Soapy water in spray container to find leaks?

Leahatrill

Leahatrill

TJ Enthusiast
Joined
Feb 7, 2020
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Toronto
Has anyone used soapy water in a spray container to spray in the engine bay area to find leaks in the vacuums or manifold etc etc. And does it work?
 
Sometimes it works; usually not. Unlike tires pushing air out which makes bubbles, you have to look for where water is being sucked in.

Try WD40 or starting fluid - sometimes you can find a vacuum leak by listening for the change in rpm when you spray it around a running engine. However, sometimes you end up spraying stuff all over the place, waste all of it, and wind up cursing the poor sod who showed up at the Jeep assembly line with a debilitating hangover on the day your jeep was built. :oops:
 
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You would do better with cheap shaving cream probably ...you’d see voids .
 
The use of starting fluid or WD40 are good suggestions to locate a vacuum leak, but just be careful using flammable liquids or sprays; the exhaust manifold is beneath the intake manifold.
 
It can't said enough to be careful with what you spray and where you spray it. Most any spray that will burn (if sucked into the vacuum system) will also burn outside of it. I prefer to use a spray can with a hose on it (contact cleaner or brake cleaner) so I can pinpoint my test area, it's the alcohol that burns, and they evaporate so no residue on your motor.
 
I use a 2 or 3 ft section of old air hose or similar. One end to your ear and use the other end to listen around the area you suspect and move the hose around until the noise increases. You can often pinpoint the leak. This also works well for pinpointing exhaust leaks, pinpointing bearing noises on accessories etc.
 
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I used soapy water to find my manifold leaks. Reversed my shopvac, stuck it on the tailpipe and immediately saw bubbles around the manifold.
 
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