Feedback, concerned about temperature.

[Max70]

So, I need a little feedback here as my mind is not at rest.

I just changed the thermostat housing to the aluminum one (which included a new thermostat and sensor) and the coolant to blue G-48 (as per my previous post about coolant)

Now my concern is that before changing these, I used to notice that every time I switched on my AC (which in turn switches the radiator fan on ) the temperature used to drop a little, so the needle on the temp gauge used to drop a little to the left. When I had my OBD plugged in this used to mark like 85C (185 F), but now on my first drive after the change, the needed remained stable in the middle with or without the radiator fan on. Unfortunately now my OBDII is not connecting to my phone for some reason, so I cannot check.

Is this normal, or is there something wrong? I was thinking maybe the new thermostat spring is still hard? or maybe there is some air trapped in the radiator, even though I tried to burp it as much as I could.

 

[TexasBlownV8]

Dont pay too much attention to the gauge; it's not perfectly linear. When you get your OBDII back working, check/monitor temps that way if you want to be more pecise.
Did you keep the same temp sensor with the new housing, or did you replace it too? Could be a factor as well.
Also, keep an eye on the fluid to make sure any air is worked out. Probably not an issue, but could be a factor, too.

 

[Max70]

I changed the housing with thermostat and sensor, I still have the old ones, so I can still replace them (not the aluminum housing) but I would have to take out the throttle body again.

When I disassembled the plastic thermostat housing, I took out the thermostat, which was still practically new and on it I found punched 92C (197F ), though I do not know about the thermostat in teh new housing. Maybe you know something about it? model I used SKP SKRH144D

The fluid I checked several times and I also topped it a little more after my first run, the OBD II I guess I need to get a new one, maybe its old and not compatible with the new BT version.

 

[Max70]

Dont pay too much attention to the gauge; it's not perfectly linear. When you get your OBDII back working, check/monitor temps that way if you want to be more pecise.
Did you keep the same temp sensor with the new housing, or did you replace it too? Could be a factor as well.
Also, keep an eye on the fluid to make sure any air is worked out. Probably not an issue, but could be a factor, too.

Today I connected my OBD2 and monitored the temperature better.

After driving for 2 hours, I found out the following
* without fan, AC or heater ON, the temperature goes up to 93/94C (201F) and the radiator fan comes on and drops it down to 90C (194F)
*with AC on, the radiator fan comes on and the temperature remains stable at 89C (192F)
*with heater on, the radiator fan comes on and the temperature drops further and remains at 88C (190F)

At this point I do not kn ow if with the coolant topping 201F before opening the thermostat (fans kicks on) is good for the engine.

 

[TexasBlownV8]

That doesn't hurt at all. 192 is the stock thermostat range, so coolant temp will often be around/over 200. Not a big deal. When it gets too hot, in the 220's at some point, the high speed will kick on, and if the a/c is running, the PCM will command it off to help cool down the engine.
It's when temps are consistently above 230 (and higher) where things can be dangerous for these engines.
Also, under pressure, the coolant/water will not boil at these temps, even with boiling point of water at 212*. Combination of antifreeze and a pressurized system when running, that raises the boiling point.
Looks like you're good to go!

 

[Max70]

Thanks for the info.

After a 3 hour drive, I went into the garage and opened the coolant reservoir's cap, also to check if there were still any air pockets left, but the coolant did not boil or bubble up, it just released some air and the coolant inside the reservoir was not hot, just warm.

 

[Dino Dino Bambino]

Today I connected my OBD2 and monitored the temperature better.

After driving for 2 hours, I found out the following
* without fan, AC or heater ON, the temperature goes up to 93/94C (201F) and the radiator fan comes on and drops it down to 90C (194F)
*with AC on, the radiator fan comes on and the temperature remains stable at 89C (192F)
*with heater on, the radiator fan comes on and the temperature drops further and remains at 88C (190F)

At this point I do not know if with the coolant topping 201F before opening the thermostat (fans kicks on) is good for the engine.

You're golden!
A temp. range of ~190-205*F (88-96*C) is where the engine runs most efficiently for good fuel economy, and is the best compromise for minimizing hydrocarbon and NOx emissions.

 

[Afolly]

You’ve made some significant changes and it’s alright that you’re paying close attention to the effects but just try to pay more attention to the Thermostat behavior and Coolant & Air pockets