Hey, im 17 years old, and just bought my first Rx-7. Its a 87 Se 5 speed. It's all stock right now, and I love this car and can't believe I've finally got one after a year of working my *** off at less than $6hr. I live in rural nowheresvillie tennessee, and most of my driving is on open roads, but I've noticed after the car gets warmed up, then it idles for about 5 mins. like in traffic or repeated red lights, it will overheat. It really suprised me the first time 'cause the stock temp gague was only about 5/8 of the way up on the gague. I am somewhat mechanically inclined but I've never had cooling issues with any of my other cars. AND no it isn't leaking fluid, and it is filled. Any help would be great.

 

check your thermostat, it is located right by the cap where you fill your coolant, you will have to take the coolant neck off, (i think its 2 12mm bolts) and in there u should see a small little round thing(the thermostat), pull that out and get a new one (preferably a mazda one made for your car). Then after that u should probably flush your coolant anyways.

 

damn, i would bug out if my guage went past a 1/4. overheating on rotaries is BAD.

 

it boils down to 4 things. radiator , water pump , thermostat , heater core .
you might try buying one of those prestone engine flushing kits . i know on my car i had a overheating problem, so i did the whole system new water pump, thermostat ,
and went to the junkyard and picked up a used radiator. at the yard i looked for a rather dirty radiator (for a 5 speed) when dirty you can tell if there were leaks, with straight fins and pulled it, paid $45.00 dollors got it home and cleaned it up, flushed it out. the passage ways on these radiators are pretty small and i guess clog up easy. bought a 180 degree thermostat and water pump. installed all pieces. before installing the thermostat (install the thermostat last ) with the radiator and water pump and all the lower hoses in place, place the garden hose in the thermostat housing and fill the engine with as much water as it can take then install the thermostat and the filler neck then top off with water. and fill the overflow bottle about 3/4 with water also. start the engine and check for any leaks. my temp guage doesn't even reach the 1/4 mark now. good luck

 

Thanks, but whats the difference between the Mazda therm. over the one i can pick up at auto zone?

 

Reliability. On the old boinger engines that I had, They would not open up after a while and blow head gaskets. Go and spend the extra $$ and get a OEM one. While you are there, pick yourself up a couple of oil filters. They are higher quality then the regular parts store ones too.

 

Just so ypu know, there's a few rotorheads here in seymour that will be glad to help with advise, also the 'guru' of all that is rotary, Kevin Landers, lives in morristown. So, worst case, he can defintely help ya out.
And yes, you want the mazda thermostat, no question.

 

For Future Reference..... when your stock gauge is at 1/4.. you engine is at about 190 degrees... when your stock gauge is at about half, its about 220 degrees... (this can vary depending on the oddball sending units... they are junk)

Does the car have an E-Fan in it???????????? Seems funny that its OK on the highway not at idle...

ALSO... you may want to check between the radiator and the A/C heat exchanger in front of the rad to see if there is 16 years of furbunnies cloggin up the air flow like there was in mine when i got it!!!!!

 

Hey, I was under the impression that on s4's the gauge can only got 1/4, but on s5's the gauge actually stops halfway, am I right??

 

Sounds like bad o-rings. Thats how mine was. Pull the thermostat out then put the housing back on(no thermostat) and start the car. If the coolant is constantly bubbling(air) or shooting out then you need a rebuild.