Update: That day a customer's old truck taught me about vacuum leaks

Had a 1987 Ford F-150 come in with a rough idle that three other shops couldn't fix. I spent maybe an hour just listening with a piece of heater hose, and found a tiny crack in a vacuum line behind the intake that sounded like a hissing snake. Anyone else have a go-to method for tracking down those sneaky vacuum leaks on older engines?

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3 Comments

willowadams6mo ago

Man, that hose trick is a classic for a reason. Honestly, I've had decent luck with a cheap cigar and watching where the smoke gets sucked in on a cold engine. It sounds dumb, but it finds those invisible leaks nothing else can. Old school fixes for old school problems.

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adam5176mo ago

Honestly I've seen that smoke trick do more harm than good, gumming up sensors and hoses.

4

derekl796mo ago

My buddy swears by spraying carb cleaner around the hoses, his old Chevy would rev up and point right to the leak lol.

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