06/18/2026
🍁 Sometimes the answer isn't in a scan tool... it's in the process.
One of the biggest misconceptions about modern vehicle diagnostics is that we simply plug in a scan tool, the computer tells us what's wrong, and we replace a part.
If only it were that simple.
This screenshot is from an oscilloscope connected to a vehicle with a gradual coolant loss concern. Along with scan data, we've performed cooling system pressure testing, a combustion gas (block) test, borescope inspections, reviewed service information, and even consulted with technicians who have extensive experience with this particular engine platform.
Every test gives us another piece of the puzzle.
Sometimes a test rules something out.
Sometimes it points us toward the next question.
Sometimes it completely changes the direction of the diagnosis.
The goal isn't to replace parts until the problem disappears. The goal is to understand why the problem exists before recommending a repair.
This particular vehicle still isn't conclusively diagnosed, and that's okay. Good diagnostics means being honest about what you know, what you don't know, and continuing to follow the evidence instead of making assumptions.
Testing over guessing isn't always the fastest path, but it's the path that gives our customers the best chance of getting the right repair the first time.
🍁 The Canuck Mechanic
Testing over guessing.
