water temp concern!

[Andy_350z]

drove for about an hour tonight and the water temp remained at 50/ 51 degrees. normally it gets up to 90 ish and the fans come on to cool it down. noticed the temp gauge was also closed as if engine was off. any suggestions?

[nelly1]

Either the temp. sender has developed a wierd fault or your thermostat is stuck wide open.

Did the temperature rise as quickly as normal before stopping at 50, or was it a much slower climb?

Is the engine actually getting hot?
Are the radiator hoses in and out of the rad. too hot to touch?

If you have access to the diagnostic software, you can get a 'second opinion' on the actual engine temp. as the ECU sensor is independent of the gauge sensor, and they should read to within a couple of degrees of each other.

The other (outside) suggestion would be an airlock in the cooling system.
Check your coolant level and the aforementioned radiator in / out hose temps to see if the coolant is circulating correctly.

HTH