The Practicality of Thermal Imaging

Mario from Weston Diagnostician Posted   Latest   Edited  

Wouldn't it be great if there was a page where we can see the many functions and benefits of using a thermal imaging through our diagnostic journeys? Well why not start right here, right now? And who better to start it with than with the amazing, sharp technicians in our day and age?

This is an open invitation for all to post their thermal images. It'd also be nice to describe the objective or diagnosis of your image, followed by the thermal image(s) itself. Optional enlightenment is also welcome.

I'll start things off!

Here's a battery with excessive resistance at the negative terminal, easily over 150 degrees!

Here's a partially clogged heater core!

This one here is for demonstration purposes, to show the effect emmisivity has on the accuracy of a thermal image. It will also serve to start a discussion on emmisivity, one of the most misunderstood, disregarded aspects of Thermal Imaging. 

I hope we can all benefit from the thermal images that are to follow, maybe even collect enough to form a library of sorts. Who knows? At this point, anything goes


Cliff from Santa Maria



Here’s one of a battery...This was after the battery had been sitting out of the vehicle l for over an hour.


Michael from Clinton


Mobile Technician

Cool Stuff! I will need to take my imager out tomorrow and take some pictures.


Jim from Frederick


Curriculum Developer

Good start here. One of the things I always keep in mind is that in a simplistic way, these cameras are multi point infrared guns. The same things that can give inaccurate results with those temp guns can skew what the camera records. Reflective surfaces bounce radiated heat. Black or flat colors will tend to be more accurate readings. To make the point, here is a "selfie" taken in front of a Stainless Steel refrigerator.........


Jim from Frederick


Curriculum Developer

Scott Brown, I told you I had a good profile picture to upload.........

I think my hazel eyes really pop in this picture......


Pete from Zephyrhills



I produced a video on this very topic back in August. Hope it helps!



Chris from Bryans Road



Here is one I took after I fixed a seat heater in a Mercedes a while back. Fun topic Mario



Matthew from Lawrence



Great topic Mario! I love my thermal imager. Here are a couple shots of a bad hybrid battery in a Gen2 Prius. I captured these by tearing the interior out, taking the vehicle on a "hard" test drive and then removing the battery cover. This is usually not necessary as the Toyotas typically will set a code for the failed battery module.

As far as emmisivity, it's super important to get the setting right. Until i changed the setting on my thermal imager for plastic these images appeared all the same color. The Snap-On unit makes the setting pretty easy.


Jacques from Devon



Thermal imaging made quick work of finding out which circuit was staying awake and draining the battery.


Ryan from Edmonton



Here is an Espar engine heater with a failed water pump. The unit would fire up and overheat due to lack of flow.

The other one was from a Peterbilt that would need to be boosted every day. It would be left to run for a couple of hours. Then the connections and batteries would be tested. Everything checked out fine. I finally get it, and it was the same story. Clean connections, good voltage drops, and all four batteries would pass the load test. I let it sit for a couple of hours...and look what I found. The warm battery would discharge the other three in a day. It went from 760 CCA on that one to 276 CCA in couple of hours.


Tom from Santaquin



here is a bat. pic bad cells and on some i can see the water level. 

and with heater blower connectors under dash power and grounds separate connectors it wood work intermittent.


Ward from Saskatoon



Here's a noisy serpentine belt idler pulley, and what an Aim-9 Sidewinder sees.



Bob from East Longmeadow



Rear window defogger

Heated side view mirror

Brake rotor Good Brake rotor Bad

Battery post resistance


Eric from Edgerton



Here is a thermal image from a car with a restricted heater core.

And here's the image after the core was back flushed.

Here is a faulty circuit breaker used for an electric radiator fan. The fan ran noticeably slower than the other one mounted next to it that had it's own circuit breaker.

Here you can see the heat generated by a drum brake system. You can even see that the larger trailing shoe does actually do more work since it is hotter than the smaller leading shoe.

And a set of four images after a brake repair test drive.