Who sells a good low temp thermostat? Az heat is beating me and throwing in my koyorad and want a low temp. Everything I see is oe type. Help?

 

A low temp thermo won't solve your issue and may make it worst, You need to chase down why your car is overheating / cooking your thermo.

 

Hello from a fellow AZ resident. Your KoyoRad is enough; being all aluminum, it conducts far more heat away from the engine than the OEM brass rad, and I don't even worry about my engine temps anymore, going on 6 years. The Thermostat is set for the engine to come up to temp to operate efficiently at a range of around 190F to 210F, landing somewhere in the middle. If you're sitting at idle with the A/C running full blast, it's going to spike a bit toward the upper temp, but you may not even see this on your gauge. As long as it's not overheating now, your new Radiator should be fine with the existing (*known good) Thermostat. I wouldn't replace it unless it was overheating, and even then, I'd test it in a pot of boiling water on the stove before throwing it away.

The KoyoRad is maybe the best insurance you can install for your car if you drive in desert heat. I was in the habit of boiling out the OEM and rodding it out every 5-6 years. Now, I don't even think about it anymore.

Pro-Tip: with aluminum radiators in particular, you should take time to check for conductivity between ground and coolant as measured through a probe down the radiator neck. If you're reading any voltage potential, check your engine grounds and make sure they're solid, or you risk rapid deterioration of that expensive new Radiator.

 

100% on the known thermostat , Mazda OEM is almost always solid but anything else has a high out if box failure rate . Test it as longduck said , also if you do get a new rad always pressure test it before installation .