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.