Impala Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
173 Posts
Discussion Starter #1
Sooooo, my 2012 LTZ has started doing something really weird. I'll get this warning in the info display saying the engine is running hot, the A/C is deactivated and the cooling fans are turned on to help cool things down, BUUUUUUT the temperature gauge stops registering any kind of reading. The fans will continue to run after I turn the car off.

I'm thinking there's no way the car is overheating since I don't smell boiling coolant or hear any faint pinging sounds when an engine does overheat. I decide to monitor the car with my phone to see what the PCM readings are saying. Sure enough, the coolant temperature is fine with a temperature just over 150 degrees. I disconnected the battery and everything goes back to normal after I restore power. My car has done this twice now... once last Friday and once the Friday before last. How's THAT for total weirdness? Any of you guys ever have this happen?

20200425_040850.jpg Screenshot_20200425-041151.jpg
 

·
Registered
Joined
·
36 Posts
How long do the fans run after you shut down ? 150 degrees is not correct either. The engine shot be running at least 190 degrees . Fans will run after the car is off for a while as this is normal.
 

·
Registered
Joined
·
633 Posts
I've only seen that happen if the coolant level is low. I would suggest checking the coolant level, fill if necessary. If it is low, inspect for leaks. It's very common for the water pump to leak on the 3.6L engines.

Sent from my Pixel 3 XL using Tapatalk
 

·
Registered
Joined
·
173 Posts
Discussion Starter #4 (Edited)
How long do the fans run after you shut down ? 150 degrees is not correct either. The engine shot be running at least 190 degrees . Fans will run after the car is off for a while as this is normal.
Pretty sure that temperature was accurate considering that was around 4 in the morning, the outside temperature was around 45 degrees and I had just recently hit the road. The fans would run for maybe 5 - 10 minutes after the car was shut off.
 

·
Registered
Joined
·
173 Posts
Discussion Starter #5
I've only seen that happen if the coolant level is low. I would suggest checking the coolant level, fill if necessary. If it is low, inspect for leaks. It's very common for the water pump to leak on the 3.6L engines.

Sent from my Pixel 3 XL using Tapatalk
The coolant level is fine. The problem hasn't happened at all this week.
 

·
Registered
Joined
·
36 Posts
The fans would run for maybe 5 - 10 minutes after the car was shut off.
That is normal i believe when it is hot and the motor is hot . The 150 degrees is wrong...Open your hood when you shut down and see if the motor seems excessively hot. You will be able to tell.
 

·
Registered
Joined
·
173 Posts
Discussion Starter #7
That is normal i believe when it is hot and the motor is hot . The 150 degrees is wrong...Open your hood when you shut down and see if the motor seems excessively hot. You will be able to tell.
I'm pretty sure you're missing the parts where I said that this happened over a week ago and the car has been running fine all this week. Did you even look at the first photo I posted?
 

·
Registered
Joined
·
8 Posts
it’s probably your thermostat brother. I just replaced mines for the same reason. thermostat was getting stuck and not returning from the engine
 

·
Registered
Joined
·
36 Posts
I'm pretty sure you're missing the parts where I said that this happened over a week ago and the car has been running fine all this week. Did you even look at the first photo I posted?
i apologize i did not see. I would say your temp sending unit (sensor) is junk. The fact that the gauge is not working is sending wrong info .
 

·
Registered
Joined
·
173 Posts
Discussion Starter #10
i apologize i did not see. I would say your temp sending unit (sensor) is junk. The fact that the gauge is not working is sending wrong info .
No, the temperature gauge is working fine. It only did that in conjunction with everything else that happened during that weird occurrence. Again... everything went back to normal once the battery was disconnected and reconnected. It was just some crazy electronic hiccup within the system.
 

·
Registered
Joined
·
36 Posts
No, the temperature gauge is working fine. It only did that in conjunction with everything else that happened during that weird occurrence. Again... everything went back to normal once the battery was disconnected and reconnected. It was just some crazy electronic hiccup within the system.

Just drive it. It will get worse before it gets better.:LOL:
 

·
Registered
Joined
·
8 Posts
No, the temperature gauge is working fine. It only did that in conjunction with everything else that happened during that weird occurrence. Again... everything went back to normal once the battery was disconnected and reconnected. It was just some crazy electronic hiccup within the system.
If it happens intermittently (like mines did) it’s the thermostat. I paid my mechanic 60bucks to replace and haven’t had that problem since
 

·
Registered
Joined
·
1 Posts
It is the plug on the temp sensor.
Put some dialectric grease in it. Should solve your problem.
Has nothing to do with the stat when it is intermittent like that.
 

·
Registered
Joined
·
173 Posts
Discussion Starter #14
Just an update. It's been over two months since I've started this thread. I haven't repaired anything and the problem hasn't returned. Again... I'm positive it was just an electrical hiccup.
 
1 - 14 of 14 Posts
Top