How To: Smoker - To Find Vacuum Leaks

[mluder]

Hello everyone... Something a little different here today. This isn't a how-to aimed at fixing something particular on your DeLorean. Rather it's a how-to to make a device to help you ferret out nagly little leaks in your engine... The dreaded VACUUM LEAK!

Now there are machines available to do this but they are expensive to buy. You may be able to rent one in your area. The third option is presented here - Build your own. I built this one for less than $25. Of course that doesn't include the cost of an air compressor which you will need but there are inexpensive alternatives like the little 12 volt ones that will work just fine.

Here we go...

All the materials you will need.
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(Counter-clockwise starting with the bucket)
2 Gallon paint bucket (It remains to be seen if this will work - It's possible the plastic may be problematic with the heat)
10' of vinyl tubing - 1/2" O.D. x 3/8" I.D.
5/8" Cut washers (I bought 3 but only ended up needing 2)
3/8" x 3/8" Brass adapter
1/2" x 3/8" Coupling flare
1/2" Cut washers (I bought 3 but only ended up needing 2)
1/2" x 1/4" Reducer
1/4" x 1/4" Universal coupler
I'm lucky enough to have a central air system but none of the connections had regulators on them so I bought one. You won't need to if your compressor has an easy to access regulator.

Making the Lid
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As you can see the brass fittings are tapered so we have to make up some slack. That's what the washers are for. They also help make for a tighter seal.
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If you size your drill bit correctly you will have to work to get the fittings in which should help make things nice and sealed.
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Now for the coupler on the bucket.
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And here's how everything looks together.
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...and the new regulator.
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So... from here the idea is to add some sort of combustible to the inside of the bucket. That's what makes the smoke. I have seen it done two ways.

- One involved a charcoal briquette that you heat with a propane torch to get it going. You then place it inside a glass container of some sort and add a few pieces of heavy cardboard on top. The heavy cardboard is slow to ignite so it just smolders and makes smoke. I'm a little concerned with the amount of heat this method makes and how it will affect my plastic bucket. If I had gone with metal it would be less of an issue but I couldn't find a metal can with a lid that was easy to take on and off - a paint can would require a mallet to put on and a screw drive to remove. Could be an issue if the fire got out of hand.

-The other method involves using a wick from one of those backyard tiki torches. You shove it on the end of a soldering iron and soak it in baby oil. The iron heats it enough to get it smoking.

Regardless of the method - the the air enters the bottom of the bucket and exits the top carrying the smoke with it.

That's it for now. I'll be back hopefully some time this weekend with more pics as I test the smoke generating methods and the eventual search for vacuum leaks on my car.

Please stay tuned...

[Citizen]

Great Mcgyverism (http://www.urbandictionary.com/define.php?term=Mcgyverism) there Steven.
Two thoughts I had:

1) Would simply a lit cigarette due for a source of smoke? You just need a little, and you could re-light it when it goes out by itself. Or, how about a hunk of dry ice in the bucket...then just drop room temperature water on it from time to time to keep the smoke coming.

2) I wonder if the air-inlet could have been at the top of the bucket, or even in the lid, same as the output. That way, you preserve the bucket (I guess I'm a cheap dude).

Anyway, I like it, and I'll be interested in seeing your test results.

Thomas

...

[davidc89]

Halloween smoke machine? Those are usually reasonably price. I have always thought about rigging one up to try it. It might cost a little more, but it will save you time and headaches. If you are going to use it on a EVAP system, you will have to use some sort of inert gas. Nitrogen maybe?

[DMC5180]

If you had access to fireworks you could drop in a a colored smoke bomb in the bucket. I think they only burn for about 15 seconds but the smoke is really thick and would be very easy to see.

Another source for air pressure could simply be a hair dryer (heat off) duct taped to the side of the bucket in the event you don't have an air compressor.

[opethmike]

I use this one:

http://www.pontiacbonnevilleclub.com/forum/general-chat/topic35820.html

[Bitsyncmaster]

If you had access to fireworks you could drop in a a colored smoke bomb in the bucket. I think they only burn for about 15 seconds but the smoke is really thick and would be very easy to see.

That is a good idea. I wonder if it would produce it's own pressure also. I will buy some when I go to South Carolina this year.

[DMC5180]

I doubt it would much if any pressure in bucket, a small container (possibly). I just looked at a smoke ball demo video. They only smoked a few seconds which is much less than remembered as a kid. I did see a demo where 5 balls were lit at once. That did produce significant smoke volume that would work well in the bucket.

The good news is that you don't need to go to a state where fireworks are legal. You can get this stuff all day long of the net.

[mluder]

I use this one:

http://www.pontiacbonnevilleclub.com/forum/general-chat/topic35820.html

That's nice... And a good idea to provide the smoke.

Cheers
Steve

[mluder]

Halloween smoke machine? Those are usually reasonably price. I have always thought about rigging one up to try it. It might cost a little more, but it will save you time and headaches. If you are going to use it on a EVAP system, you will have to use some sort of inert gas. Nitrogen maybe?

I would be concerned about the any residues from the chemicals used to make the smoke... that's why I'm not keen on the baby oil method.
I may try a cigar or other tobacco product.

