A trick for finding vacuum leaks that actually worked for me

I had a 2008 Civic with a rough idle that was driving me nuts for about two weeks. I tried the usual carb cleaner spray around the intake, but it wasn't showing anything. On a whim, I grabbed a can of starting fluid and sprayed it very lightly along the vacuum lines. The idle smoothed out for a second when I hit a cracked line behind the throttle body that I couldn't even see. Fixed it with a 3 inch piece of hose I had in my box. Anyone have a different method for tracking down those tiny leaks?

3 comments

3 Comments

felixfisher1mo ago

Honestly always thought starting fluid was too risky for that kind of thing... worried about a flash fire or something. Your post made me try it on my old truck last weekend though, just being super careful. Found a pinhole in a line to the brake booster I never would have spotted. Might be my go-to method now for those sneaky leaks.

pat_schmidt6029d ago

Hah! Talk about playing with fire, literally. I've got to hand it to the guys who try starting fluid though - it's like using a flamethrower to find a mosquito. I tried the old hose-to-the-ear trick on my buddy's Subaru once and ended up looking like a total idiot holding a garden hose to my head while the engine was running. Neighbors probably thought I was trying to commune with the car. At least with the starting fluid method you might end up with a cool story about a small fire instead of just looking foolish.

johnson.daniel1mo ago

Worry about that method causing more problems than it solves honestly. Starting fluid is crazy flammable and you're spraying it near hot engine parts and electrical connections. Seen a small engine fire start from less. There are safer ways like using a smoke machine or even just listening closely with a hose to your ear. That quick fix just isn't worth the real risk of burning your car down.