Ok, I have read the rx7 book on how to fix things and there is a part in it about over heating, and it says if its over heating check the drive belts to make sure they are tight....So I replaced all my belts and tightened them really well. I replaced my rad fluid with collant and water 70-30 mix. And when i drive my car over 4000rpm for like 2 mins its already getting past 3/4 on the temp. gauge. As long as i drive uner 3000rpm for the most part its fine. I bought a replacement thermostat....but Im not sure if thats what the problem is or not (cause the rad hose is hot, so the rad must being flowing through). I just want to get some opinions if anyone else knows whats happening.

-Daryl

 

Your fan clutchie thing might be broken, causing the fan not to spin fast enough. Also, 70-30 anitfreeze/water? You ought to be running more water than that. Unless it's real cold where you are. There is a guide on the antifreeze bottle. Try some redline water wetter too. The new thermostat might be crappy, everyone on here seems to be in favor of the mazda one over the stant one you buy at pep boys. I have a 180degree stant in mine and it works ok tho. I also have a huge fluidyne aluminum radiator though.

 

I've seen a bunch of overheated RX7s and the problem usually is with the Thermostat and sometimes the Rad being clogged. I would change your thermostat first, and if that doesn't help still, you might have to get a good used RAD put in.

 

Before you go for a new radiator, try that radiator flush stuff for $3 or whatever.. I've heard that it can do wonders. Its the kind that you pour in, let your motor run for 5 mins, then you drain everything and put fresh water/anti in. Do you have the plastic peieces that go in the front still in(both the ones over the radiator, and the skid plate thingy under)?


~Jesse

 

clutchie thing, thingy plate under

all these technical terms are confusing


J/K, jsut had to do it guys.

 

Ok, So the manual said to make sure all the drive belts were tight. And they WERE squeeling so I changed both of them, and they are really good and tight now.

I just got back from an 45 min drive, some hard some slow...And my temp gauge is up and down from the middle to the top(it'll go from the middle all the way to the top in like 30 seconds and then back again) So I parked my car at my place and there is noticeable "smoke" coming from under the hood...I open the hood and see that rad fluid or vapor is all over the place...and I can hear the engine boiling...SOMETHING is definitly wrong. I checked the hose and its hot so the coolant is getting around i think. Should I still try the rad unclog or is it something else?

Any more suggestions???

-Daryl

 

I have posted this before because others have had this problem.
My 87 was showing the same symptoms. What finally fixed it? Would you believe the water pump housing? The aluminum casting behind the pump was eroded by the turbulence of the high revving pump. The bypass valve seat under the thermostat had about a 4mm chamfer eroded away, and there was a 6mm hole eroded through the wall between the inlet and outlet side.

All this bypassing gives symptoms like a partially blocked radiator. I fabricated a repair with Bondo Marine Epoxy Putty Stick. It has held for a year now.

The other thing that sneaks up on you is the fan clutch. On the series 4 (86-88) version the fan pulls hard up to about 3500, and then maintains ~3500 as the engine revs higher. Mine was slipping at 2500. You can get the fan clutch to bite better by bending the bimetal strip outward. I ended up buying a new fan clutch.