What is the best way to detect air leak?

[areznik]

Hey guys,

I think that I might have an air leak as I hear extensive hissssing sound somewhere from below upper intake. I read a few posts about using a propane gas but could not find specific instructions on how to do it (if there are other methods to detect it, I think it would be great as well).

Any help or advice would be greatly appreciated,Andre.

[Q451990]

I'm a fan of spraying brake parts cleaner. The idle speed should rise when it's sucked in to the leak as the engine burns off the extra "fuel"

Heath

[DAEDALUS]

Propane gas is used the same way I think. Brake cleaner is nice cause you can actually watch the mist. But chlorinated ones aren't good on plastics. WD-40 works too.

[maxnix]

Propane gas is used the same way I think. Brake cleaner is nice cause you can actually watch the mist. But chlorinated ones aren't good on plastics. WD-40 works too.

Methinks WD-40 is chlorinated also. Percholoroethylene definitiely is, and it is the primary active ingredient in brake cleaner.

[911/Q45]

Some shops have a smoke machine that you blow into the intake and the smoke comes out where the leak is.

[elwesso]

Some shops have a smoke machine that you blow into the intake and the smoke comes out where the leak is.

THis is by far the easiest way.. call and ask if they have a smoke machine...

Be sure to ask if you can come in and watch to see where the leak comes from...

[FarFetched]

That's the way you test EVAP/EGR system for leaks and cracks in hoses. Get a can of "smoke in a can" and "create" slight pressure and inject the smoke!Cheers!

[areznik]

Thanks for the info guys! I will try it probably this weekend and update the thread afterwards. By the way, where can I get that can of "smoke in a can" and where exactly do I inject it in? Should I place is below the air filter?

About spraying brake cleaner, I will try it but unfortunately I have no idea where the lead might be and there are some hoses behind upper intake that are kinda hard to spray on.

I will call a couple of local shops to find out if they have the smoke machine.

Once again thanks for the info, I appreciate it.Andre.

[elwesso]

When i had the "smoker" put on my Q45 (the old Q) they put it on the brake booster hose thing... best to do it that way, it injects it right into the middle of the plenum.

[DAEDALUS]

We had a recent discussion on how to get the same results shadetree-style. zerothread?id=113828