Temp Gauge

[68Zproject]

Anyone running a stock console temp gauge notice it rising and at first and then falling a bit after 5-10 minutes?  I assume this is the thermostat opening?  I just got my temp gauge repaired so I haven't ever seen one work until now.  Mine falls a bit after it warms up and then goes back to rising to the static temperature.

[JohnZ]

You're seeing normal cycling of the cooling system; once it warms up and the thermostat cycling stabilizes, there's little gauge movement.

[68Zproject]

Thanks, I was a little concerned after years of trying to get this thing working, there was still a problem.

[396guy]

It should begin rising as soon as minimal registering temp is reached and climb to just above 'normal' (for your stat's degree setting) then drop to 'normal' as the stat begins to open to allow coolant flow - but it shouldn't be taking 5-10 minutes to drop to normal after stat opens.  I have an Autometer mechanical water temp in my 67 El Camino and mine only takes a few seconds after the stat begins to open (180 in my case) for the temp to drop back to 180.  If I happen to be in the middle of traffic at the time and air flow is reduced, it may stay at 200 or so until there's enough air flow to bring it back down.

[68Zproject]

I meant 5-10 minutes total after driving car.

[396guy]

Gotcha, that'd make more sense.  Depending on weather, traffic, etc. it could easily take 5-10 minutes to reach operating temperature before the stat begins to open and allow coolant flow.  The 'sudden' rush of coolant might cause the temp to drop a bit below the stat's setting as cooler coolant from the radiator initially hits the temp sensor.