ok i have an 88 mazda rx7 vert N/A and its always running hot when i drive it so i have to put the heater on to cool it down. i don't know why it does this and wanted to know if anyone can help? i think it might be my radiator but not sure and don't how to check... i do have radiator fluid and oil full so its not that...

oh and can anyone direct me the right way to changing my clutch out?

 

Define "running hot." On an S4, ~1/4 of the way up on the gauge is normal operating temp (~180F). But it is summer, so don't be surprised if it sits around 1/3 of the way in traffic / at idle.

Pick up a Haynes manual for details on removing the transmission to replace the clutch.

 

First place to start is with a radiator flush/cleaning, including removing the engine drain plug, a new Mazda thermostat, check the fan clutch, belt tension and for any play in the waterpump. If your radiator has a fill cap at the top of the tank, take it off and see if the cooling tubes have have any corrosion buildup. If so, it may be time to have the radiator boiled by a shop. Replacing the waterpump is good preventave insurance, check the fan shroud and make sure the under tray is still in place.

 

if blowing air thru that small heater core will make that much of a difference, then i'd say the radiator isn't flowing enough. take it out and have a shop clean it. have them flow test it before and after. let us know how it goes.

 

Do you have the plastic undertray in place?

 

i have an 87 my temp guage runs at half, and if i drive it long it will start to go a lil over

 

That......is not good...or normal...

 

i have a 91 running at a hair under half....

dosent move much from there after its warmed up

is that a bad thing also?

 

yeah ik, im gunna have to rebuild it soon, it also is a pain to start all the time

 

half gauge or little more is normal, especially if u live in areas that have high summer temps. if it's getting 3/4 or more it's time to worry. the average thermostat opens around 185 and guages usually have numbers on them but not every mark. u should be able to figure out how it's divided up and get a pretty good idea where normal should be.

 

I just got the car last week, but it usually stays at about half

 

awesome thank you!!

 

Thermostat temperature is 180*F. On an S4 this is 1/4 of the way up. 1/2 way is approx. 200*F and 3/4 is approx. 220*F. These values have all be measured by me.

On an S5 180*F is 1/2 way up instead. Beyond that, the S5 gauge stops being linear and starts sucking badly. A lot of S5 owners pick up an aftermarket temp gauge.

 

ok so from i read from everyone makes something really wrong with my car...
my temp, after it warmed up, reads almost at the top before the H...
so any ideas on what i need to do? get a new radiator? or what?

 

could be a number of things, not too often it's the radiator itself.

When was the last time you replaced the thermostat?
Do you have the plastic belly pan in place, goes directly under the radiator?

 

I have a load of cooling system troubleshooting on my website:
http://www.aaroncake.net/rx-7/cooling.htm

 

I had a similar problem. Turned out to be the fan clutch relay. Once that was replaced, no more problem! (my RX is and '85, so it may not apply)

 

i think its the original one on there... and yes i think i do have it

 

i have the same problem.. usually when im driving on the street, or in heavy traffic on the fwy its stays in the middle.. but when i start speeding up on the fwy going around from 60-80mph then it starts getting hot.. i had the radiator patched of all its holes, changed the thermostat housing.. and theyres always coolant to the top in my radiator.. it could be either of two things that i know.. i need to change the thermostat/or bleed out my radiator.. (flush) if its neither of those.. its the engine. i believe.. i also turn on the heater to cool it down.. and thats what makes me think its the thermostat.. check it out! it might be you have a small crack on the radiator too!