tips for chasing an air leak?

[RUNAMUCK]

One of my fleet of broken down shitters idles like a tanga with a back yard port job. Seems to run Good otherwise, But it's a little jerky off the line unless you give it a gob full. Which Is a pain in the arse since it's supposed to be a luxobarge. The breather hose from the cam cover to the plenium Is Pretty mank. (For some fucked up reason they don't run any valve, and the crankcase see full manifold vaacuum all the time?). I've procured a brand new genuine replacemwnt hose, But not yet fitted it. (I have a gut feeling that isn't gonna be the problem, not sure why)

So id like to have a plan B before I even start trying to Fuck with it.

What Is the proceedure for finding air leaks on an engine?

The motor Is otherwise Pretty grouse.

[Raizer]

Spray some engine start/brake cleaner/other solvents at it and listen for change in idle?

[unhuman]

Spray soapy water around all possible leak points, look for bubbles.

[Lord Gruntfuttock]

Yeah you can chase a leak with something like crc/wd40 sprayed at problem areas and listen to noise change, but messy, best to use butane/engine start...

[Roman]

Spray soapy water around all possible leak points, look for bubbles.

Does this work for vacuum leaks though, or only boost leaks.

 

Wouldnt the bubbles be happening on the inside, haha.

[SOHC]

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[Valiant]

Pinch any vacuum lines that look suspect at the intake manifold with a pair of pliers and see if the idle changes.

Have a good listen around the intake manifold with a piece of vacuum line held up to your ear.

 

Years ago I worked at a place that had a machine that pumped smoke into the intake when the engine wasn't running so you could see where the smoke leaked back out. 

It seemed like a good idea but I never saw it used to solve a problem.

[Yowzer]

Smoke machines are lush for finding air leaks. I've used them heaps on shit German shit that leaks from everywhere.

[Yowzer]

They're a $2,000 piece of kit though so ya might wanna improvise. A weed Wacker running too much caster oil with the exhaust hooked up to the cars intake could do the trick

Or try SOHCs weirdly typed suggestion.

[Yowzer]

Other option, as suggested, spray some engine start or brakleen around different parts until the idle picks up, then pinpoint it with a stethoscope / hose jammed in your ear and find the hissing noise.

[tortron]

Visually inspect the hoses

I bet they are all fucked

Brake clean or pull them off and check for idle change

[governorsam]

[4AGEMAD]

brake clean is my go to 

[SOHC]

I used the hose to locate a bad intake manifold gasket, 4 bad injector seals, and bad sparkplug leads on my volvo,

 

 

I could see it pull the water in around the injectors and manifold gasket , and it stalled when the leads got wet.

[RUNAMUCK]

 on shit German shit that leaks from everywhere.

 

Funny you should say. It was built in Germany. 

 

Another mate said he worked on the same engine once. It had a shit idle. The cam had got fucked, and been reground. Nothing would make it run nice untill the fitted a brand new genuine cam. I'd say mine has had a cam grind since it has zero wear at all on it. I doubt it's been lumpied though. There was nothing stamped on the ends.