Thermostat
Thread Starter
Intermediate
Joined: Nov 2013
Posts: 34
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Thermostat
Recently replaced the thermostat in my 75 Corvette. I replaced it with a new robertshaw 180 degree. I have noticed that the dashboard temperature gauge often time is reading over 200 degree. Is this common or is there a problem ??
Melting Slicks
Joined: Jun 2011
Posts: 3,114
Likes: 598
First check if there is coolant flow. If you remove the rad cap with the engine running can you see the coolant flowing. ( thermostat needs to be open . Normal operating temp ) Be caution doing this, removing the cap on a hot engine will have ~ `15 PSI and will puke coolant. It is also possible coolant will over flow.
A better test would be with a IR Temp gun. Compare the upper rad hose vs the lower rad hose temp. Usually a 15-20 degree drop.
If there is no flow Lower rad hose will much cooler then it could be the rad is plugged or very poor air flow thur the rad. ( Plugged rad fin's with bugs leaves etc)
Over advanged ignition timing can also lead to similar heat problems.
Team Owner
Joined: Jul 2006
Posts: 22,154
Likes: 4,165
From: Kannapolis NC
Depends on how much over 200. Either way, putting in a cooler thermostat won't make it run cooler unless something was wrong with the original thermostat. A thermostat controls only the minimum temp, not the max, and also allows the engine to warm up faster. Around 200 is pretty much normal, 220 is getting too hot in normal circumstances.
Like the previous poster said, verify actual temp with an IR gun. The temp senders are not exactly the most accurate measurement.
Like the previous poster said, verify actual temp with an IR gun. The temp senders are not exactly the most accurate measurement.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
The thermostat only sets the LOW running temperature of an operating engine. It stays closed until reaching its rated temp, then opens.
Once it is open, the temps MAY still climb, depending on the capabilities of your cooling system and the condition of the parts that make it up. Limed up radiator? Temps will go higher. Bad thermo fan gizmo? Temps will go higher.
You get the idea.
Once it is open, the temps MAY still climb, depending on the capabilities of your cooling system and the condition of the parts that make it up. Limed up radiator? Temps will go higher. Bad thermo fan gizmo? Temps will go higher.
You get the idea.
