How to do a smoke test?

[Waitedog]

Trying to check for vacuum leaks on a 1994 e34 530i with 188k miles:
I made a diy smoke test machine today which uses my air compressor, coffee can and a cigarette.
What I can't seem to figure out though is how to use it effectively.
The engine was off and the car was in park.
I disconnected the main air hose from the air filter and sealed it with a nitrile glove as was instructed in the videos I have seen.
Then I disconnected the vacuum line that goes from the engine to the brake booster.
I put the line coming from my diy smoke machine into the engine block where the brake booster line was and tightened the host clamp securely.
I then lite the cigarette and turned on the air flow from the compressor as what I think was about 7psi.
I ran the diy smoke machine till the cigarette was all consumed and the only smoke I saw was where my hose was connected to the brake booster hose on the engine block. (it was leaking due to my diy adapter I made).

.........But the nitrile glove I used to seal the main air hose going to the throttle body never inflated like I have seen in videos.

I am doing this because I took the car to a BMW repair shop (not a dealer) and they told me they did a smoke test and that I have leaks at the intake manifold gasket.
I want to verify this before I pull off the intake manifold.
So my question is what am I going wrong?
Where should I be connecting the smoke machine to to assure I am testing it accuratley?

Thanks in advance.

[Binjammin]

A cigarette will never produce the volume of smoke you need to find a leak. Real smoke machines use a heated element to vaporize baby oil, there are DIY instructions for building your own, but they're still kind of pricey at that.

In reality, an m60 doesnt have many places to leak vacuum from, and it's cheap easy insurance just replacing them. Intake gaskets and pcv plate.

[Waitedog]

Regarding the minimal amount of places to leak from: that is what I was thinking as well. I don't really see many places/hoses that could leak.
I will just order the gaskets and plate and do it next weekend.
On a scale of 1 to 10 on smashed knuckles, how hard its it to replace the intake manifold gasket and plate?

[Binjammin]

Regarding the minimal amount of places to leak from: that is what I was thinking as well. I don't really see many places/hoses that could leak.
I will just order the gaskets and plate and do it next weekend.
On a scale of 1 to 10 on smashed knuckles, how hard its it to replace the intake manifold gasket and plate?

You'll want to get new bolts and washers for the PCV plate and throttle body also. The factory bolts are torx and are notorious for stripping out. Don't go about it thinking "I'll just be careful" because you'll just strip them anyway and have to run to the store. They're metric bolts obvs, and IIRC they're m7 or m8. You can check them on realoem and just get bolts the same size and thread pitch at any hardware store.

On a 1-10 of smashed knuckles? I'd say a 1 or 2, you're not very likely to injure yourself doing this job. On a difficulty scale, figure 2-3? As long as you keep track of which connectors go where, and just follow the DIYs, you should be fine.

Now, here's the fun part. There's a lot of "while you're in there" you can do at the same time. You can do knock sensors, they're usually like $80 a piece IIRC. There's 4 of them. You'll need to remove the coolant crossover pipes to get them out, which means the rear coolant manifold should come off. There's two gaskets for that, and the crossover pipes have two o-rings each. Since you'd be taking those off, you'll be able to do the valley pan. That and valve cover gaskets would give you a pretty effectively resealed top end.

At the very least though, do the PCV and throttle body gaskets as well as the intake runner gaskets, plus the bolts for all of them.

[SW530]

I have a large shoebox, maybe a bootbox,, size smoke generator that holds nearly a 1/2 of bug juice.. many recipes on the net for making your own. This can fill up the house with smoke so not good for cars, I needed something else small and handy and toolbox size. Toolbox space is always at a premium and despite my diligence they keep multiplying.. Anyway, I ended up buying one exactly like this one. But the one I bought was $15.. Perfect for automotive work. And not likely to ignite gas vapors or anything else..

[rbelton]

That smoke pencil is interesting! I bought one of those $75ish evap smoke tester kits found all over eBay/Amazon. I'm not sure if it can be used on the evap fuel system, but is supposed to be safe for intake leaks. Here's a video demonstration of the smoker machine on my M30 engine found in the E32.



link: https://youtu.be/QIGQGai5ngs