1997 4Runner 3.4L Auto trans

I just finished up a swap of a cracked radiator...replaced all hoses and thermostat as well. The thermostat I got at Napa fit but did not look the same. No jiggle valve at the top and slightly different mechanism...but I figured a thermostat is a thermostat. Once I ran it, it became apparent that the thermostat is not working. No heat blowing from the vents and the motor over heated fairly quickly and no coolant was drawn from the reservoir. Did I put a thermostat in for the wrong sort of motor? Do I have to replace the original with an identical (jiggle valve etc) one? Or did Napa sell me a bum thermostat? Thanks for the help.
Rich

 

Could be all of the things you listed !!

Thermostats I go with Toyota the after market ones have really gone down hill at least the ones I see

 

You did fill the rad?

 

...and OEM thermostats aren't as expensive.

 

Well now I may be a bit of an idiot. I did not fill the radiator but did fill the coolant reservoir...figured the radiator drew from that. Should I also fill the radiator first? Obviously I'm not an experienced cooling system mechanic. I took the thermostat back out and boiled it and it functioned as advertised. I assume the jiggle valve that was on the original is to allow air out. How big of a deal would it be if this doesn't have that? Thanks for the help all of you - much appreciated.
Rich

 

I'd fill the rad and see what happens...

Filling the rad will probably help more than the jiggle valve.

 

Thanks Marc - I'm going out for another crack at it.
Rich

 

Park on an incline also and make sure to "burp" the air out of the cooling system. The yota thermo is not that expensive and it lasts a long time. If you replace the thermo again, jiggle valve at 6 o'clock.

 

Thanks gents. I did park it on an incline (facing up hill) and by burping do you mean leaving the cap off as I add coolant to allow the air to escape? I just took it for a test spin and she's running cool! I think I'm a dumb dumb for not realizing that 1/2 gallon of coolant in the reservoir was not nearly enough! I really appreciate all the help.
Rich

 

Glad it's working better.