here's what i've observed, the temp gauge inthe car goes up to a little above 1/2, it's a '86 gxl so it's suppsoed ot sit around 1/4 as i understnad it... if i'm sitting at stop lights it cools off to a about 1/3 but if i'm moving it goes up to little above one 1/2... it doesn't matter the ambient temperautre or the how fast i'm going.. it does depdns on engine speed some.. if i'm cruising at 3k rpm it'll be little above half(like on the free way) if i'm at 2k it'll get a little below half.. but if i'm driving at 3k going around 45 mph it goes to a little above 1/2.

that's just what i've notice from the stock temp gague, which i've read is not all that accurate, so after goign out ot lunch todya and getting back to work with the temp gauge abotu 1/2 i measured the temps fo teh thermostat housing, the top of the radiator and the bottom of the radiator using a themrocouple and a FLuke meter from work.
I know ths isn't the most accurate way to measure the water temp but i thought it would atleast giv eme an idea of where i was. Also i didn't think that the temp measurment on the thermostat housing woudl be pretty accurate since aluminum is a decent conductor of heat. Here's what i found:

Thermostat: ~193 F
Radiator Top: ~163 F
Radiator Bottom: ~125 F

so i know i am running warm now, but I'm not sure what to replace next, i replaced the thermostat(mazda oem) last weekend, that didn't change anything... I will try flushing, but i was told from the person i bought it from that it was flushed 3 weeks before i picked it up... i picked it up about 1.5 months ago.. but flushig it again can't hurt... but if that doesn't help enough what cooling system component to these symptoms point to?

 

Yeah, I would say that flushing the radiator and adding the right mixture of coolant/distilled water should be the next steps. I'm in hot, hot Texas so I used a 30% coolant and 70% distilled water solution. I did just that this past weekend and it made a dramatic difference. Also, make sure the belts are the proper tension. If they're loose, they won't interact with the fan pulley properly. I also got the garden hose nozzle and sprayed the radiator clean from the back side. A lot of crap like leaves and feathers came out. I'm sure that was diminishing the cooling abilities of the radiator. If all that doesn't make a difference, the next step is a water pump inspection.

 

thanks! i'll do that soon

also i was researching more and realized i need to find a front shroud or duct or whatever it's called since mine is missing

 

Oh yeah, I forgot to mention that. Make sure your fan shroud is there and also the plastic tray under the engine, in front of the sub-frame. They're both important in guiding the flow of the cooling air.

 

http://www.aaroncake.net/rx-7/cooling.htm

 

yeha i have the fan shroud but i'm missing the front underbelly tray... gettign one soon though... I'll post the result after a flush and clenaing and the front tray...

and thanks for the link, i actually found that right after i posted yesterday and that's where i found out about the front tray