[Z06] engine temps
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Joined: Nov 2021
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From: NJ
engine temps
I have a C5Z with 14K miles and minimal work done (headers, air box and a dyno tune). The last owner says he put in a 170 thermostat but it still runs hot in the warm days. I've never let it get above 190 before I turn the AC on to bring the other fan into play. My question is what is the normal operating temp of this LS6 engine normally? Should I let it get above 190?
Safety Car
Joined: Mar 2017
Posts: 3,749
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From: Orlando Florida
Easily accessible info. From an old Evil Twin post:
Depending on the model year...
For later model years:01-04
The low speed cooling fans are commanded on when the coolant temperature reaches 108°C (226°F). They are turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fans are commanded on when the coolant temperature reaches 113°C (235°F). They are turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fans will be turned on at vehicle speeds less than 56 kPh (35 mph).
For early model years:97-00
Low speed fans come on at 219,high speed fans come on at 228,low speed with a/c on...
Depending on the model year...
For later model years:01-04
The low speed cooling fans are commanded on when the coolant temperature reaches 108°C (226°F). They are turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fans are commanded on when the coolant temperature reaches 113°C (235°F). They are turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fans will be turned on at vehicle speeds less than 56 kPh (35 mph).
For early model years:97-00
Low speed fans come on at 219,high speed fans come on at 228,low speed with a/c on...
Race Director
Joined: Oct 2004
Posts: 12,795
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I have a C5Z with 14K miles and minimal work done (headers, air box and a dyno tune). The last owner says he put in a 170 thermostat but it still runs hot in the warm days. I've never let it get above 190 before I turn the AC on to bring the other fan into play. My question is what is the normal operating temp of this LS6 engine normally? Should I let it get above 190?
Le Mans Master
Joined: Oct 2007
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From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
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Just running a lower thermostat wont do much if the fans come on at the original temperature. Your temps are perfectly normal though so you shouldnt be worried.
If you want to lower them you can have the fans programmed to come on sooner by a dyno or mail order tuner. I use a stock thermostat and had the fans programmed to come on sooner. I dont see over 195°F on the street and about 220°F on track with the stock radiator.
If you want to lower them you can have the fans programmed to come on sooner by a dyno or mail order tuner. I use a stock thermostat and had the fans programmed to come on sooner. I dont see over 195°F on the street and about 220°F on track with the stock radiator.
