Random overheating and dipped idle.
 

As the title states it randomly overheats for about 15 seconds while the idle dips and it hesitates a bit. The idle dips then goes back up and repeat. Gotten this twice lately and only happens once per day when I first take it out. Whats got my confused is I just replaced the thermostat and my coolant is topped up in the radiator and in the tank. This is a first and quite frankly it's pissin me off. Anyone got any insight to this bullshit?

cleanse the radiator...of its sins.

You really think that is what's causing it? I'd be pretty happy if that's all it was.

dude, just pick up the Prestone cooling system cleaner for $8 or whatever it costs and follow the directions! Worked like a dream on an 87 Blazer I fixed this summer.

I shook half a quarry of minerals out of my radiator from the green car when I swapped it for the new one.

If the thermostat works, there are no leaks, and the waterpump works, then you have an obstruction somewhere. Distilled water only! Its pretty much the only miata.net-ism I support.

Nuff said. I'll let you guys know if anything substantial falls out.

Hey, if its an old rad, and you've run groundwater through it, you might have an obstruction.

Complete bullshit. Flushed it and it's still overheating. What's next?