Left fan constantly runs full speed - no load, no overheat
My late 2013 MacBook Pro took a Coke spill right into the keyboard about a year or so ago. The machine returned to gook working order after a while (despite keys that can be somewhat sticky from time to time). Recently, however, the left fan has begun running at full speed constantly. SMCFanControl right now reports it at 6846, and this doesn't seem to fluctuate at all. The fan begins this behavior immediately after bootup, even before the Apple logo appears. This has happened once or twice in the past, but after a short while the fan returned to normal.
The system is not under any CPU load whatsoever, and this happens with the laptop on a hard and flat surface. The left fan seems to be the only one affected.
I ordered and installed a brand new left fan, just to rule out an issue with the fan itself. Same behavior - full speed ahead.
The last 3 of my serial are D59.
I would suspect that this could be related to the sensor(s) being compromised in the spill, but I don't know where to look to check them, clean them, or anything else.
Can anybody give me any pointers or next steps?