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The engine bay is super hot even when the outside temps are 40 to 60 degrees. It does not seem like much air gets inside the engine bay, there is that huge cover under the engine that seals off all the air. Have you noticed any heat soak yet? Our super-hot weather is not even here yet, soon we will have temps 104 to 110, and it's even hotter on the road, maybe 125 or so. You probably get even hotter than Boise.
Actually, haven't noticed heat soak....
I am pretty sure I know why they sealed off the engine bay like they did: hydrolock.....
But that doesn't seem to be a good enough reason to seal off the bay and let heat damage everything.....
The unloaded battery voltage should range around 12.2V to 12.6 at room temperature (25C), with the engine off. The internal battery resistance & resultant voltage drop due to the charging current is the reason for the static & charging voltage at the battery terminals are different. With the engine on and alternator charging, the voltage at the battery terminals should be about 13.8V to 14.7V at 25C. The actual voltages are temperature dependent.
You can monitor this with VCDS (and maybe OBDeleven).
Module 19-CAN gateway > Measuring Blocks > Groups 18,19 and 20
Here an example of the VCDS monitor battery status with engine NOT running (static):
Here an example of the VCDS monitor battery status with engine Running (charging):
So - during my "issue", I've measured 13.0v's at the battery terminals (both sets) while the engine is on....
My battery with the engine off is 12.6v's and is stable.
While running this evening, input voltage to all of my accessories dropped to 11.8v's (Radar Detector, OBD port, Blackvue backup batteries, etc.).
I didn't know, but will try to monitor with OBD11 (I have VCDS, but I am physically unable to get it all hooked up and monitor it, while driving....
The one thing I've forgotten to note about this: The voltage drops ONLY occur after the car has reached running temps and oil temps ~200d's+.
This is why I'm concerned it might be the alternator, a harness, battery control module, or the battery itself.
The temperature issue HAS to be a factor.
My trunk, itself, where the spare is, I have measured 140d (my remote start temp sensor and another sensor in a backup battery).
I don't know WHAT is getting so hot in there, but I cannot even touch the 360d camera control module after even a 10 minute drive.
Again, no codes.....
Originally Posted by m444
The unloaded battery voltage should range around 12.2V to 12.6 at room temperature (25C), with the engine off. The internal battery resistance & resultant voltage drop due to the charging current is the reason for the static & charging voltage at the battery terminals are different. With the engine on and alternator charging, the voltage at the battery terminals should be about 13.8V to 14.7V at 25C. The actual voltages are temperature dependent.
You can monitor this with VCDS (and maybe OBDeleven).
Module 19-CAN gateway > Measuring Blocks > Groups 18,19 and 20
Here an example of the VCDS monitor battery status with engine NOT running (static):
Here an example of the VCDS monitor battery status with engine Running (charging):
07-06-2020, 02:49 PM
