Engine Temp Fluctuating

[ThompsonXterra]

2004 SE 4x4. 3" SL and 32" tires.

I was driving home from college yesterday on I-5N with cruise control on going around 75mph at just under 3,000rpms.

I glanced down and noticed that the engine temp needle was bouncing from the middle of the gauge to almost all the way down to cold. I turned off cruise control and slowed down to about 65mph and 2,500rpms and that stopped the needle bouncing.

Was I just pushing her too hard? Any ideas what could cause this? Thanks for the input.

 

[TheFauxFox]

Check your coolant levels.

That or your thermostat is going out.

 

[ThompsonXterra]

Check your coolant levels.

That or your thermostat is going out.

Coolant might be a little high? Its just under the recommended "MAX" on a cold engine...

 

[granitex]

my guess is that it would be the temp sensor, or the thermostat. but if it were the thermostat I would expect it to go to the hot side instead of the cold side. And how old it is the water pump.

 

[ThompsonXterra]

my guess is that it would be the temp sensor, or the thermostat. but if it were the thermostat I would expect it to go to the hot side instead of the cold side. And how old it is the water pump.

I was thinking the same thing about the temp sensor or thermostat.

Water pump is still original as far as I know. Soo 12 years old lol

 

[granitex]

waterpump should have been changed when you did the timing belt, just easier that way