Gauge problem or overheating?

[tigernut]

Whether you get the Wells TU-5 or the "correctly calibrated" reproduction (which are not, based on the feedback I have so far), borrow or buy an I.R. gun and "shoot" the upper radiator hose just above the thermostat housing and compare that reading vs. the gauge reading at the same time so you know what the gauge is really telling you.

John has excellent advice, as always. You really need to verify your temp before worrying and going on a wild goose chase.

I built a brand new motor and used a TU-5 sensor and it has read high since installation a few months ago.

I could tell it wasn't getting as hot as the temp gauge showed (215), and finally bought an I.R. gun to verify and the actual temperature is dead on 180-185 so my sensor reads 30 deg too high (I guess the high reading could be caused by mounting the sensor directly in the head instead of the manifold, not sure).

Anyway, motors are too expensive to burn up due to faulty temp readings.

I bought this gun from Sears ($49.99 in store, it is $10 more online for some reason). It was the cheapest I could find and seems accurate when measured on another of my cars with a dead on sensor/gauge.

http://www.sears.com/sr/javasr/product.do?BV_SessionID=@@@@1931494388.1119751403@@@@&BV_EngineID=ccjkaddemijedkecegecegjdghldghh.0&vertical=TOOL&pid=03482327000&bidsite=CRAFT

Doug