28 replies to this topic

[Mark]

Randy,

 

It has been several years since I've had a 94/95 in the shop but I remember being surprised when the fan on my 95 didn't come on at 207 as expected. I was told by someone, I forget who, that the 94/95 fans came on at a higher temp than the 90-93. Emmisions related? My car behaved exactly as yours FWIW. 

[Randy Wolfgram]

Randy,

 

It has been several years since I've had a 94/95 in the shop but I remember being surprised when the fan on my 95 didn't come on at 207 as expected. I was told by someone, I forget who, that the 94/95 fans came on at a higher temp than the 90-93. Emmisions related? My car behaved exactly as yours FWIW. 

 

Thanks, Mark.  By behaved the same, do you also mean the on-track temps (running in the 210 - 220 range in clean air)?

[Mark]

By 'same' I meant the fan temp. On track the car ran the same temps as every other Miata around here AFAIK. In the summer it was difficult to keep temps below 205 when racing (draft, socal high desert temps). This is with a big Springfield radiator. If you are seeing high temps now in cooler weather something else is going on and would definetely be something to look into. I have seen similar issues in cars with the heater core hoses not sealing well or radiator caps that don't hold pressure and causing small pressure leaks. Have you pressure tested the cooling system? Are you running the car with the undertray on? The undertray does help cooling.

[Randy Wolfgram]

Okay, that's what I thought you meant, but thanks for clarifying.  I haven't pressure tested so I guess that will be my next step.

[Randy Wolfgram]

Okay, still chasing this.  I swapped out the CSF for a brand new Springfield Dyno, but still seeing the same results.  Question.. is my "test" even valid?  I'm just letting the car get warmed up by idling in my driveway, not even running on the street and it gets up to 217, fan kicks on, cools down to 197 and then the fan turns off (water temp drops a few more degrees down to 195), then climbs back up.  Admittedly, I'm in major learning mode, but without any air moving across the radiator, what is it that is supposed to hold the water temp at a stable temp?  I'm sure I'm missing some concepts here, so bear with me.

[James York]

Okay, still chasing this.  I swapped out the CSF for a brand new Springfield Dyno, but still seeing the same results.  Question.. is my "test" even valid?  I'm just letting the car get warmed up by idling in my driveway, not even running on the street and it gets up to 217, fan kicks on, cools down to 197 and then the fan turns off (water temp drops a few more degrees down to 195), then climbs back up.  Admittedly, I'm in major learning mode, but without any air moving across the radiator, what is it that is supposed to hold the water temp at a stable temp?  I'm sure I'm missing some concepts here, so bear with me.

Sitting still with no air across the radiator, other than when the fan kicks on, is only basically testing when it switches on/off.  (217 F for on seems high to me, but I am not very familiar with the 94/95.)

 

You have to be moving for the car to stabilize at a constant temperature...  around your themostat setting if you are running one.

[Randy Wolfgram]

Sitting still with no air across the radiator, other than when the fan kicks on, is only basically testing when it switches on/off.  (217 F for on seems high to me, but I am not very familiar with the 94/95.)

 

You have to be moving for the car to stabilize at a constant temperature...  around your themostat setting if you are running one.

Thanks, James, that makes sense.  I'll just have to see how it behaves next time at the track.

[Duane Polsley]

You should add this as well if you haven't already.

 

http://www.redlineoi...ts.aspx?pcid=10

[Randy Wolfgram]

Ya, thanks, Dewey.  I'm currently running that.