i have a 87 rx-7 that overheats at 55-65 mph area i am new to these but from what ive read so far its probally clogged radiator or a missing underbelly pan? should i start by replacing the radiator? or do you guys think its something else it already had a thermostat replaced but i dont know what kind

 

Take it to a radiator shop and get them to flush it out. It's not dear and works well if its full of gunk

 

should i just buy a new one? would that be better if so is silla a good brand its like 150 sumthin for one if that doesnt work what else could it be?

 

Well the pressure clean should cost you like $30 im running a modified FC and the radiator is still fine. If you feel like blowing cash sure go out and buy a new one. But I would be getting it cleaned first. And did you put a genuine thermostat in, aftermarket ones have been known to cause problems

 

you never said How much the car is overheating on the gauge?..S4 or S5?..and is IT missing the belly Pan or not?.and also does the Rad have the Rad shroud on it?

 

Is the car for sure overheating? Is the coolant bubbling into the overflow tank and spraying out onto the ground, or is your temperature gauge just going up higher than normal? The stock gauge can be unreliable.

Make sure you have the stock fan shroud on the radiator. The underpan is also a very good idea, though driving with mine off for a while didn't cause my car to overheat. You also said the thermostat was recently replaced. Make sure it was a new OEM Mazda thermostat. Make sure your waterpump spins freely and that the belt isn't slipping. If this doesn't help, take the radiator out of the car (4 bolts, real simple) Stick a garden hose in on full blast. That's how I unplugged a big clog in the radiator of my TII when I first picked it up.

If none of this works, I will come give you $250 for the car

 

i forgot to say that its the non turbo one and another question i had is is it possible to put a turbo on this motor? i dont really want to buy a whole motor tranny etc....

 

Yea it's possible but less cost effective than if you were to do a drivetrain swap. If it turns out that you have a blown coolant seal you're gonna have to look into a new motor anyway .

 

Either get a new rad. Or simply, let your car get to operating temp. then drain the rad then refill it, (dont keep putting anti-freeze in it, just use water untill your done cleaning it, this can take a few days if needed. Keep doing this process untill its cleaner.

 

look into getting a new thermostat too

Also, are your fans coming on whenver your cars reachs that temp?