Watching A Frozen Engine Warm Up With A Thermal Camera


Hello everyone, and welcome! In this video, we’re going to be cold-starting
the engine of my 2016 Subaru Crosstrek and, using a thermal camera, we’re
going to watch the engine heat up. Now, to be perfectly honest,
I am making this mostly out of curiosity, just to see what it looks like
when an engine warms up. But I thought I’d also take the time to address some
questions relating to my video on whether or not you should warm up your engine before driving off. Now, I do have to apologize for
the resolution of the thermal camera. It’s obviously not nearly as crisp as my 4K camera,
but, nonetheless, it’s a valuable tool for learning. The ambient temperature is about -6°C, or about 22°F,
and my engine hasn’t run in the past 24 hours. As far as metrics we’ll be monitoring, we’ve got overlays of the engine RPM,
which will run higher when the engine first starts to help warm things up. We also have throttle position,
the coolant and intake air temperatures, the temperature of where the
thermal camera is centered, and the timestamps so we know
how long the engine has been running. Back on the subject of warming up your engine, in my previous video, which I’d certainly recommend
watching for more detail on the subject, I recommended only a brief duration
of warming up your engine, anywhere from 15 to 30 seconds
if it’s fairly cold outside, and then lightly driving your car until all of the
necessary components get to operating temperature. Let’s start with the obvious. If it’s freezing outside and you
don’t want to get in a frozen car, no one is going to fault you for warming up the
engine and making sure it’s comfortable inside, as well as making sure the windows
are defrosted, so your’e ready to roll. In my video, I was purely discussing what’s
happening from a mechanical standpoint when you let your engine sit in idle. Some information certainly worth knowing, though, is
that oil can actually flow at very low temperatures. You may be freezing, but for certain viscosity
grades, cold temperatures aren’t a huge deal. For example, my Honda S2000
recommends a 10W-30 oil and it only recommends going down to a thinner, 5W
grade oil if ambient temperature drops below -20°C. -20°C! And this is logical based on SAE
cold temperature viscosity ratings. For example, a 0W oil needs
to be able to pump at -40°C. A 5W oil needs to be able to pump at -35°C. A 10W oil needs to be able to flow at -30°C and so on… Oil can do a decent job of protecting
your engine, even at low temperatures, as long as you’re not asking the
engine for too much power. Try to keep the revs low, and be light on
the throttle until the engine is warmed up. Getting to higher vehicle speeds is fine,
as long as your acceleration is gentle and steady and you’re mindful of your engine RPM. Now, inevitably, someone in the comments is
going to say they live in an area with -40°C temps, and they always warm their car up
for several minutes before taking off. A couple of things to note here: First, that’s obviously super cold and I can’t
blame you for wanting the interior to be warm. Second, make sure you’re using a viscosity
grade that can flow in these conditions; 0W is designed for this. Third, with temperatures this low,
it’s a good idea to get an electric engine block heater, so your engine would have to strain
so hard to get oil flowing throughout. And, finally, point #4: move to Florida. It’s warm and sunny and you don’t have to
worry about your face muscles freezing in place. Now we’ll do a bit of a time-lapse and
watch the engine continue to heat up. At about 5 minutes and 20 seconds,
when the coolant temperature reaches 50°C, you’ll notice the engine RPM starts to significantly drop. Eventually getting down to 800 RPM
when the coolant reaches 60°C. At 7 minutes after starting,
we’re looking at the engine oil filter. Obviously not yet to operating temperature,
but at about 36°C, or about 100°F. Next we’re looking at the coolant lines,
heading to the heater core for warming up the cabin. These are at about 50°C, or 120°F. Looking at the radiator hose, it’s about 33°C, or 90°F. Looking at the intake mainfold, it’s at about 6°C, or 43°F, and that’s consistent with what the
OBD 2 readout is getting at 3°C. The outside air is at -6°C but warms
up as it enters the engine bay. Looking at the alternator, you can see various
sections ranging from about 12°C-20°C. And, finally, looking at the battery—
still pretty much completely frozen. So, hopefully, this has been
both interesting and insightful. I will be sure to include a link to the thermal
camera used in the video description. If you have any questions or comments,
feel free to leave them below. Thanks for watching.