Cheers
Steve

[mluder]

Great Mcgyverism (http://www.urbandictionary.com/define.php?term=Mcgyverism) there Steven.
Two thoughts I had:

1) Would simply a lit cigarette due for a source of smoke? You just need a little, and you could re-light it when it goes out by itself. Or, how about a hunk of dry ice in the bucket...then just drop room temperature water on it from time to time to keep the smoke coming.
I was originally thinking about using a cigar and just blowing from my mouth into the intake but after some research it would seem that is not enough constant smoke and pressure. Still, the idea of using tobacco for the smoke is intriguing.


2) I wonder if the air-inlet could have been at the top of the bucket, or even in the lid, same as the output. That way, you preserve the bucket (I guess I'm a cheap dude).
I have seen it done that way... my concern was making the ting top heavy... The compressor hose is kinda bulky. I could add some ballast to eh bottom - Rocks or even pour a bit of concrete. That would have the added benefit of insulating the heat source from the bottom of the bucket.


Anyway, I like it, and I'll be interested in seeing your test results.

Thomas

...

Cheers
Steven

[Josh]

My brother had issues with vacuum leaks on his jeep. He bought a prop smoke machine for 20$ off ebay. Worked great for him.

[jangell]

I did something similar with a fog machine, using a YouTube video as a guide. Worked pretty well:

https://www.youtube.com/watch?v=rvjk4F9sRo8

-- Joe

[Farrar]

I did something similar using a cheap cigar.

[Rich_NYS]

Where do I connect to put the smoke into the system....right on the tube that comes off the air cleaner box?

[mluder]

Where do I connect to put the smoke into the system....right on the tube that comes off the air cleaner box?

Yep. You need to remove the air filter box and then seal up the fixture regulator opening. I used several layers of blue painters tape. Be thorough... my first attempt allowed air to escape and I though I had some massive leak in the mixture unit.
You then connect your smoke feeder hose to the hose coming out of the oil filler cap that was attached to the air box. You may also want to find a way to fix down the oil filler cap as it will want to pop out when you put pressure into the system.

Cheers
Steven

[mluder]

As this thread has popped up again I thought I'd better provide an update.

I smoke tested my engine a couple of weeks ago and the results were inconclusive. Mostly due to an issue with smoke generation.

I tried using an piece of charcoal briquette and heavy cardboard which would smolder but not ignite. The glass jar that I put it in inside the bucket got too hot a cracked but did not break.
At any rate... I got smoke but it would not sustain itself for an appreciable amount of time. Next test I think will be using some sort of oil and wick. I may try this weekend.

Stay tuned...

Cheers
Steven

[Bitsyncmaster]

I still like the smoke bomb idea (just make a jar with a hose). I would think you would get good pressure and I would just have that hosed to the nipple on the back of the intakes. You need to tape your intake plate closed and do the test at night with a flashlight in hand to find the leaks.

[DMC5180]

I still like the smoke bomb idea (just make a jar with a hose). I would think you would get good pressure and I would just have that hosed to the nipple on the back of the intakes. You need to tape your intake plate closed and do the test at night with a flashlight in hand to find the leaks.

It was only an idea that has yet to be tested. I did look up some YouTube videos to see what amount of smoke those smoke balls put out. It was pretty wimpy. Nothing like I remember as a kid 40 years ago. But if you were to use the jar as a reservoir and two hoses. You could blow into one hose and force the smoke out the other hose.

[Bitsyncmaster]

It was only an idea that has yet to be tested. I did look up some YouTube videos to see what amount of smoke those smoke balls put out. It was pretty wimpy. Nothing like I remember as a kid 40 years ago. But if you were to use the jar as a reservoir and two hoses. You could blow into one hose and force the smoke out the other hose.

I will look what can be bought this summer but I think you can get smoke bombs for radio controlled airplanes which may be larger than we need.

[Rich_NYS]

Thanks for the input...I used a cigar and blew smoke into it like a madman. I did consistently see smoke around the bottom of the black cylinder-looking thing with the electrical connector on top. It has a small 90-degree hose on the bottom that appeared to have smoke leaking from it. It seems like the clamps need to be tightened, but I first sprayed starting fluid & choke cleaner around it but it didn't make the engine race. I'll try tightening the clamps & see if that makes a difference.

[Jack]

Thanks for the input...I used a cigar and blew smoke into it like a madman. I did consistently see smoke around the bottom of the black cylinder-looking thing with the electrical connector on top. It has a small 90-degree hose on the bottom that appeared to have smoke leaking from it. It seems like the clamps need to be tightened, but I first sprayed starting fluid & choke cleaner around it but it didn't make the engine race. I'll try tightening the clamps & see if that makes a difference.

You talking about the Idle Speed Motor/Regulator?

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[Rich_NYS]

You talking about the Idle Speed Motor/Regulator?

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Yes sir...thanks for the pic. Both of the clamps on the angled hose were loose.

I'm working on two things at once so I unfortunately haven't been able to start it again to see if there's improvement. I expect to be able to start it tonite after replacing a cooler line.

[Rich_NYS]

Yes sir...thanks for the pic. Both of the clamps on the angled hose were loose.

I'm working on two things at once so I unfortunately haven't been able to start it again to see if there's improvement. I expect to be able to start it tonite after replacing a cooler line.


I have things back together and started the car. I noticed an improvement, but it's not 100%.

I borrowed a dwell meter to check the CO....that'll be tomorrow's mission.

[Trstno1]

My brother had issues with vacuum leaks on his jeep. He bought a prop smoke machine for 20$ off ebay. Worked great for him.

Is there an issue with using the prop smoke machines since the fluid is water based?