i have a thermostat that is unused with N3A1 NTC 82deg C on it. any ideas?

 

i think it might be an fd thermostat.

 

FD and s5 are the same, a 52mm thermostat and the updated PN would probably be an n3a1 (fd part prefix). s4 uses 54mm.

 

hmm really.... actually since my last post i tested when it opened. now i just used a meat type thermometer in a pan of water, but it didnt open till about 190 so i dont think its working properly, but it did open fully at about 200. i dont know.

 

They are not supposed to open fully at the rated temp, only to begin to crack open. Remember that the water on the underside is under pressure from the pump and engine temps when it opens, so a small crack allows a fair amount of coolant through. IF it opened all at once, temps would not be regulated as closely...they would vary more.

IT shoudl begin to crack open around 185 and be fully open around 195+, so I would say that is dead on. Stock thermostats usually work pretty much perfectly up until the point that they stick and fail altogether.