REVscene - Vancouver Automotive Forum

toyota86 · 01-03-2011, 02:25 AM

i've been trying to diagnose a vacuum leak on my car for the longest time. tried everything but still couldn't find it. i think my last resort is to use a smoke machine. im looking for some one or some shop with a smoke machine i could use/rent/borrow. i've called around the few shops that i trust to work on my car and none of them have a smoke machine. point me in the right direction. any help would be appreciated.

JSS · 01-03-2011, 02:33 AM

go to long & mcquade and rent one, should be less then 10 bucks for the day.

Manic! · 01-03-2011, 02:36 AM

Check http://www.long-mcquade.com they do rentals.
Jss beat me to it

You can also buy one for around $60.
http://www.axemusic.com/product.asp?...=any&PT_ID=all

MindBomber · 01-03-2011, 02:38 AM

I don't think you need a smoke machine that you would find at a resort or long&mcquade, that would flood your car completely with smoke..

What you could use is a smoke pencil, that emits a small amount of smoke that you could guide over the potential leak points with more accuracy. You can get them online fairly cheap or you might be able to find them at tool stores, DIY stores wouldn't carry them.

TOPEC · 01-03-2011, 03:06 AM

isnt the point in using smoke to find a vacuum leak is fill the whole intake track with smoke and see where it's seeping out?

with ur way of using a smoke pencil and guiding it over potential leaks, why bother with smoke, just spray with soppy water.

MindBomber · 01-03-2011, 03:26 AM

Quote:

Originally Posted by TOPEC

isnt the point in using smoke to find a vacuum leak is fill the whole intake track with smoke and see where it's seeping out?

with ur way of using a smoke pencil and guiding it over potential leaks, why bother with smoke, just spray with soppy water.

It just seemed like a smoke machine would produce a massive amount of smoke for a simple problem, I'm pretty good, but I'm not a mechanic and this may just not be a technique I've heard of.

I have a smoke pencil for work, so when I had a vacuum leak and I just guided over the potential leak points and it took me two minutes to find the problem.

Nightwalker · 01-03-2011, 05:49 AM

There's a few other ways to find it.

You get a can of carb cleaner, use the straw on the end and carefully spray your connections. If the idle changes, then you know you have a leak.

This will work with a light spray of water as well, it's not combustible so your idle will drop/tumble.

Smoke pencil sounds awesome though.

skylinergtr · 01-03-2011, 01:08 PM

as mentioned, you can use intake/carb cleaner and spray around to find a change in idle to detect a vacuum leak.

Otherwise another technique is to have a small propane tank, and open the valve to let the gas out and go around the engine while working. Same method. If the idle changes in an area, there is your vacuum leak.

Best of Luck.

toyota86 · 01-03-2011, 04:56 PM

i've tried the carb cleaner, propane and all that. couldn't find it. there are some spots on the engine that cannot be easily accessed. its a weird design. the smoke machine gives me the option to have the car not running and having air leak out would be easier to trace than trying to put something into the manifold.

PJ · 01-03-2011, 05:44 PM

Are you sure its a vaccuum leak?

bcrdukes · 01-03-2011, 05:45 PM

I had to take my E30 to Nixon Automotive for a vacuum leak diagnoses using their smoke machine. Turns out I didn't have a vacuum leak but instead, one (or more) of my fuel injectors were dead.

They have a Snap-On smoke machine but whether they rent it or not, I doubt it.

some_punk · 01-03-2011, 07:21 PM

I dont think you can use those smoke machines in the earlier links, the smoke machines for automotive use uses nitrogen and something else to generate the smoke. those I think uses water.

MindBomber · 01-03-2011, 07:29 PM

^^^
You are correct, sir.
http://buy1.snapon.com/catalog/item....re&dir=catalog

I have a funny feeling one of the water type ones used for special effects would hydro lock the engine.

dangonay · 01-03-2011, 07:39 PM

Smoke machines work great for vacuum leaks - so great that I'd question any "reputable" shop that didn't own one. I consider it as essential as owning a floor jack or hoist.

Sometimes you can get a leak where it only occurs under certain conditions (like manifold vacuum or temperature). These can be hard to find using carb clean or the like. Really small leaks can be hard as well, unless you plan on dousing your entire engine with carb clean.

Vacuum machines generate smoke under slight pressure, and you use this to pressurize the intake manifold, usually through the fuel pressure regulator line. Even the tiniest of leaks will allow smoke out, and it's such an easy thing to see - and to follow back to the source.

You also have to be wary of things like EGR valves and solenoids. Some of them leak even when new (depending on how they're ported) so don't go and change one just because you're getting a few wisps of smoke from it.

toyota86 · 01-03-2011, 11:27 PM

so, where can i rent/borrow an automotive use smoke machine? recommend me a shop that perform this test? i refuse to bring my car to nixon again. my engine is very prone to vacuum leaks due to its shitty design among other things. i would like to rule it out before looking at spark and fuel.