Had a 2008 Civic with a weird idle that took me forever to track down

Honestly, it was just a rough idle that would come and go. I checked the usual stuff, plugs, coils, cleaned the throttle body, nothing. Tbh, I spent about four hours on it before I found the real problem. It was a tiny crack in the intake hose after the MAF sensor, only visible when the engine was hot and the hose flexed. Ngl, I felt pretty dumb for missing it. Has anyone else had a simple vacuum leak hide like that on a Honda?

2 comments

2 Comments

rosejackson1d ago

Those tiny cracks are the worst, they never show up on a cold engine. A cheap trick is to spray some carb cleaner around the hoses while it's running and listen for the idle to jump. Saves a ton of time hunting for leaks.

viola_cooper6222h ago

Carb cleaner works but it can eat through some rubber hoses over time. The old school guys at the auto parts store always told me to use a water spray bottle instead. If there's a vacuum leak, the idle will smooth out for a second when the water seals the tiny crack. It's a lot safer for the engine bay plastics too.