MBP water damage diagnosis

Question

I accidentally spilled water on to my 2017 MacBook Pro (Touch bar) (keyboard and trackpad), and because I panicked a bit I used the immediate reboot key (shift+control+option+command+power) instead of holding the power key for a few second, which delayed the time until complete power off for about 15 seconds (because the MBP restarted and I didn't notice that until the power chime). In total, the MBP was exposed to water for around 30 seconds while powered on. After this incident, I left my MBP in a reverse position for around 3 days. Then I checked whether the machine will turn on, and after the screen turned on I turned it off immediately. I noticed that the fans are turned on at maximum speed. Afraid that there are still water left, I left the MBP for another 2 weeks. The MBP passed HDT two times, and booted up normally. However, there are occasional halts when I'm greeted with the login window and when I log in. After I logged in, everything worked normally.

What is the possibility that water permanently damaged my MBP and it will stop working soon? What is the possibility that there are still water left in there? If I use it normally, will there be more damage? In the worst case, can I still recover my data?

The main suspects I have so far is extremely slow login (including command-line login for Terminal), and abnormal sensor data. istats scan:

Scanning keys...

TaLC Unknown:           29.69°C     ▁▂▃▅▆▇
TaRC Unknown:           29.06°C     ▁▂▃▅▆▇
Th1H NB/CPU/GPU HeatPipe 1 Proximity: 33.31°C     ▁▂▃▅▆▇
Th2H Unknown:           29.88°C     ▁▂▃▅▆▇
Ts0P Palm rest L:       27.31°C     ▁▂▃▅▆▇
Ts0S Memory Bank Proximity: 28.98°C     ▁▂▃▅▆▇
Ts1P Unknown:           26.25°C     ▁▂▃▅▆▇
Ts1S Unknown:           31.34°C     ▁▂▃▅▆▇
TA0V Unknown:           28.7°C      ▁▂▃▅▆▇
TBXT Unknown:           30.3°C      ▁▂▃▅▆▇
TB0T Battery TS_MAX:    30.3°C      ▁▂▃▅▆▇
TB1T Battery 1:         29.0°C      ▁▂▃▅▆▇
TB2T Battery 2:         30.3°C      ▁▂▃▅▆▇
TCGC PECI GPU:          38.0°C      ▁▂▃▅▆▇
TCMX Unknown:           39.0°C      ▁▂▃▅▆▇
TCSA PECI SA:           37.0°C      ▁▂▃▅▆▇
TCTD Unknown:           -1.02°C     ▁▂▃▅▆▇
TCXC PECI CPU:          39.97°C     ▁▂▃▅▆▇
TC0E CPU 0 ??:          42.0°C      ▁▂▃▅▆▇
TC0F CPU 0 ??:          43.69°C     ▁▂▃▅▆▇
TC0P CPU 0 Proximity:   34.69°C     ▁▂▃▅▆▇
TC1C Core 1:            40.0°C      ▁▂▃▅▆▇
TC2C Core 2:            40.0°C      ▁▂▃▅▆▇
TH0a Unknown:           27.94°C     ▁▂▃▅▆▇
TH0b Unknown:           -1.02°C     ▁▂▃▅▆▇
TH0c Unknown:           -1.02°C     ▁▂▃▅▆▇
TH0x Unknown:           -127.0°C    ▁▂▃▅▆▇
TH0A Unknown:           27.94°C     ▁▂▃▅▆▇
TH0B Unknown:           -1.02°C     ▁▂▃▅▆▇
TH0C Unknown:           -1.02°C     ▁▂▃▅▆▇
TH0F Unknown:           -52.06°C    ▁▂▃▅▆▇
TH0R Unknown:           -52.06°C    ▁▂▃▅▆▇
TM0P Memory Slot Proximity: 33.75°C     ▁▂▃▅▆▇
TPCD Platform Controller Hub Die: 37.0°C      ▁▂▃▅▆▇
TSDV Unknown:           -127.0°C    ▁▂▃▅▆▇
TTLD Unknown:           29.44°C     ▁▂▃▅▆▇
TTRD Unknown:           27.5°C      ▁▂▃▅▆▇
TW0P AirPort Proximity: -127.0°C    ▁▂▃▅▆▇

Done scanning keys.
All keys are disabled by default. Use `istats enable [key]` to enable specific keys or `istats enable all`.
The enabled sensors will show up when running `istats` or `istats extra`.

istats extra on 15-inch 2017 MBP:

Scanning keys...

