[vbevan]

Hi all,

I'm trying to make a smoke that I can inject into a cars air intake (while it isn't running) to give a visual indication of any where there are leaks in the system. Obviously denser and coloured would be better. I have found a few ways to produce smoke for this, but wanted to know if these would produce any residue that may stay in the system after the smoke has cleared (large particles that may drop as the smoke cools etc.)

White Smoke Recipe

* Potassium nitrate - 4 parts
* Charcoal - 5 parts
* Sulfur - 10 parts
* Wood dust - 3 parts

Red Smoke Recipe

* Potassium chlorate - 15%
* para-nitroaniline red - 65%
* Lactose - 20%

Green Smoke Recipe

* Synthetic indigo - 26%
* Auramine (yellow) - 15%
* Potassium chlorate - 35%
* Lactose - 26%

Does anyone otherwise have any suggestions for a cheap way to produce smoke that won't leave any residue? It will travel through 2-3 meters of car intake until it exits the exhaust.

Thanks.

[Borek]

All those will leave a residue, and TBH I can't think about anything visible and safe that you can use. Can't you just spray the suspected points with soapy water to see bubbling?

[vbevan]

I can, but parts of the engine (this is for a 300ZX btw, though could obviously be used for any car) aren't easily accessible in that way. Also, alot quicker this way as all leaks will show at once. Thanks for the reply anyway.

[enahs]

There are already various products like this on the market. They usually use phospherence and you need a UV lamp or black light to see them. Look around on car repair websites and such to find more info.

[atkray]

As stated there are multiple smoke machines on the market designed just for this most shops will do this check for 30 -70 dollars in Utah.  Soapy solutions are no good as the moisture will frequently swell and seal small leaks, and the solution would also be drawn into the motor which may be undesirable. Also be advised that some components could be damaged by too much pressure.  I'm sorry I do not know what they make the smoke out of(but it smells really good, kind of flowery)  and some of them have UV dye in them and some don't.

I took apart the smoke machine at work today and the cannister that produces the smoke gives no indication as to what is inside. sorry   

An after thought, the modern automobile is fairly tolerant. I would think that most of the ideas you have would leave particles that are smaller than what the air filter would allow so they probably wouldn't cause any harm.   I am a master auto technician so I do know a little about this.