Sounds like your thermostat is stuck open to me.
Does the NB Miata have two coolant temp sensors or one ?
One for the gauge and one for the ECU or just one that controls both ?
How much of a job is it replacing it, I have read that its in the back and is a pain to get to ?
Im asking only because my car always seems to run too cool, The gauge is always sitting at about a 1/4 unless the car idles for like 30 minutes with the AC on the car's gauge will never sit in the middle, All other cars ive driven get up to temperature in about a few miles of driving this is not the case with my NB miata i feel that it may just be the coolant temp sensor.
Car has an aftermarket all aluminum radiator.
Sounds like your thermostat is stuck open to me.
Mike Walsted - Not an expert, just a data point.
1999 Miata
2003 MIata
1999 Miata
2001 Kia Rio
Oh yea memories - http://www.dfwmiata.com/showthread.p...ht=#post241629
Maybe just leave it alone.
I swear after 11 Years, The Thermostat housing gets brittle on these Miata's
I maintain a 300zx Twin Turbo as well and most my friends & family's cars and have never came across a housing that weak, i had a new gasket on, new thermostat and couldn't get it to stop leaking Tightening the top and bottom little by little till they both snapped. it sealed on my miata just fine, my sisters NB was a different story
Its a simple job, i dont know why all the threads ive looked at it people are saying it hard to get to.
i took it out and cleaned it, still have the same problem. i have one ordered from the local orielys.
All you need is a 6 inch extension, a swivel socket and a 3/4 deep-socket, you don't have to remove anything and can access it from the drivers side top of the engine.