To begin with my car started overheating about 2 weeks ago. I changed the thermostat it was good for a a couple of days then overheated again. I then proceeded to change the fan to a GT500 one still overheated. I took it in to a shop and they said it was my water pump so I got it changed still overheats. It funny cause I live in AZ and I know cars get hot but during the day it runs at 214and like 222 when I stand still but at night it runs well past 230 if I’m at a stand still. If I hit the gas it will drop the temp down I have lowered down the temp for the fan to kick in. I have a feeling that there might be air in the system I have only done headers does any one have any idea what might be the cause? Any advice on what I can do to make it run a little cooler.
My apologize if I posted it on the wrong thread.
What year is the car ? Is it a V6 or V8? Auto or manual ? U said u changed the T stat and it was good for 2 days, then went to hell. You might want to swap the T stat..again..to a new one. Mine is 190 F , oem T stat, on my 2010 GT auto..with small Roush M90 blower + LT's.
You said the low and hi speed fan kick in where they should. That eliminates the resistor, relay etc. I'm assuming you have something plugged into the OBD port to measure temps. On my 2010, with 3 x aeroforce gauges plugged in, the actual oem sensor measures CHT's (CYL head temps). The 'coolant' temp on both the aeroforce gauge ( and also display on the dash) is an inferred reading, using some alogorithm + ECU etc. The aeroforce reads both...simultaneously. Using my SCT-X3 I can set the low and high fan to kick in at a huge range of temps. In fact the range overlaps. (IE: the hi speed fan can be made to kick in at a lower temp vs the low speed fan).
At idle, in the driveway, temp comes up to aprx 204 F, then low speed fan kicks in...and temp drops down to 194 F..and low speed fan kicks off. Temp come back up to 204 F..and again, low speed fan kicks off. That cycle just repeats itself. Driving around town,the low speed fan never kicks in.
In your case, what's baffling is nighttime is bad news, but daytime is good.
When the water pump was replaced, did you have the entire cooling loop VACUUUM filled with distilled water + glycol ??