yes. Many thermostats have a “jiggle pin” that allows trapped air in the cooling system to pass through the thermostat and be released from the system. Some Stant thermostat do not use have a jiggle pin. These thermostats will have a "bleed notch” or other method of removing air from the system.

 

[xplorernewb]

id replace it with one that has a weep hole..

 

[swshawaii]

Many different opinions on different forums. Your call. GL

http://www.explorerforum.com/forums/showthread.php?t=162165
http://www.explorerforum.com/forums/showthread.php?t=71038

 

[2stroke]

It's only purpose is to make it easier to bleed the cooling system. You can absolutely use it as it is. If it was me, I would take it out, and drill a hole.

 

[Anime]

Like you found out, the Superstats have a "bleed notch" or "v-notch" instead of a round hole with a jiggle pin.

The v-notch provides a small initial flow. As the engine heats up, the v-notch gradually opens wider, metering coolant into the system until the desired engine temperature is reached.

http://www.stant.com/index.php/english/products/consumer-products/thermostats/superstat-thermostat/


Seems to work well for the 4.0L OHV. I've been using 195 degree Superstats instead of the OE Motorcrafts and have been very pleased.

 

[the_don]

Last time i did mine i just dill a 1/8" hole next to the gasket.

 

[natenkiki2004]

I did think of drilling a hole but I didn't for 2 reasons; I didn't want to mess with the Stant design and there's temperatures during the winter where the engine needs to heat up as much as possible as soon as possible and adding a hole may slow that down.

Anime, like you said, I did see something about a notch but I inspected the thermostat before putting it in and couldn't find anything obvious as far as orientation.

Guess I'll find out tomorrow when I add coolant and pre-burp by squeezing the rad hoses. I know what the old one was like (also a Stant but with a jiggle pin) so I have a good chance for comparison.

I will say that my old thermostat had issues with warming up and cooling too much then closing and opening a couple of times. I always thought it was the bigger radiator but maybe the new thermostat will help.