At what point on the temperature gauge is it worth starting to worry about overheating?



Mine runs about 1/3 up during city driving, and light highway driving, but as it's getting warmer out (today is close to 90) it spends it's time about halfway up on the highway. As I understand it, this is getting uncomfortably close to meltdown, so I've been opening the heater up a bit to drop the temperatures (I run with the windows & sunroof open, so I don't even notice).



Am I justified in worrying about it being halfway up, or should I look at replacing the thermostat/radiator at some point in the near future?



Also, I removed my (seized) air pump. I blocked off the hole on the air filter. Do I need to worry about the opening on the ACV? Right now it's open.



-=Russ=-

Mine has always been halfway up. Is that bad? I thought it was normal.

I wouldn't worry about 1/2 way up... mine for whatever reason never gets beyond 1/3 no matter how hard I drive it. I take pretty good care of the cooling system, flush once a year and run 80% water, 20% coolant... I have the 1.3 bar Greddy rad cap which I think helps too.

Half way is fine, but I'd start worrying at near 2/3s...Mine runs 1/2 in 95 degree weather...

Half way is normal for an S5 (one that hasn't had the linear temp gauge mod), and one third is normal for an S4. Many S4's run at half way when it gets real hot. By real hot I mean 105+ in Southern California or 110+ in Phoenix and the AC on. S5's usually don't go above half way until imminent danger is upon them.

mine runs barley over cold with the koyo and a mazdaspeed rad. cap

h=235f on an s4 guage, they are accurate.

Wow. Would a Koyo radiator really do that much? My shortblock's S5 and everything else S4, and it runs at 1/3 consistently unless I'm cruisin' on the highway @ like 4,000+ since I have no 5th. At which point, it sometimes gets to half, and if I punch it, it will go a hair above half. If it does that, I glide in neutral, and it goes back down. If I were to just pull off the highway it would cool down immediately too.



I use like 80% coolant 20% water.

you should try to run 80% water 20% coolant it might help you out a little

remember though, if you aren't running your engine cooler than it should it won't run at it's potential. meaning efficentcy as well as power will be slightly compromised