Hi

My car runs at about 3/4 and sometimes a little higher on the temp gauge.
i had just replaced the stock radiator with a brand new koyo aluminum radiator and an 16" electric fan rated at 2400cfm. The car runs strong and has great power still and i cant seem to find a leak by the water pump or anywhere else for that matter. everything looks good to me. I have just replaced the thermostat out and there wasnt even a thermostat in there before. Is it possible that it could just be a bad reading on the Temp gauge? After replacing these parts thinking it would do the trick. Im clueless to what it could be. I havent yet changed the hoses cause they seem good still. Also i start the car up and it does the 3k rpm thing, not much of a problem, i stick it in first gear and it goes away but the idle goes from 1k - 1.5k back and forth reving still and continues doing this. Sometimes i get a regular 750 idle out of it but then sometimes it does that reving thing. If you have any idea on what to check next for me please feel free to post.

Thank you for your help in advance. yes i did search and i read through the AronCakes Cooling problems and tryed to trouble shoot but im still having the same 3/4+ Overheating issue and the idle problem

thanks again,
Mike

 

Check your idle screw on the UIM. I may be extended too far and bumping up your idle

Check your waterpump/alternator belt tensions. If you've removed the airpump then you WILL need to get the dual pulley. My car would run extremely hot when I removed the airpump before I got the dual pulley. Then months later it started to raise again. The belts had gotten glossy and were no longer gripping like they use to.

Also on a S4 stock guage 3/4 is anywhere between 205-215`F be careful. Your close to blown engine territory there. Pay $60 and get an autometer temp guage. You'll be happy you did.

 

Well i still have all stock emissions on and airpump is still there. Thats my next thing to get is a aftermarket temp gauge. Anything else it might be? btw thanks for the relpy.

 

Did you use a Mazda thermostat, or some cheapie?

 

just a cheapie but i didnt think it would make that much of a difference when changing it out. unless it really does? at first there was no thermostat and it was running 3/4. so im clueless on what else to do.

 

I dont trust the stock gauges to much. I second the notion to get an autometer mechanical gauge.

 

I just solved my second RX-7 "hunting idle" problem. The first time, the thermo wax thingy that controls the fast idle cam had failed, keeping it on fast idle. The second time, the throttle cable was too tight.

In both cases, the root cause is clear - the throttle plates were open more than they should be (they should be closed). When you set your TPS in this condition, it confuses the heck out of the car since it's expecting the engine speed to be controlled by the BAC valve. So, check those two things I mentioned, plus the throttle cable for the cruise control.

 

Be sure to use the OEM thermostat. I know it's more expensive but you might toast the engine with a cheapie. I've had non-oem units fail. As far as it doing this 3/4 before, was it before you put in the e-fan? Also if you have a S4 than the gauge should be about 1/3 up on the scale. These S4 temp gauges are reasonably accurate. The S5 should be at half-way If the S5 gauge goes past that then shut the car down right away. The S5 gauges have 3 settings, cold, normal and overheat.

 

its an S4 and before and after i installed the E-Fan its been at 3/4 temp. so im not sure what else the problem could be. ill check the above on idling also .thanks

 

Thermostat could be it. My failed tstat symptoms were really high temps during highwau driving and normal ones on regular roads slower speeds.

 

well after driving out tonight i blew the drivers side heater hose.. im guessing that was the problem of cooling. so ill change that tomorrow and see how that works out.

 

That might've been it. Just remove the heater hose and cap it off (unless you really use the heating system).