(i have searched)

i have been wondering for a while now because every answer is different.
i have been told the engine fans kick on at around 190 F or 200 F

well mine kick on at 221 F weird number right? well for fear of messing up something i would turn on the ac and that in turn would kick on the fan a few seconds after.

my question is what the title says, when are the fans supposed to turn on? is my temperature normal?

 

Mines turn on at 223

06 ss/sc

Mines turn on at 223

06 ss/sc

 

mine usually kick on at 196

 

the fans will come on at different times with AC on/off. its dictated by system pressure.

remember that fan1 comes on earlier then the 2nd, but thats the one you "hear" (speeds ramp)

 

oh okay, so i guess the 121 F is normal. and i knew about the ac pressure thing, thats the reason i would turn the ac on, so it would kick on the fan

 

would it make sense to lower the fan turn on point? I know know of the most basic important mods when I had my GTP was to put a 180* thermo in and set the fan turn on point to 185* in the pcm, and also have the fans run for 3 min after the car is shut off if the temp is above 180*.. Or does that stuff not really matter with the LSJ?

 

when a score is made against the opposing team..

 

way to provide useful information!

 

Mine kicks on at 217 F

 

mine too..off at 190*

 

mine comes on a 200... then again my car stock seems to cruise at 183ish.

 

Mine was running around crazy at usual temps of about 210 (city sludgery driving) the fan 2 didn't come on till I would hit 232 and that scared me.... now they come on a bit earlier since my tuner had his way with it.

 

damn.. i was freaking when mine hit 215 one day lmao

 

When the fans come on/off depends on the car as well as the tune.



For the LSJ:

The PCM commands Low Speed Fans ON under the following conditions:

• Engine coolant temperature (ECT) exceeds approximately 106°C (223°F).

• A/C refrigerant pressure exceeds 1 310 kPa (190 psi).

• After the vehicle is shut off, the ECT at key-off is greater than 140°C (284°F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes.

The PCM commands High Speed Fans ON under the following conditions:

• ECT reaches 110°C (230°F).

• A/C refrigerant pressure exceeds 1 655 kPa (240 psi).

• When certain DTCs set

When the request for fan activation is withdrawn, the fan may not turn OFF until the ignition switch is moved to the OFF position or the vehicle speed exceeds approximately 10 mph. This is to prevent a fan from cycling ON and OFF excessively at idle.

You can tune the fans to come on at lower settings via the tune. On my SS/SC I had the fans kick on low speed at 199 and high speed at 210.




For the LNF:

Cooling Fan Description and Operation

Cooling Fan Control 2.0L

The engine cooling fan is a variable speed fan. The engine control module (ECM) controls the fan speed by sending a pulse width modulated (PWM) signal to the cooling fan control module. The cooling fan control module varies the voltage drop across the engine cooling fan motor in relation to the PWM signal. The cooling fan speed can be adjusted from 10 percent to 94 percent duty cycle. 94 percent is considered high speed fan.

The ECM commands fans ON under the following conditions:

Fan Control During Engine Operation (Engine ON)
• Fixed 94 percent duty cycle commanded when the following conditions are met:

- Engine oil temperature is greater than 140°C (284°F).

- AT transmission temperature is greater than 140°C (284°F).

- Intake air temperature is greater than 65°C (149°F).

- Engine coolant temperature sensor faults have been detected (electrical or rational).

• Variable duty cycle from 15-95 percent is commanded when:

- From all available requests, the maximum requested duty cycle is selected and commanded.

- Dependant on engine coolant temperature, 0 percent up to 92.9°C (199.22°F). Then 15 percent at 93°C (199.4°F) to greater than 94 percent by 121°C (249.8°F).

- Dependant on A/C pressure sensor, 0 percent up to 10,979 hPa. Then 15 percent at 10,980 hPa to greater than 94 percent by 23,529 hPa.

- Fans commanded off during running operation when the above conditions are not met.

Fan Control During After-run (Engine OFF)
• Fixed 36 percent duty cycle commanded after shut-down when the engine coolant temperature at shut-down is greater 101°C (213°F).

• Fixed 60 percent duty cycle commanded after shut-down when the engine coolant temperature at shut-down is greater than 108°C (226.4°F).

• Fans commanded OFF during after-run when:

- System voltage is less than 11.5 V.

- After-run time is greater than 420 seconds.

- Coolant temperature drops below a variable threshold

Currently Trifecta can change the fan controls, but HPTuners cannot.

 

thats good to know, thank you for the answer

 

Actually its a bad idea to do that. If you lower the operating temperature of the engine, the internal parts may not expand to the tolerances they were designed to operate at.

The sole purpose for going with a cooler thermostat was to decrease engine temperature as read by the ECM. By doing this the ECM would advance spark and richen the A/F ratio slightly because its seeing colder temperatures. Bypass the issues caused by a colder thermostat by getting a tune and run it hotter.

Sure you're less prone to knock when the engine is cooler, but if it was better for longevity and efficiency, GM would design these engines to run much cooler.

 

That's what I wanted to know, thanks man. Every engine has an optimal range to operate in for best performance, I know some old big blocks run best with water temps around 160*.

With a GTP being a s/c car that did not come with an intercooler, running a colder thermo/keeping the coolant cooler made the car run better and less prone to knocking. It makes sense that on an intercooled car that the water temps would matter as much as long as they were in normal operating range.

Thanks for clearing that up

 

how are you all hitting these high ass numbers?! the highest i ever hit was 207

 

summers on the east coast (probably any coast, and that north) hit a high of like 90 degrees. In stl, at 105 temp outside my car doesn't find it easy running cool.

 

yea, talk about 113 in texas.

this is when i was sitting though.

my driving temp was 183

 

Highest I hit was 220 and my cars new... thats when the 2nd fan turned on so...

stupid heat and traffic suck...

 

the highest i've ever seen is 207 and that was during some serious mountain attacks