So my daughter and I took a red eye flight several hundred miles away to buy a 2007 MX5 GT and took it on a road trip home. It only has about 48000 miles on it. We had a blast. However, about 4 hours into the trip, the check engine light came one. The original owner had installed a scan gauge- code was P0126 - which is coolant temperature related. I cleared the code at least a half a dozen times. I now have the scan gauge set on water temp - it was about 159 degrees Fahrenheit. During the trip the cluster gauge for water temp was near the middle, but slightly over towards the cool side.

I am probably going to take it somewhere for service and get the thermostat replaced. In the meantime, I'm going to keep an eye on water temp using scanguage. Does anyone know the normal water temp range for my car?

 

Highway cruising should be about 200 to 210 degrees fahrenheit.

 

ok, it threw the error twice today. Both times the water temp was between 155° and 160°

anyone have an opinion weather it's the actual thermostat or a sensor? I thought I read somewhere that there is a sensor that can also go bad.

 

Remove the thermostat, flush the cooling system, fit a brand new genuine thermostat, fill cooling system with FL22 coolant, bleed the system.

Clear the code, drive it & see what happens.