Checking for air leaks

78Jason · 06-19-2003, 12:56 PM

I've been told and read that you use carb cleaner to check for air leaks...

Since I'd be spraying flammable liquid into an enclosed space I want to minimize potential for damage and burns...

What's the best practice / things to look out for? Do I want to spray just the joints where a vacuum line starts/terminates, or spray the whole line in small increments?

Do I want to limit how much I spray per minute, etc...

Many of the lines are hard / if not impossible to spray as they are behind the motor or airbox...

Any pointers will be helpful...

Jason

VincentVega · 06-19-2003, 01:02 PM

I was doing the same thing last night. Make sure you have a fire extinguisher handy, just in case. I found a couple leaks by spraying on the likely aread, at the injectors and on the CIS intake boots. I just sprayed in 2-3 second intervals, dont see any harm in that. I think the ultimate answer for me is to drop the engine and replace as many hoses/gaskets as I find.

tsuter · 06-19-2003, 01:04 PM

You can also use a water mister spray like for household plants. Its a lot cleaner.

91C2wrencher · 91C2wrencher's Garage

tsuter, how does that work? Just plain water in spritz bottle? Enquiring minds have to know.

Joe Bob · Joe Bob's Garage

I'm told propane works as well.

tsuter · 06-19-2003, 01:30 PM

Anything that atomizes well works - Water is just cleaner. No need to worry about nasty fires and explosions.
Oh, the idle drops rather than increases as it would with your carb cleaner or propane - but you probably guessed that.
Some old timers may even remember "water injection" systems.
But that's another story.

Jdub · 06-19-2003, 01:40 PM

So is this where we are with the AAR/AAV/Decel valve question? What became of that?

John

78Jason · 06-19-2003, 02:25 PM

Guys - in this thread about a fire from carb cleaner:
<Engine Fire - Help!!!>
... it says that carb cleaner will melt plastic... will I be creating more problems by doing this?

Lots of people are saying to use water in a spray bottle in both threads... is that truely just as good as carb cleaner? seems to me carb cleaner would be easier to make it's way into a funnel leak than particles of water...

jdub - i'll update that thread when I can do the suggestions from there...I just wanted to start a separate thread for this...

RoninLB · 06-19-2003, 07:50 PM

I use a vacuum leak gizmo that beeps to zoom in on the leak.. it operates on harmonics.. it also works on exhaust leaks..........Ron

masraum · 06-19-2003, 07:57 PM

I would definitely avoid using Carb cleaner, if you get that on anything besides metal it may eat right through. It's really bad for plastic and rubber. Besides it's too flamable to use on a running engine. Water would work, WD 40 might even be better, still flamable, but I wouldn't think quite as potentially harmful to you and your car as the carb cleaner.

Lorenfb · 06-19-2003, 08:16 PM

Please, no propane. Treat your Porsche car with care. We don't want
questions about a "fire melted" intake system.

Good luck
Loren
'88 3.2

David E. Clark · 06-20-2003, 02:23 AM

Ronin,

Please give us more info on your "vacuum leak gizmo." Who makes it? Where did you get it? How does it work? Do you think it works well? As Wrencher said "Enquiring minds have to know."

David
'73 911E Targa

john walker's workshop · 06-20-2003, 07:28 AM

propane is asking for a fireball in your face. carb cleaner eats plastic and takes off paint. oxygen only, from a oxy/acetylene setup works well, and as long as you're not feeding it to an actual fire, it's safe.

RoninLB · 06-20-2003, 09:01 PM

Quote:

Originally posted by David E. Clark

Ronin,
Please give us more info on your "vacuum leak gizmo." Who makes it? Where did you get it? How does it work? Do you think it works well? As Wrencher said "Enquiring minds have to know."

Well Dave.. I over paid from Snap-On.. I've seen the exact same unit sold by others, such as OTC.. and I didn't get the transmitter.. you probe around your engine comp. and the "beep" speeds up.. then you press a button to make it less sensitive as you home in on the leak.. my pro friends said "cool" until they wanted to borrow it.. then it became a "home run".. it's also great for exhaust leaks.. you should pay about $75 from non- Snap-on.....Ron

Lorenfb · 06-20-2003, 10:28 PM

Gee, I thought that I was a tool junky. You guys come up with some
good solutions, away with the carb cleaner.

Good luck
Loren
Systemsc.com

RoninLB · 06-21-2003, 12:23 AM

Quote:

Originally posted by Lorenfb

, away with the carb cleaner.

yeah Loren... it's a cool tool.. had mine for over 5yrs.............Ron

TurboBert · 06-21-2003, 11:17 AM

These things are also sold as "TIF 6500/6501 Refrigerant Leak Detector Ultrasonic w/Transmitter".

The prices seem to range $165-$200. Arizona Tools has them for $165.