dewfall

Hello forum. Ever see those testers that inject some kind of smoke into the intake tract of an engine (not running) to identify vacuum leaks? The idea is that the smoke will leak from anyplace not sealed and you've found your vacuum leaks. Apparently it's better to have one that pressurizes the smoke/air to find leaks that only occur at higher than atmospheric. They must be pretty good diagnostic tools because they go for $500 - $2000.

I was wondering if anyone had created their own for cheap and how you did it. Just something for personal use. Being that it's close to July 4 I thought about just lighting a smoke bomb inside the intake manifold and sealing it up lol, but I don't want to damage anything either

Let me know what you think. Thanks

383vett

I made a plate that seals onto the plenum in place of the throttle body. To check for a vacuum leak, I backed off the intake valves and applied a mityvac to the fitting so see if the system held vacuum (gotta plug the port for the brake booster). If vacuum doesn't hold, smoke can be injected through the port. Fortunately, I didn't have to go that far.

bwiencek

What about using one of the cheap Halloween smoke effects generators (fog machine - about $40 at discount stores or less after halloween) and then plumb that into some sort of fan contraption that could build a bit of pressure (I am thinking some sort of fan like a boat bilge pump - but it would have to be able to build some pressure)

SJW

For some time now, I've been contemplating trying to build my own smoke generator for chasing down vacuum leaks. I haven't done it yet, but my plan has been to try installing two hose barbs into the lid of a glass mason jar, with one of them set up to receive the butt-end of a cigarette on the inside end.

The idea being to get the cigarette burning, screw the lid onto the jar, feed low-pressure air into the fitting that doesn't have the cigarette mounted in it, and connect the smoky outlet fitting to the intake tract of the car. I'd first try an aquarium air pump to see if it generates enough pressure to do the job.

Let us know what you try, and how it works. Seems to me a DIY smoke tester need not cost $500.

Live well,

SJW

Alan Lanni

Try checking with a plumbing or A/C supplier (maybe Home Depot) for a can of smoke. We use this for checking leaks, not very expensive.