[warriordave927]

Ok guys so before anything I've already read previous threads about the issue relating to the problem I am having with the car my question will be more about the dealers reaction and advice given by them.

So to begin a couple of days ago when I got home my fan stayed on after shutting the car off and took about 5 minutes to go off. I went back and checked the coolant temp and temp reading was blank and temp gauge was all the way to the cold side. So I assumed temp sensor checked here and seemed a common issue,took it in to the dealer the next day and by this point I noticed the ac wasnt cooling either. They plugged in a scanner and showed a p0128 code even though the cel never came on. The advisor tells me with that code more than likely the thermostat,they would have to keep the car or he said I could take it home and bring it back on monday. I told him this is my only form of transportation but being that the thermostat is bad would it not be a bad decision to drive it seeing as the temp gauge isnt reading. Now I know the thermostat can go either way either stay in the closed or open position. My concern is if the thermostat is stuck closed and I am not getting a temp reading the car overheating and causing further damage. I chose to leave the car at that point hoping they would have it ready today. The advisor called to let me know the thermostat was out of stock and would have to be ordered,they wouldnt have it until monday. So again he tells me I can come pick the car up and drop it off on monday. Twice now theyve told me to drive the car home without concern even though according to them they know the issue is the thermostat. To get to my point is this negligence on their part to not be concerned about possibly overheating the car or am I just being paranoid. They did not offer me a loaner even though I specified this was my sole means of transportation only offering their shuttle service. I do need the car to run errands and get to work this weekend so I would like to pick it up and use until monday but am afraid of damaging the car further if it happens to overheat. Any advice from people that have experienced this issue or if anyone is more familiar with the workings of the camaros cooling system. Thanks in advanced

[Jeb114]

Thermostats are designed to fail in the open position as not to overheat the vehicle. Been this way since the 70's...

[Scottyz]

I’ve seen them fail both ways actually. Both on vehicles and heavy equipment.
I’m surprised there is no reading on your gauge. Like are you sure it’s not building any heat ???
Was there coolant in the system to begin with?

[Soleil]

Are you 100% sure that the thermostat is defect? My fan runs also sometimes after switching off.
When you go back on Monday let them check the code again. I wouldn’t be surprised if nothing comes up.

[ctrlz]

I think your coolant temperature sensor is faulty. Everything else could just be secondary to that problem.
The car is not going to behave right without the coolant temp info. Knowing that value is a precondition for a lot of subsystems.

[warriordave927]

Dont know if it's the thermostat or not just going by what the advisor is telling me. I ended up picking up the car today and was surprised to see that the temp gauge was reading again and the ac started working properly. I'm not sure if they disconnected the battery or reset it somehow but itll still be going in on monday so they can replace the thermostat.

[ctrlz]

Originally Posted by warriordave927

going in on monday so they can replace the thermostat.

Now that your temp gauge is working you can see how the thermostat is behaving. Basically it should rise to about 200 deg F and stay pegged there (the actual normal position for your car may vary within a few degrees of 200). If your thermostat is stuck closed (or close to closed) the temperature will climb above 200, particularly at lower speeds like when you are stuck in traffic. If it is stuck open, temperature will drop below 200 at higher speeds (highway driving). If the 'stat is sticking intermittently, the temp will bounce around occasionally.
The above are the reasons to replace a thermostat. Unless the coolant temp sensor is part of the thermostat assembly (pretty sure it is not on this car), I can see no reason to replace the thermostat. OTOH, if your temp gauge was not reading and now it is working again, I would interpret that as intermittent failure of the temp sensor and replace that, usually a $10 part and (comparatively) not hard to access. Thermostats these days are often buried behind other assemblies and a PITA to replace.


Based on what you have reported, I think your dealer may not know how to approach this problem.

[jwober]

FYI P0128 is typically thought to be a bad thermostat because the code is stored when the engine coolant temperature doesn't reach a set temperature in a set time. Typically 160 degrees F in 15 minutes. As stated above a defective CTS (coolant temp sensor) could also be possible and would be in line with a blank temp display, but much rarer.

[crosive]

Originally Posted by Jeb114

Thermostats are designed to fail in the open position as not to overheat the vehicle. Been this way since the 70's...

be that as it may, I've never replaced a thermostat (and I have replaced several) that was stuck open. The ones I've replaced, I replaced because they never opened, causing overheating.

[ctrlz]

Originally Posted by crosive

The ones I've replaced, I replaced because they never opened, causing overheating.

I've replaced them stuck open, closed, and sticking intermittently.
I've never had a thermostat problem cause the gauge to not respond. That is invariably a sensor or gauge problem.
The stuck open thermostats usually present with complaints of heat not working, as most people pay zero attention to any gauge other than fuel.

[Xyebo]

I've had the same problem on my V6 Camaro: the coolant gauge was planted at nil and the digital coolant temp readout was "--" instead of a numerical temperature; the radiator fan would run full-blast when the car was on, and it would run at ~50% speed for 10 minutes after shutting down the engine.


Took it into the dealership, and the techs replaced the thermostat housing assembly; now the issue is gone.

[Viessman09]

Originally Posted by Xyebo

I've had the same problem on my V6 Camaro: the coolant gauge was planted at nil and the digital coolant temp readout was "--" instead of a numerical temperature; the radiator fan would run full-blast when the car was on, and it would run at ~50% speed for 10 minutes after shutting down the engine.


Took it into the dealership, and the techs replaced the thermostat housing assembly; now the issue is gone.

How expansive was this work? Mine wants to charge me 1100.

[s346k]

Originally Posted by Viessman09

How expansive was this work? Mine wants to charge me 1100.

$1100 to change the thermostat housing? wtf.

i circled it in that picture. 3 bolts and 2 hoses. might be a 20 minute project.

[GTIanZ28]

Originally Posted by s346k

$1100 to change the thermostat housing? wtf.

i circled it in that picture. 3 bolts and 2 hoses. might be a 20 minute project.

I’ve been trying to replace my thermostat on the LGX for 3 days now. I should have taken a picture.

In order to get to the thermostat on the LGX you have to remove the entire intake system to include the intake manifold. The thermostat is in between the heads in the valley. This is where the problems begin. There is a metal return line coming off of the block that is directly above one of the thermostat bolts. There is zero room to get a wrench or socket to the bolt. I’ve bought every tool I could find that might work.

I’m at a complete loss at this point about what I should do (besides taking it to the mechanics).