Why does nobody talk about using a cheap infrared thermometer to find a dead cylinder before pulling injectors

Mason Gibson · 2026-05-08T17:25:05.409933+00:00

Saved me 3 hours last week on a Cummins ISX by finding the cold exhaust port right away, anyone else use one of these for diagnosis?

mason_foster683mo ago

Maybe it's just me but a quick multimeter check does the same thing without buying a new tool.

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charlie_allen4mo ago

Is it really that serious, or just a fancy way to check for a cold pipe?

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mason_foster684mo ago

Man, that ISX trick is gold. I've done the same thing on a few Detroit 60 series, and it saves you from chasing your tail with a multimeter on the harness first. @charlie_allen it's not just a cold pipe, you're looking for a temperature difference of 20-30 degrees on a fully warmed up engine, that's a dead giveaway for a misfire. Just be careful not to point it at anything shiny or you'll get a bad reading, aim for the manifold flange or the base of the exhaust riser.

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