The thermostat only controls the minimim coolant temp that the temp comes up to. One the thermostst is open the temp can continue to go up depending on the outside temperature and rate of airflow through the radiatior. Putting in a lower temp thermostat will keep the temp down in cool weather or on the highway with good airflow through the radiator. But it will not help in hot weather and in town driving. You need to turn the fan on at a lower temp if you want to keep the temp down under those circumstances. Even if you turn the fan on at a lower temp the factory radiators do have their limitations and beyond that you would need an aftermarket radiator.
I believe the fan seems to come on at a much lower temp on the C6s than the C5s.
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SOLD 2002 Z06 Millenium Yellow/black. All options except museum delivery & BSM
The thermostat only controls the minimim coolant temp that the temp comes up to. One the thermostst is open the temp can continue to go up depending on the outside temperature and rate of airflow through the radiatior. Putting in a lower temp thermostat will keep the temp down in cool weather or on the highway with good airflow through the radiator. But it will not help in hot weather and in town driving. You need to turn the fan on at a lower temp if you want to keep the temp down under those circumstances. Even if you turn the fan on at a lower temp the factory radiators do have their limitations and beyond that you would need an aftermarket radiator.
I believe the fan seems to come on at a much lower temp on the C6s than the C5s.
That's not quite true. First, the C6 fan don't come on until a much higher temp than the C5's, you can't even get them to come on with tuning till 192. Also, the C6 can run cooler with a lower temp thermostat because it would be open, allowing flow to the radiator when the stock one is still closed. With a 160 thermostat and retuned fan settings you can get the car to run about 185 to 195 even in stop and go driving. With the stock thermostat, which doesn't even go fully open until well over 200 degrees (some not till 212), the car can't cooldown even though the radiator and fan has enough capability.
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That's not quite true. First, the C6 fan don't come on until a much higher temp than the C5's, you can't even get them to come on with tuning till 192. Also, the C6 can run cooler with a lower temp thermostat because it would be open, allowing flow to the radiator when the stock one is still closed. With a 160 thermostat and retuned fan settings you can get the car to run about 185 to 195 even in stop and go driving. With the stock thermostat, which doesn't even go fully open until well over 200 degrees (some not till 212), the car can't cooldown even though the radiator and fan has enough capability.
I do not know the fan on temps for the C6 but for 2002 C5 the low speed fans come on @ 219 and the high speed comes on at 228. So in traffic in hot weather 220+ in not uncommon. The C5 thermostat is 195 although my C5 stayed at 190 on the highway so it opend sooner than 195. I can't find a C6 thermostat on the GM parts sites but NAPA says the OEM thermostat is 186.
I have not seen over 205 in my C6 so I believe the fan may come on at a lower temp than the C5. . As I said once the thermostat is open it has no way to keep the temp from going up., That is up to the heat generated by the engine the temp and air flow through the radiator and the ability of the radiator to dissapate heat.
Since you say the C6 will run 185-195 in stop & go traffic a 160 stat will do nothing for you except keep the engine too cold to boil off contamanents in the oil when in cold weather, on the highway etc. If the stock stat is really a 186 there is no need to change the stat to run 185-195 if you change the fan settings. However you say you can't get the fan to come on below 192. If that is the case the car won't run below 192 in stop & go traffic no matter what thermostat you put in.
You're missing a couple of things. Yes the stock thermostat STARTS to open at 187 degrees, but opens very slowly and isn't fully open till well over 200 degrees. That restriction to coolant flow is why the C6 runs hot, the radiator and fan are fully capable of keeping it cooler. With a 160 thermostat running above 45 mph (or so) you don't even need the fan to come on to maintain temps in the high 180's because you have both coolant flow and airflow. You're operating in a range where the stock thermostat isn't fully open but the 160 is. Once you get to 210+ then both thermostats are fully open and they won't differ in restriction but resetting the fan to higher percentages will pull the temp down better and faster with the 160 because it will stay open where the stock one will start closing down.
As far as contaminants, the oil life monitor takes into account the oil temp and suggests changing the oil sooner when it's run cooler AND an occasional WOT run will get the oil hot as hot as you like, not that running with coolant temps in the 180's is too cool anyway.
With the C5 you could run the fans as low as you like, I had mine start low speed operation in the 170's, you can't do that with the C6. Still, running the fan at 40% @ 192, 60% @ 194, and 90% @ 196, you can maintain temps in the low to mid 190's (with a 160 stat).
If you reset the fan percentages and keep the stock stat you are setting the two pieces to work against each other. The fan will be running trying to cool the car while the stat will be closing to try and get the car hotter. You'll end up with the fan running all the time and still run hot.
I understand what you are saying. I think a good solution would be if you could find a stock temp stat that opens faster as the temp goes up or if that can't be found I would rather use a 180 stat. I believe 160 is just too cold for a street car. The oil temps in my Z already seem to run a bit on the cool side anyway.
Do you know what the stock fan settings are for the C6 and for the C6 Z06? And are they different for different years.
You can get a Mr Gasket 180 degree thermostat at just about any parts store, special order for a "late" LS1 (part number 6368). Will take a few days and cost $17.00.
I will watch my winter temps, might switch to one myself.
You can get a Mr Gasket 180 degree thermostat at just about any parts store, special order for a "late" LS1 (part number 6368). Will take a few days and cost $17.00.
I will watch my winter temps, might switch to one myself.
I might check and see if I can tell at what temp the fan comes on. If it comes on at a low enough temp I might try a 180 since that are not hard to change.
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2002 Z06 Millenium Yellow/black. All options except museum delivery & BSM
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