Temp gage

[AXLE]

The temp gage on my '01 goes to exactly the 1/2 way mark. The heat seems to be OK inside the car, but I wondered if the motor was running a little too cool so I changed to a new 195* t-stat. I get the same thing now as before at the 1/2 way mark. Is this normal or am I missing something?

[Redog]

You put in the same thermo as stock.

If you wanted a cooler thermo, 180* thermo is the mark, that's what most of us have

[[ion] C2]

Half way is what it should be at.... it's 190-205 ish around the half mark.

FYI Redog using a 180 on a stock 195 will do nothing but make it take a few minutes longer to reach the normal operating temperature it was at before.

[AXLE]

Ok, it sounds normal then, thanks.

[Nate's Alero]

Originally Posted by [ion] C2

FYI Redog using a 180 on a stock 195 will do nothing but make it take a few minutes longer to reach the normal operating temperature it was at before.

that makes no sense, how would it "take longer" it opens sooner.....

[[ion] C2]

What you said makes no sense. Think about it.

[Nate's Alero]

Originally Posted by [ion] C2

What you said makes no sense. Think about it.

of course it does, a 195* thermostat opens when the coolant temperature reaches 195..... the 180* thermostat opens at 180*.... of course it will be cooler

[[ion] C2]

Dude. Go walk into a wall and come back. Don't be like the typical morons who come into AutoZone to buy a cooler thermostat to make their engine run cooler and solve overheating. That's not how it works!

The car's operating temperature is due to the cooling system's ability to radiate heat. There's a misconception that by using a colder temperature thermostat will make the car run cooler and prevent overheating. Using a colder thermostat will not prevent overheating, it will simply make it take a little longer for the car to get up to the overheating temperature. The thermostat opens (on the 2.4L) at 180 degrees F. The car runs at 185-200 regardless. The thermostat is fully open at these temperatures, leaving the chance of increase in temperature solely up to how efficient the radiator is at giving off heat, and how hard you're pushing the car, how much heat the engine is transferring to the coolant. 95% of the cooling is going to be done via the core radiating heat to the surrounding air.

[Nate's Alero]

when i was running a stock 195* thermostat, my engine was chilling around 205*....when i pushed the engine... it would go to about 215* now i'm running a 180* thermostat, and the car hangs around 186 to 195* and if i get on it, it will run to about 205, so, in a way you are right, if you constatly abuse the car, it will run just as hot, but if you have your fans tuned, and you dont beat on it, or say, highway driving, it will, WILL run cooler.

[[ion] C2]

No... the thermostat is fully open at 205 in either thermostat. Once you're at that temperature, the thermostat has NOTHING do to with the engine cooling down. The thermostat sets the minimum temperature of the engine, not the range that it normally operates at once fully warmed up. You want the car to get to normal operating temperature as quickly as possible, which GM decided was about 205 on the V6 ( the car will always run at least 5-10 degrees higher than the label of the thermostat at it's minimum when warmed up). So the thermostat is closed, allowing the coolant in the engine to heat up without a radiator, and then once it gets close to the normal operating temperature, the thermostat opens and allows radiator coolant to cool down the engine. The thermostat will close slightly if the engine gets too cool, and that slightly closed-ness will allow the hot coolant to let the engine get warmer again until the thermostat is fully opened and then the cold coolant from the radiator will contribute to cooling it down again. But once you go past a certain point where the thermostat is FULLY open, it has nothing to do with cooling and it's all up to your radiator and the rest of your cooling system to keep the engine under overheating temperature.

And like I also said in the other thread, the fans are useless!

If the radiator fans don't turn on, that is not what's allowing you to overheat. If your temperature is at 230F (after a hard few WOT runs or the like in hot weather, NOT due to a separate problem with your cooling system), the coolant temperature will drop due to the cooling system's efficiency in radiating heat. The fans seem to be useless. Having them on versus off in my car has made negligible differences in cooling down times (I can actually adjust the temperatures they turn on, so I've tested this).

Kicking on the fans isn't going to cool down an overheating engine. 95% of the cooling is going to be done via the core radiating heat to the surrounding air. This is why you'll see the most cooling done via coastdown from say, 70MPH, and not when you're standing still with the fans blasting. They simply cannot flow the amount of air that a moving vehicle can.

[widbyj]

cough cough bullshit cough cough

If "the fans are useless" then why are they there? The radiator is designed to transfer heat from the coolant to the air, with no airflow/wind the heat will soak the air around the radiator and make it ineffective. Show me ANY liquid cooled auto without fans and maybe I'll change my mind.

There is a secondary issue here also, even if you change the thermostat to a colder design the ECM monitors engine temp via a sensor and it will still try to maintain the original, higher, operating temp programmed into it. This means the fans will still be controlled towards maintaining that higher original temp and won't come on/speed up until the ECM thinks things are too hot regardless of the thermostat.

The proper solution is to install a better cooling system, Flex-A-Lite makes a slimline dual fan that fits perfectly and moves a LOT more air. Combined with their variable speed controller I can set and maintain the operating temp I choose. Besides it looks good and sounds impressive.

[a4d2a0m]

All he is saying is 95% of your cooling happens when the car is in motion. The difference the fan makes is nominal... unless you idle for long periods of time in blistering heat.

[Redog]

Sorry Nate but you are not totally correct.

