Hey everyone,

I'm not sure if this has been covered before, but I found out about this awhile ago and just rediscovered it, so I'd like to share. For those of you switching over to a GM-style of sensor, there's an M12x1.5 thread sensor that basically drops into the back of the S4 FC water pump housing (I don't remember if S5 or FD is the same, but it might be). I don't know what cars it comes from, but the Delphi part number is 12146897. $10-12 from what I've seen. It should have the same temperature calibration curve as other GM sensors, and dimensionally, the sensor is very close to the original FC unit. Probe length is the same and it also takes a 19mm wrench. The main difference is that it threads a little deeper, and while that's not a problem, you may want to run a tap through to clear the junk at the bottom. Hopefully this saves people a little headache when putting together their squirt builds.



(Left is the Delphi sensor, right is the FC sensor)



(Delphi sensor in the pump housing)



(Specs on the sensor and its matching connector)



(Calibration curve)