Thinking I have a vacuum leak and want to do a cigar smoke test. I've done several searches for cigar smoke test and although I have found reference to it,.....I have yet to find the actual procedure.

Can Someone point me to it?

Brian In San Antonio

 

Smoke testing is usually done on closed systems under pressure, so you can see the smoke coming out of leaks.

Being careful to have a fire extinguisher on hand, I just use a can of carb cleaner or WD-40 to spray likely points where vacuum might leak. If the engine idle speed increases, that's usually a place where air is hissing through and into the intake system. DO NOT use this method if you have open sparks in the engine bay. DO NOT do this inside a garage. Use common sense.

Here are some articles on the subject that came up with a quick search:

Make vacuum leaks hiss-tory
How to Find a Vaccum Leak
Popular Mechanics article

Good luck,
Scott

 

Unhook the intake at the throttle body (or maybe unhook at the maf, the smoke might be bad for the maf not sure) Be prepared to block the intake hose with something (I’ve used a rubber glove and rubber band) Take the small rubber cap off the port located on the intake, attach a small rubber hose to the port. Light cigar, blow smoke into the intake via the rubber hose until it’s filled. Block the intake hose now with your glove or whatever. Keep blowing smoke into the rubber hose until you see smoke coming out of your leak. You could probably blow compressed air in at a real low psi too

 

I've been meaning to do a smoke test on my V8 for vacuum and SAI piping leaks.
I've seen a few YouTube videos on how to make a smoke machines for cheap but I guess using an old stogy and a hose will do the job too.

 

You can build one with a mason jar, bicycle pump, soldering iron and mineral oil/cotton and a few hoses. Mineral oil and soldering iron is the smoke and heater element, then pressurized air in, and pressurized smoked air out.

 

It's on the right-hand side of the intake, under the port where the brake servo vacuum pipe attaches. Since your truck is an '03 it may have SAI and the port may be occupied by a line to the SAI setup, but I'm not certain of that.

 

Let Scotty show you...

 

This is on a Defender but same V8 engine.
Add a hose at the circled area...

 

The port circled in the pic above is where I was talking about. Even if it has a hose on it for our SAI can't you pull it off and blow the smoke in there?

 

Don’t over think it. Basically pull any hose off that’s attached to the intake. You may have to block that hose too though.