I usually try to remain with Mazda parts but I realize that sometimes its worth going with other brands. I have a 1991 Miata and the thermostat is about gone. I can not remember the last time it was replaced, could be many years old. Should I get a stock Mazda thermostat from a Mazda dealer. They're about $30 with a gasket. Also,
NOTE:
My manual says the temp of thermostat is 185 deg. F, and is a WAX type, whatever that is.
Yes, this is one place where few aftermarket parts work as well as OEM. The Mazda thermostat has two flaps that open at different temperatures.
Pat,
A Mazda thermostat and gasket is At 188-193F the main valve should start to open, and should befully open (8mm/0.31" lift) at 212F. The thermostat is fitted into the housing so that spring side is inward and the smaller valve is uppermost. Fit the cover using a new gasket, noting that the gasket tab must face the top of the cover. Tighten the cover bolt and nut to 19-25 Nm (1.9-2.6 kgf m/14-18 lbf ft).
Dealer parts always seem to work best IMHO. Aftermarket is really a hit or miss.
YES. Worth the money because with a dealer part you will replace it, and it will work.
Most thermostats are a wax pellet style, the Miata thermostat is a 2 stage deal. I doubt anything you find aftermarket will match OE performance.
If nothing else, buy your hoses and thermostat from the dealer. I've already been burned by aftermarket hoses myself, but my 97 NA still has the factory thermostat and when/if it fails I will go to dealer for a replacement. As it stands right now, it warms up to just below the middle of the gauge and never deviates from that point.
Change your coolant every 2 years and the thermostat will last just about forever. Case in point, I.just sold my '97 Kia Sephia, 115k, still had the original thermostat, and it warmed up to 1 line below the middle of the gauge every time I drove it. It had a Mazda BP engine, and a Mazda G5M transaxle in it from the factory. I bought the car new, and I changed the coolant every 2 years(amongst other maintenance of course...)
Good luck with it.
Chris
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