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Do my fan settings look right for 160 Tstat in HPT??
Can you guys tell me if these fan settings are correct for a 160F Tstat and just in general, using HP Tuners? I NEVER heard my high speed fan kick on even with coolant running up to 230F!
This is exactly how the tuner had it set up. Something is not right if my high speed fan mode never kicks in...
Enable speed is 30mph
Disable speed is 35mph
The 90 mph off exists in my EFI Live but is named 'Fan1 and Fan2 shutoff'. Not sure of it's function. Your temp settings are nowhere near normal.
Enable speed is 30mph
Disable speed is 35mph
The 90 mph off exists in my EFI Live but is named 'Fan1 and Fan2 shutoff'. Not sure of it's function. Your temp settings are nowhere near normal.
Hmmmm - are those settings for a 160 Thermostat or stock? I'm not sure if that even makes a difference?? The reason I'm digging into this is because I was in a very long car cruise (over 1hr 30m) and it was constant stop and go with speed not exceeding 20mph max! Stayed in 1st and 2nd gear the whole cruise
(Sidenote : By the time I reached down town, I had lost 60% brake and almost all clutch I have since changed to high temp fluid instead of the Dot3 that was in there..)
I am no tuner but I will see what I can figure out on the fan settings from you guys input so far.
Hmmm that does make sense to me but what got me confused now is, as some of the other guys posted their stock settings, the enable speed is 30 and disable speed is 35. So won't this make the fans come on at 30 and turn off at 35+ ??
Yes, assuming the coolant temp, or the A/C pressure aren't already commanding the fans on. This won't override a different legit request for fans, only the one based on vehicle mph.
I can't say as I understand this 30/35mph business. I'll have to think on it some more. But, that's obviously not the only possible way to trigger the fans on.
EDIT:
It could be that the engineers want to cycle the fans periodically to keep them from seizing up in cold climates, where the A/C is never used and the coolant temp seldom gets very high.
Yes, assuming the coolant temp, or the A/C pressure aren't already commanding the fans on. This won't override a different legit request for fans, only the one based on vehicle mph.
I can't say as I understand this 30/35mph business. I'll have to think on it some more. But, that's obviously not the only possible way to trigger the fans on.
EDIT:
It could be that the engineers want to cycle the fans periodically to keep them from seizing up in cold climates, where the A/C is never used and the coolant temp seldom gets very high.
Negative. The 30mph setting re-enables fans after 35mph shutoff. Fans run from 0 to 35mph by eng temp settings where they shut off and when you slow down to 30mph fans are allowed to run.
Negative. The 30mph setting re-enables fans after 35mph shutoff. Fans run from 0 to 35mph by eng temp settings where they shut off and when you slow down to 30mph fans are allowed to run.
a - I get that the A/C can request fan on at any road speed. b - I get that coolant temperature can request fan on at any road speed.
The question is: c - Why to the fans enable at 30mph (assuming that neither the A/C nor the engine temperature are already requesting fans) and then the fans turn off at 35mph? At least this is the intended operation that the tuning software suggests to me. I haven't personally verified that the fans actually function this way.
Obviously, all three scenarios a, b & c (A/C, coolant temperature & road speed) can independently request fan on operation. I am just inquiring about the logic of scenario c.
Ok I will set them at the 30 and 35 setting. My tuner did a fantastic job on the tune so Idk how they left it 0 on both but then again they had those huge fans blowing in front of the car when tuning, so Idk what really happened there...
No, not correct. c allows a and b to command the fans on.
Above 30 there is enough airflow the fans don't help so they are switched off and allowed to freewheel.
I agree that there is likely sufficient airflow through the radiator at and above 35 mph, so long as it's a low load, low ambient temperature and low coolant temperature situation. That aspect of the fan control logic makes sense. But, why wait until 30 mph to turn the fans on? Why not 25 mph, or 20 mph, what's so special about 30 mph? What is the logic in waiting until 30 mph is reached? If GM figure that the engine just doesn't make enough heat below 30 mph to justify a fan on request, why even include a fan on request which is based solely on vehicle speed and instead simply rely on engine coolant temperature to determine when the fans need to ramp up?
EDIT:
Oh, and please elaborate on how scenario c allows either the A/C, or the coolant temperature to request the fans on. Are you suggesting that the fans could not otherwise operate, unless this bit of vehicle speed logic were not inserted? In other words, that if scenario c were disabled via HP Tuners, for example, the fans would not/could not ever run?
I'm going to pull up the wiring diagram to see if I find any clues there.
I agree that there is likely sufficient airflow through the radiator at and above 35 mph, so long as it's a low load, low ambient temperature and low coolant temperature situation. That aspect of the fan control logic makes sense. But, why wait until 30 mph to turn the fans on? Why not 25 mph, or 20 mph, what's so special about 30 mph? What is the logic in waiting until 30 mph is reached? If GM figure that the engine just doesn't make enough heat below 30 mph to justify a fan on request, why even include a fan on request which is based solely on vehicle speed and instead simply rely on engine coolant temperature to determine when the fans need to ramp up?
