N00B Vacuum/Boost leak question...

I’m planning on using/borrowing a smoke machine and filling the system with smoke, and watching to see where it comes out…

my only concern, is what kinda machine to shops use? i was told i could use just a regular smoke/fog machine you use from any like, party city, for example…without any problem.

i dont know much about hydrolocking, but i’d be concerned…since i know fog machines shoot out a mist, dont they? wouldn’t too much of the mist build up and form as water in the intake/engine?

probably not, but i just want reassurance so i dont have to worry too much while doing this…

driving my car without being able to boost is killing me, but i know if i do boost i’ll eventually kill my turbos…so i have to control myself, which is no fun…

I’ve heard that an unlit propane bottle (that is turned on) can help.

Car idling, propane bottle opened but not lit, trace vacuum line with propane nozzle…

engine revs up, you found area of leak.

Definitely not possible to get hydro lock from a fog machine. cars never have to be concerned with that unless your trying to cross a river. Common in atvs, jetskies, ect.

[quote=“fairgentleman Z,post:2,topic:35218"”]

I’ve heard that an unlit propane bottle (that is turned on) can help.

Car idling, propane bottle opened but not lit, trace vacuum line with propane nozzle…

engine revs up, you found area of leak.

[/quote]

i’m an idiot…and you need to explain in more primitive terms exactly the process here…

propane is clear…how would i see it? am i just charging the system with propane? how is that safe at all?

i’ve also heard you can try and coat the lines with soapy water and look for bubbles, but with all the hidden miles of vacuum line under my hood, that would not be time efficient at all

You spray propane around the area you think there is a leak well the engine is running and then if well spraying it causes the engine to rev you know your leak is in that area.

You don’t fill your system with propane :banghead:
You leave your car as it is…
Start it…
Grab your propane bottle…
Open it toward your suspected boost/vacuum leaks…
Your engines vacuum will pull in the propane and begin to idle high…
Leak found.

EDIT: Dave beat me to it.

at that low pressure the amount of gas leaking and coming in will be so small i dout the engine will rev, plus most of the leaks happen while under boost expanding the cracks/joints or breaking a seal. But i have never tried it before. I could see it working if there was a majior leak but if you need to use propane to find it your in enough trouble

[quote=“uKi^riDer_Dzl^drIVer,post:7,topic:35218"”]

at that low pressure the amount of gas leaking and coming in will be so small i dout the engine will rev, but i have never tried it before.

[/quote]

how do you even log in with that SN? thats gotta be annoying

well thats what the “remember me” box would be for. or just look under members and c and p, its really not that bad

:picard:^

[quote=“90NA300ZX”"]

I’m planning on using/borrowing a smoke machine and filling the system with smoke, and watching to see where it comes out…

my only concern, is what kinda machine to shops use? i was told i could use just a regular smoke/fog machine you use from any like, party city, for example…without any problem.

[/quote]

i have a smoke machine that u can use if u want andy

If it’s a bad enough issue to cause a problem with running, usually propane works just fine in finding it.

That said a fog machine is not going to generate near enough water to cause a problem.

if not propane, use carb cleaner in the same manor.

engine rpms will raise when you spray vac leak

when i did charge some air in the plenum itself, i heard a blowing come out under the TPS, which is located on the driverside throttle body…

i’d have to pull the hardpipes off to even get near these vacuum lines, and with them off, there’s no way to do said running tests with carb cleaner, propane, etc. that have been suggested.

i think right now my best bet is to toss some smoke in there and watch by where i think/hope it’s leaking from, and go from there…

there’s at least 3 different vacuum lines i can kinda see down in there, but God knows how many other i’ll find when i pull the TPS and piping off and out of the way…

thanks for all the help thus far guys…

and Jeff, if/when i use your smoke machine, can i just do it at your place? i dont have a garage to work in, and i’m assuming watching for smoke will be very hard working outside…any breeze at all will fuck me over.

[quote=“Dr.Stevil,post:13,topic:35218"”]

if not propane, use carb cleaner in the same manor.

engine rpms will raise when you spray vac leak

[/quote]

While carb cleaner would work, I’d strongly advise against it seeing as it has a tendacy to eat paint, among other things.

[quote=“FuzzyFish,post:15,topic:35218"”]

While carb cleaner would work, I’d strongly advise against it seeing as it has a tendacy to eat paint, among other things.

[/quote]

heh… never knew it ate paint, thats good to know.

I guess it’s propane FTW

oh and for the in-ability to access the lines, why not run a long rubber hose off the tank, so to be able to get in tight areas? Atleast you may be able to isolate the problem line/area

g/l man

so you have no boost at all?

Brian

I have never had any success with the propane/starter fluid/carb cleaner method after many many attempts. Build a boost leak tester and use soapy water on all joints/coupling/adjustment screws/vacuum lines/orings/seals.

[quote=“reliant_turbo,post:17,topic:35218"”]

so you have no boost at all?

Brian

[/quote]

still making plenty of boost…just not holding it perfect…it’ll boost up to 15 psi where it should, then drop to 13 or so, and the gage kinda flutters between 12 and 14 psi through the powerband…

but i haven’t really boosted in a while since realizing i lost vacuum pressure, so i can’t tell you how much boost it would make/hold now.

i already have a tool/fitting that goes in where the stock air filter goes, and it has a tire valve on it to toss air in, and a pressure gage on it to monitor pressure and how fast it drops, but was not successful in using this since i couldn’t build up any pressure at all. i checked the gage, it works fine.

within the next week i’ll be meeting up with TunerFreak and we’ll see if we can get smoke to come out somewhere…shouldn’t be too bad compared to the ridiculous off-the-wall, completely unusual problems i’m use to coming across…

i wouldnt just check the charge pipes. id go over the factory vacuum line diagrams and check for cracked, leaking stuff. alot of times the internal wastegate mechanics get sticky and inconsistent too.

Brian