All the lower thermo does is open sooner and allows the collant to cool the engine at a lower temp. The fans will kick on if the engine gets too hot.

I have a 180 thermo, but I also have an aftermarket PCM program in my car and one of the requirements is a 180 thermo.

I had a 180 thremo in My Delta. The engine would still reach 195, but it took longer to get there after 180. The fan would kick on at 197. I put a flex a lite electric fan in there with a 195 trigger. My temp gauge probe was in the back of the engine, the fan probe in the front. I figure the back of the engine was 2 degrees hotter than the front anyway The fan would turn off at 175, but once it was on, it didn't turn off until the engine was off. In weather like this, I could drive all the way home (20 minutes) and the fan would not kick on at all or not kick on until I stopped at the light right outside my delevopment

[Nate's Alero]

i get that, my PCM has the code to run the fans at 195* (i have a SPAL PWM)

so my engine runs the fans at a cooler temp

[[ion] C2]

Originally Posted by widbyj

cough cough bullshit cough cough

If "the fans are useless" then why are they there? The radiator is designed to transfer heat from the coolant to the air, with no airflow/wind the heat will soak the air around the radiator and make it ineffective. Show me ANY liquid cooled auto without fans and maybe I'll change my mind.

The fans on the dyno didn't do much for me when I was on it. Coolant temps still got way up there and stayed. Fans cannot flow the same CFM that moving at whatever MPH can, period. Fans are there to help reduce high temps (223 F + on the stock tune), but they sure didn't let the car cool down when mine got up to 240ish. Once I got outside and drove and let the air flow on the radiator, my temps immediately, SIGNIFICANTLY dropped down to normal operating temperature (around 190). It's the airflow on the radiator that does the most work. Fans IN MY OPINION are useless.

Originally Posted by widbyj

There is a secondary issue here also, even if you change the thermostat to a colder design the ECM monitors engine temp via a sensor and it will still try to maintain the original, higher, operating temp programmed into it.

You don't even know what you're talking about, yet you're saying it as if it's fact. The PCM knows engine temperature, but it's not going to "try to maintain the higher temperature." How exactly do you suggest the PCM does this? Is there an electric solenoid that forces the thermostat closed? Is there a valve that shuts off the radiator?

Have you ever looked at the tune? Seriously.

Originally Posted by widbyj

This means the fans will still be controlled towards maintaining that higher original temp and won't come on/speed up until the ECM thinks things are too hot regardless of the thermostat.

Oh yeah? The factory tune sets the fans to turn on at 223 F. Show me where it waits longer because a 160 thermostat was used versus the stock 180 (both allowing the engine to operate at it's normal 187-198ish area once it's fully warmed up.

THE THERMOSTAT SETS THE MINIMUM OPERATING TEMPERATURE OF THE ENGINE WHEN IT IS FULLY WARMED UP, NOT THE OPERATING TEMPERATURE.

If you put a lower temperature thermostat in, the car will still get up to the temperature it has been getting up to. It may just take longer for it to get there. The point of a thermostat is to allow the car to get up to the proper operating temperature as quickly as possible. It closes off the radiator's input until a certain temperature, and then it opens to fully open 7-10ish degrees beyond that point, at which point it is fully open. So if you're beyond that 10 degree margin higher than what the thermostat is set to open at, it's not going to do ANYTHING to keep the car cooler. Same with a colder thermostat, the car will be running at the same temp as the higher one, if the normal operating temperature of the engine is higher than both of them.

Originally Posted by widbyj

The proper solution is to install a better cooling system, Flex-A-Lite makes a slimline dual fan that fits perfectly and moves a LOT more air. Combined with their variable speed controller I can set and maintain the operating temp I choose. Besides it looks good and sounds impressive

Yeah because the way the fans sound is so cool. Sure, they're fans are nice, but a "better cooling system" is a higher output water pump, a much nicer radiator like Milzy's bar and plate all aluminum thicker one, and a new OEM temperature thermostat.

[a.graham52]

Originally Posted by widbyj

cough cough bullshit cough cough

If "the fans are useless" then why are they there? The radiator is designed to transfer heat from the coolant to the air, with no airflow/wind the heat will soak the air around the radiator and make it ineffective. Show me ANY liquid cooled auto without fans and maybe I'll change my mind.

There is a secondary issue here also, even if you change the thermostat to a colder design the ECM monitors engine temp via a sensor and it will still try to maintain the original, higher, operating temp programmed into it. This means the fans will still be controlled towards maintaining that higher original temp and won't come on/speed up until the ECM thinks things are too hot regardless of the thermostat.

The proper solution is to install a better cooling system, Flex-A-Lite makes a slimline dual fan that fits perfectly and moves a LOT more air. Combined with their variable speed controller I can set and maintain the operating temp I choose. Besides it looks good and sounds impressive.

caddilac advertised at one point an engine (i belive it was the northstart maybe) that could run without coolan for a longer then normal amount of time. i dont know how true this is but its what iv herd. just adding this for shits and giggles.

[jayson_waltz]

seriously people? the temp the thermostat is rated at is just the temp at where it opens, thus letting the coolant flow through with the rest in the radiator. That is the ONLY task the thermostat has, opening at a set temp. It has nothing to do with how hot the engine runs, that will always stay the same.