03-13-2012, 03:21 PM
Join Date: Mar 2012
Location: austin, tx
My Ride: 04 M3 Convertible
DYI Smoke Machine
I don't normally register on forums just to put up a single post...but I've been going through the web trying to build a smoke machine for diagnosing a vacuum leak for some time. I found a few useful posts on what people did and the diagram the OP posted...so I went to work.
1) parts you need:
Most everything is from harbor freight to save money:
20oz oil can: $4
compressor regulator: $5
1/4" brass coupling: $2
1/4" quick connect kit: $4
16oz of mineral oil from wally world: $2
used glow plug from my truck: free, but figure no more than $10 bucks if you have to buy new
used 12V battery: old car battery or battery backup (UPS) battery works
wires: need some alligator clips and 16ga wires to run battery to glow plug
compressor: i already have a 60gal standing compressor I used to connect to this. You can use a 10 dollar tire compressor from walmart.
total cost: $17 (if you have an old glow plug and battery) to $60
2) Disassemble the oil can, remove the pump and fittings from the lid, drill the can for oil plug and for the 1/4" NPT air fitting.
3) Attach the glow plug, it should almost touch the bottom of the can so you're not using a lot of oil. Also attach the 1/4" fitting with air regulator and quick connect on the other side. I chose to JB Weld mine in place as the can isn't made of particularly thick metal. If the glow plug dies, I'm going to have to rip it out and JB Weld a new one in place.
I also added RTV under the lid of the can as it didn't have a seal and let that cure at the same time. It unscrews and makes a decent reusable seal.
4) Let cure overnight.
5) Pour in baby oil only to cover the glow plug heating element. The more oil you add, the less smoke you'll get as the oil absorbs the heat and it takes more current to heat the glow plug.
Tighten the lid, connect the compressor and set the regulator to just move a little bit of air. 1-2psi is great.
Connect the battery to the glow plug and watch the smoke start.
WARNING: The can will get hot so carry it by the handle or use gloves or something...basically don't be stupid.
I just finished this last night and I'm still tweaking the amount of oil i use. I definitely see that less oil means more smoke, same goes for air pressure. The smallest amount of air pressure that still moves air provides the most smoke.
Plan to use it to find a vacuum leak tonight, will try and take a video.