Engine temperature gauge instantly hit maximum

[TheGodfather]

Yesterday, after driving for under 5 minutes I noticed my engine temp gauge was at max in the red. So I immediately slowed down, and pulled over with in a minute. I shut off the vehicle and re started. The needle returned to normal, which under the conditions was still cold, just above the blue.

Conditions:

• -17 degrees celsius outside
• engine was still cold prior to incident
• car had only been running ~5min

Based on these facts, I doubt the gauge was accurately depicting the true engine temp.

So could my engine temp sensor be failing? This is the first time this has happened, and it has not re occurred yet.

On a side note, a couple of months ago, I noticed that after 1+ hours of highway driving, my gauge was still not reading out at optimal engine temp, it was slightly on the cold side. Again, faulty sensor?

Thanks in advance for any advice,