[drewspr00]

I've just been through a crazy ordeal with a dealership and I'm hoping you guys can help me with an issue to keep me from having to go back to the dealership once again without them fixing my issue. I won't get into details, nobody likes reading complaints anyway.

Long story short, I just had a thermostat replaced by the dealership. Now my car's fan blows at med-high speed when warmed up at idle and anytime I'm driving. Coolant temp shows just below the 210 mid mark and oil temp stays at 200. The next morning after it cooled off I looked under the hood at the coolant tanks. Top tank was less that half full and the bottom tank was completely empty. I called the dealership back and told them they didn't refill the coolant after installing the thermostat and the fan was blowing crazy loud even at idle with temps on the high side. They said oh yeah it just needs to be burped, bring it by and we'll take care of it. I did the next day, and they had the car for 20 minutes and gave it back. No coolant added. Same issue. (No idea how they can say it needed the air burped when the air is in the coolant tanks.) So I went and purchased some dexcool and filled the top tank. I let it run and added more. In all I added just under a gallon of coolant. Top tank is now full, bottom tank is half full. Still dealing with the loud fan issue.

Does anyone know what I need to do from here? Fan has always been super quiet unless I was really pushing the car and I seem to remember my coolant temp staying around 180. Any thoughts?

Thanks

[ctrlz]

Factory thermostat is 90 C or 194 F. It is stamped in Celsius.
Operating temp is 95 C or 203 F.

I suspect they installed a 92 or 94 C thermostat. get the part # off the invoice.

recent thread:
https://www.camaro6.com/forums/showt...php?p=11127090

[drewspr00]

Thanks for the reply ctrlz. I'll check my invoice and report back. If that's not the case, does anyone know the best way to get air out of the coolant system? Now that I added coolant to the correct level there actually might be air in the system that needs to be burped.

[drewspr00]

I’m looking at my invoice now. I’m showing 12674634 (s) outlet for the thermostat replacement. I’m not finding much information about if it might be the higher one.

[SSgtSS1LE]

Certain resistance conditions with IAT or ECT sensors may cause unwarranted cooling fan ON for no apparent reason and without any component or system DTCs set, the IAT or ECT sensor may be skewed.

Low coolant level may cause ECT sensor incorrect temperature readings.

Check the Mass Air Flow (MAF) electrical connector and make sure it is fully seated.

The sensors listed below are integrated within the mass air flow/multifunction intake air sensor:
IAT sensor 1
IAT sensor 2
Humidity sensor
MAF sensor
BARO pressure sensor

[drewspr00]

Well, I think I'm going to have to head back to the dealer and see what they say. Coolant levels are correct, and I've done every kind of burping I know how to do. Fan is quiet until it reaches the 200 degree mark and then it runs at high speed. Our weather has been in the 40s lately and it still runs like crazy. I shouldn't be hearing my fan over my borla exhaust.

[ctrlz]

This post shows exactly where my temp sits.
https://www.camaro6.com/forums/showp...8&postcount=14

Unless yours is going higher, I think there may be a problem with the fan control module.

[SSgtSS1LE]

I believe your issue is electrical and not related to low coolant level.

I wonder if the new thermostat is defective?

A quality ODB2 scan tool and not a code reader can help you determine what the sensors are telling the Engine Control Module (ECM).

From the service manual:
Cooling fan speed is affected by many different conditions and can be adjusted from 20% to 99% duty cycle (PWM), 90% is considered high speed fan. When multiple cooling fan speed requests are received, the ECM uses the highest cooling fan speed of all the requests. The ECM commands the cooling fan ON under the following conditions:

1. Cooling fan duty cycle starts when engine coolant temperature reaches approximately 214 F and reaches high speed at temperatures above 228 F.
2. Cooling fan duty cycle starts when A/C pressure reaches approximately 141 psi and reaches high speed at A/C pressures above 305 psi.
3. At transmission oil temperatures above approximately 234 F the cooling fan duty cycle will be commanded to high speed.
4. After the vehicle is shut OFF, if the engine coolant temperature at key-off is greater than 235 F or the A/C pressure is greater than 334 psi, the cooling fan duty cycle is set to 55%, low speed. If the coolant temperature drops below 225 F and the A/C pressure drops below 261 psi, the fan will shut OFF.
   The fan will automatically shut OFF after 300 seconds regardless of coolant temperature.

So, now knowing how the cooling fan operates we can try to figure out what the problem is.

1. Ensure the engine coolant temperature sensor connector is plugged in.


2. I doubt the A/C pressure is the cause, but still check the sensor connection near drivers side radiator side tank just below the air filter.


3. I doubt the transmission oil temperature sensor is the problem unless the dealership changed transmission fluid, but check the sensor connection.

[drewspr00]

Ok guys, I have an update. I have the problem solved. I appreciate everyone's help on this issue.

I took you guys' advice and logged my trip home yesterday with HP tuners. What I was noticing was that my Engine Coolant Temp (SAE) stayed between 192 and 198 and my Fan Desired was between 50% and 90% the whole time. I've had the car tuned for E85 and some basic upgrades with Ted at JRE, so I went to the tune to look and see what was going on there.

Stock:


JRE Tune:


I've never had any issues with the fans until the thermostat replacement. I looked at my old logs from when I was tuning for E85 and my temps stayed between 180 and 190. My best guess is that like some of you had mentioned, the dealership replaced my thermostat with one that opens at a warmer temp than what was stock. I edited my tune to have the fan curve be a lot less steep and uploaded it last night. I ran it around town pretty hard and then to work this morning and temps stayed the exact same as they were and if the fan turned on I definitely didn't hear it. I went even went through a drive thru for breakfast and wasn't asked to turn my car off so they could hear me this time (yes, that's how loud that fan has been at full blast).