Help: How to fine intake air leaks?

[Bebop367]

I am trying to find the best way to check for air leaks that could cause high silicon or other high readings in UOA. ANY TIPS WOULD BE APPRECIATED!
I though about spraying the intake ducts, connections and the air intake manifold with starting fluid. My thinking is I should notice engine changes if it is pulling the starting fluid in. The starting fluid will not leave a mess. But I don’t know number one if it will work. Could it possible cause cause damage external or internal? Could some other spray be used? Well if nothing else some of you may get a little humor out of this. Any Tips or Suggestions WOULD BE APPRECIATED!

 

[simple_gifts]

Use propane.

 

[Merkava_4]

Okay, we're talking about some old fashion mechanic's tricks here:

For intake manifold leaks:

1) Spray some kind of combustible liquid around the intake manifold gasket where it meets the heads such as carburettor cleaner or starting fluid. Try to keep it away from any hot surfaces such as exhaust manifolds.

2) As you're spraying around the gaskets, look at your portable tachometer for any sudden increases in engine speed. If there's a leak, the engine will suck in the spray from the source of the leak and burn it in the combustion process as an increase in fuel. If you don't have a tachometer, a portable vacuum gauge can be used. In that case, a decrease in manifold vacuum would equate to an increase in engine speed.

For leaky vacuum hoses:

1) This will cause a lean condition just like an intake manifold leak, but you don't need a spray to check these. All you do is take your nose pliers and start squeezing hoses that lead to the intake manifold. If you squeeze a hose and the idle smoothes out, you've found your leaky vacuum hose.

Air cleaner assembly and air duct hoses:

With these there's not a high enough vacuum source to use any combustible liquid for checking leaks; it's more of a visual check. You want to make sure the air filter seals tightly inside it's air box. You also want to make sure the intake hose fits tightly around the throttle body and air box. Everything between the throttle body and the air filter needs to be sealed tight. Everything before the air filter is not as critical, but you still want that sealed too for good air velocity.

 

[Bebop367]

Thanks for the tips.

I was thinking the ducts may not pull in enough.

Some of the old school still works.
How long since any of us has had to file the point contacts with fingernail (or something) file to get home.