EDIT:
Oh, and please elaborate on how scenario c allows either the A/C, or the coolant temperature to request the fans on. Are you suggesting that the fans could not otherwise operate, unless this bit of vehicle speed logic were not inserted? In other words, that if scenario c were disabled via HP Tuners, for example, the fans would not/could not ever run?
I'm going to pull up the wiring diagram to see if I find any clues there.
It is not an issue of high or low heat load on the engine cooling system, it is air flow. GM and Harrison Radiator Engineers determined decades ago that above a vehicle speed that ram air flow exceeded the air flow from the electric fan(s). This may go back way too many years for my memory but I do recall some test work in our wind tunnels that showed that above a level of vehicle speed (that means ram air flow), running the fans actually led to higher engine coolant temperature under high engine heat load. So if the fans are not helping the engine cooling system above 35mph AND they do draw significant wattage (that electrical load requires engine power and fuel to drive the alternator), then shut them off when not needed.
Regarding heat load, keep in mind that very high heat load can occur at low vehicle speeds when vehicles are climbing steep grades while pulling a maximum rated trailer load. Think about the mountain passes in the dessert southwest. They are miles long, the temperature is over 100 degrees, and people are hauling big *** trailers.
@bookyoh So does this explain why my coolant temps got up to 230F during this 1hr 30 min car cruise (stop and go every 20 sec to 1 min, speed averaging around 15 to 30 mph the whole time) and is it also the tune settings for the fans (the 0mph setting on both ON and OFF settings)? Otherwise is there any other way I can prevent this from happening or just stay away from long car show cruises?!
Also, I had originally put DOT3 fluid in the car which got too hot by the time I reached the end of the cruise and I lost most of my brakes and almost all my clutch at the very end as I parked the car in the downtown show area . I have since changed the fluids to Amsoil Dot 4 High Temp fluid...
@bookyoh So does this explain why my coolant temps got up to 230F during this 1hr 30 min car cruise (stop and go every 20 sec to 1 min, speed averaging around 15 to 30 mph the whole time) and is it also the tune settings for the fans (the 0mph setting on both ON and OFF settings)? Otherwise is there any other way I can prevent this from happening or just stay away from long car show cruises?!
Also, I had originally put DOT3 fluid in the car which got too hot by the time I reached the end of the cruise and I lost most of my brakes and almost all my clutch at the very end as I parked the car in the downtown show area . I have since changed the fluids to Amsoil Dot 4 High Temp fluid...
Shutting the fans off above 35mph should have no impact on city traffic driving; i.e. extended low speed stop and go like traffic. If I drive my bone stock ‘99 in stop and go city traffic (or a parade or a cruise in) for 90 minutes on a hot summer day, my coolant temperature will rise and fall as the fans cycle on and off; and that is completely normal. So what if it reaches 236 degrees and then drops as the fans kick in to high speed. There is nothing wrong with that.
Your brakes and clutch sound weird unless you were “sprinting” from stop to stop with lots high rpm starts and hard stops.
This is just a followup to provide the logic for the cooling fan(s) operation. Per the WSM for the 2004 MY: The low speed cooling fan is commanded on when the coolant temperature reaches 108° C (226° F). It is turned off if the coolant temperature lowers to 104° C (219° F). The high speed cooling fan is commanded on when the coolant temperature reaches 113° C (235° F). It is 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 fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
So, it would appear that the 30/35 mph road speed settings are only relevant when the A/C is operative. This description would suggest that we should expect the fan to run at all road speeds below 35 mph (given that the A/C is on and the coolant temp is above 185 F). Therefore, I would interpret the 30 mph input as a hysteresis cushion. In other words:
Given the necessary conditions, the fan will run at low road speeds and then switch off once 35 mph is reached. On coast down from high road speeds, the fan will switch back on at 30 mph and stay on at low road speeds until 35 mph is once again reached.
When the A/C is on and the coolant temperature reaches 85° C (185° F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
So, it would appear that the 30/35 mph road speed settings are only relevant when the A/C is operative. This description would suggest that we should expect the fan to run at all road speeds below 35 mph (given that the A/C is on and the coolant temp is above 185 F). Therefore, I would interpret the 30 mph input as a hysteresis cushion. In other words:
Given the necessary conditions, the fan will run at low road speeds and then switch off once 35 mph is reached. On coast down from high road speeds, the fan will switch back on at 30 mph and stay on at low road speeds until 35 mph is once again reached.
The 30/35 mph settings are always relevant.
Cooling fans will run, both low and high speed, below 185F controlled by A/C pressure.
See HP TUNER and EFI LIVE inserts in above posts. From 2000 FSM. Quote from first paragraph. "The PCM also uses A/C refrigerant pressure sensor to enable the engine coolant fans when the A/C refrigerant pressure is high."
12-23-2023, 06:56 PM
Do my fan settings look right for 160 Tstat in HPT??
I have since changed to high temp fluid instead of the Dot3 that was in there..)
fluid in the car which got too hot by the time I reached the end of the cruise and I lost most of my brakes and almost all my clutch at the very end as I parked the car in the downtown show area 