Slow Temperature Increase

[LeBron]

Dear All,

I noticed that the temperature was going up very very slowly this morning, it took about 20mins to hit 90 degrees.
After hitting 90, temp came down to about 85 for about a minute before going back to 90 and was consistently at 90 after that.

30min drive was smooth, no problem in fuel consumption too.

May I know what could be the problem?

Thank you.

[kite]

Failing coolant temp. sensor or a thermostat stuck open....

[RJS_90q]

I agree with Kite. These would be the most likely reasons for the problem. A further possibility may be that the electric radiator fan is starting to soon, resulting in the engine staying too cool...

[LeBron]

Thanks for the prompt replies.
It turns to be a faulty fan.

Cheers