TaLC Unknown:           32.0°C      ▁▂▃▅▆▇
TaRC Unknown:           43.44°C     ▁▂▃▅▆▇
Th1H NB/CPU/GPU HeatPipe 1 Proximity: 46.63°C     ▁▂▃▅▆▇
Th2H Unknown:           49.38°C     ▁▂▃▅▆▇
Ts0P Palm rest L:       29.94°C     ▁▂▃▅▆▇
Ts0S Memory Bank Proximity: 38.13°C     ▁▂▃▅▆▇
Ts1P Unknown:           29.31°C     ▁▂▃▅▆▇
Ts1S Unknown:           35.63°C     ▁▂▃▅▆▇
Ts2S Unknown:           37.28°C     ▁▂▃▅▆▇
TA0V Unknown:           27.97°C     ▁▂▃▅▆▇
TBXT Unknown:           34.39°C     ▁▂▃▅▆▇
TB0T Battery TS_MAX:    34.39°C     ▁▂▃▅▆▇
TB1T Battery 1:         32.0°C      ▁▂▃▅▆▇
TB2T Battery 2:         34.39°C     ▁▂▃▅▆▇
TCGC PECI GPU:          62.0°C      ▁▂▃▅▆▇
TCMc Unknown:           -128.0°C    ▁▂▃▅▆▇
TCSA PECI SA:           68.0°C      ▁▂▃▅▆▇
TCTD Unknown:           -1.09°C     ▁▂▃▅▆▇
TCXC PECI CPU:          69.22°C     ▁▂▃▅▆▇
TC0E CPU 0 ??:          71.94°C     ▁▂▃▅▆▇
TC0F CPU 0 ??:          73.89°C     ▁▂▃▅▆▇
TC0P CPU 0 Proximity:   52.88°C     ▁▂▃▅▆▇
TC1C Core 1:            69.0°C      ▁▂▃▅▆▇
TC2C Core 2:            68.0°C      ▁▂▃▅▆▇
TC3C Core 3:            63.0°C      ▁▂▃▅▆▇
TC4C Core 4:            66.0°C      ▁▂▃▅▆▇
TGDD Unknown:           51.0°C      ▁▂▃▅▆▇
TGVP Unknown:           47.0°C      ▁▂▃▅▆▇
TG0D GPU 0 Die:         56.31°C     ▁▂▃▅▆▇
TG0F Unknown:           53.91°C     ▁▂▃▅▆▇
TG0P GPU 0 Proximity:   50.5°C      ▁▂▃▅▆▇
TH0a Unknown:           43.0°C      ▁▂▃▅▆▇
TH0b Unknown:           38.5°C      ▁▂▃▅▆▇
TH0c Unknown:           41.88°C     ▁▂▃▅▆▇
TH0x Unknown:           -127.0°C    ▁▂▃▅▆▇
TH0A Unknown:           43.0°C      ▁▂▃▅▆▇
TH0B Unknown:           38.5°C      ▁▂▃▅▆▇
TH0C Unknown:           41.88°C     ▁▂▃▅▆▇
TH0F Unknown:           -35.19°C    ▁▂▃▅▆▇
TH0R Unknown:           -35.13°C    ▁▂▃▅▆▇
TM0P Memory Slot Proximity: 46.56°C     ▁▂▃▅▆▇
TPCD Platform Controller Hub Die: 37.0°C      ▁▂▃▅▆▇
TTLD Unknown:           33.19°C     ▁▂▃▅▆▇
TTRD Unknown:           48.06°C     ▁▂▃▅▆▇
TW0P AirPort Proximity: 47.25°C     ▁▂▃▅▆▇

Done scanning keys.
All keys are disabled by default. Use `istats enable [key]` to enable specific keys or `istats enable all`.
The enabled sensors will show up when running `istats` or `istats extra`.

Answer 1

We've had four spills over Mac laptops in the family, so I've had a fair bit of experience.

It is impossible for someone to say with any degree of certainty how long your Mac will last. Water spill damage is 'not good', but the effects can vary depending on what part got wet, for how long, whether it was powered, etc, etc, etc.

However, I would not expect the machine to last as long as a 'dry' Mac, nor would I rely on it.

There are two main issues: one is electrical shorting, where current travels across the water, damaging the components. This usually happens instantly. The extent of damage and the importance of the component can vary: a problem with a sensor could well be a result of this.

If sufficient damage has occurred, then the Mac can be completely lifeless.

The other is corrosion from salts in the water that are left behind after the water has evaporated. This is a more long-term issue, and may cause increasing problems with use and time.

In short: after water damage, you should take the Mac in to an Apple Repair shop for investigation.

"In the worst case, can I still recover my data?"

In 2007, Apple introduced Time Machine as a feature in OS X Leopard. Every file that you want to keep should be on one or more backup copies. This website bears testimony to frequent accidental deletions, catastrophic hardware failures, thefts, fires, etc, etc.

If you do not have a backup, you should try to get your files off the laptop onto one (or more) external drive as soon as possible while it still works. Your Mac has its storage soldered directly on to the logic board, so data recovery will be expensive.