coolant temps cycling *LOG*

[THE REAL DEAL]

So I noticed this a couple weeks ago but I finally made a log to show you guys. This is cruising at 60 mph in 5th.

TIMA COOL FTO2 O2-R TPS RPM INJP
27° 203.0°F 97.5% 0.74V 28.2% 2469 3.84ms
31° 203.0°F 85.8% 0.25V 27.1% 2500 3.58ms
33° 203.0°F 104.5% 0.08V 26.7% 2500 3.58ms
33° 203.0°F 114.7% 0.66V 26.7% 2500 3.33ms
33° 203.0°F 111.5% 0.18V 26.7% 2500 3.58ms
33° 203.0°F 115.4% 0.72V 26.7% 2500 3.33ms
33° 203.0°F 112.3% 0.33V 27.1% 2500 3.58ms
33° 203.0°F 115.4% 0.66V 27.8% 2500 3.58ms
33° 203.0°F 120.1% 0.60V 28.2% 2500 3.84ms
32° 203.0°F 110.8% 0.53V 28.2% 2500 3.84ms
32° 203.0°F 105.3% 0.64V 28.2% 2531 3.84ms
32° 199.6°F 113.9% 0.72V 27.8% 2531 3.84ms
32° 186.1°F 103.0% 0.43V 26.3% 2531 3.58ms
33° 203.0°F 112.3% 0.62V 25.9% 2531 3.07ms
34° 196.3°F 101.4% 0.62V 23.9% 2531 2.82ms
35° 203.0°F 106.1% 0.62V 23.5% 2500 2.56ms
35° 203.0°F 94.4% 0.72V 22.0% 2531 2.05ms
36° 203.0°F 84.2% 0.66V 21.6% 2500 2.05ms
36° 203.0°F 72.5% 0.76V 21.2% 2500 2.05ms
37° 203.0°F 48.4% 0.43V 21.2% 2500 1.79ms
37° 203.0°F 64.7% 0.21V 21.2% 2500 2.05ms
36° 203.0°F 64.7% 0.20V 25.5% 2500 2.82ms
34° 203.0°F 82.7% 0.02V 26.3% 2500 3.07ms
34° 203.0°F 99.1% 0.02V 26.3% 2469 3.33ms
33° 199.6°F 117.0% 0.06V 26.7% 2500 3.58ms
33° 203.0°F 129.5% 0.68V 27.1% 2500 3.58ms
33° 203.0°F 118.6% 0.74V 27.1% 2500 3.58ms
33° 192.9°F 107.6% 0.35V 27.1% 2500 3.58ms
33° 203.0°F 111.5% 0.72V 26.7% 2500 3.33ms
33° 203.0°F 103.7% 0.43V 25.9% 2500 3.33ms
34° 203.0°F 118.6% 0.59V 25.5% 2500 3.07ms
34° 203.0°F 108.4% 0.66V 25.1% 2500 3.07ms

Sometimes the temp will drop down from 203 to 55 at idle and at times I've seen it go all the way up to around 255. Should I replace my sensor?

 

[DSM90AWD]

I'd definitely check the connection first as it the wires at the thermostat housing get very brittle with age and will crack/corrode changing the resistance of the wire (which directly affects the value the ECU reads). If the wires are ok, go ahead and take the plug off and shoot with some contact cleaner/WD40. Dress with a dab of dieletric grease and see if it helps. If not, find a new sensor

 

[THE REAL DEAL]

replaced the sensor. problem fixed.