What does your engine look like on the inside as it warms up? Aside from some "Honey I shrunk the kids" scenario in which you could protect yourself from heat and the mechanical bits inside your engine, finding out seems impossible, doesn't it? Not with a thermal camera.
Out of curiosity, Jason Fenske from Engineering Explained decided to look at the engine of his 2016 Subaru Crosstrek through a thermal camera. Of course, the video he shot is more than just a curiosity. He uses it to show us what's going inside an engine as it warms up.
The engine in question hasn't been run for about 24 hours and the temperature is about 22 degrees Fahrenheit, making this a genuinely cold start. To keep track of things, Jason overlays the video with the engine revs, throttle position, coolant and intake air temperatures, the temperature of where the thermal camera is centered, and a timestamp to keep track of how long the engine has been running.
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So what do we learn? First of all, Jason notes that oil can flow at very low temperatures. That's because most oils have a low-temperature viscosity rating. That's the 10 in the 10W 30. Jason suggests keeping the revs low and going light on the throttle until the engine is warmed up.
After about five minutes of running, we can see that the coolant temperature reaches 50 degrees Celcius (122 F) and the engine rpms start to drop. When the coolant reaches 60 C, or 140 F, the revs fall all the way to 800 rpm.
Jason goes on to take a look at various components of the engine and measure the relative temperatures. He finds varying temperatures for the components, and the mechanical geeks among us will find that information interesting. Watch the video to find out the difference between the oil filter and intake manifold temps, for instance, or to see how the alternator has different temperatures in different areas.