Exhaust Leak Testing

[wagoon]

So I just noticed I have an exhaust leak because I have lost back pressure. What do you guys recommend to use for leak testing besides my nose. I have heard you can use Seafoam is that true. I only used Seafoam on my e30, can you use it on a dime? 

[racerx]

That's what I heard. Have not tried this though.  Have you thought about calling Seafoam itself and see what they say.

[MikeRL411]

I use a very old airliner audio headset, the "pneumatic" kind that plugged into recepticals on your armrest. Two lengths of tubing would do if you shoved them not too deeply into your ears. Pass the end [that's not in your ears] over the exhaust piping. When you hear a poping noise sequentially in the right and left ear [of left and right depending on how you sweep] you have found the leak! Hopefully at a gasketed joint so you don't have to learn how to weld high temp tubing.

[metalmonkey47]

I've used seafoam on an L20B. Worked great for finding leaks.

[Laecaon]

I would be apprehensive to using Seafoam in your non rebuilt motors. It might dislodge something, or clean something, which is now acting like a seal.

[DanielC]

MikeRL411 has got the right idea, but is making it way more complicated.  Just get a piece of garden hose, fuel line, vinyl tube, or something similar, hold one end by your ear, and hold the other end close to the suspected leak.

 

for mechanical noises, you can take a long screwdriver, put the handle on your ear, and the blade on something, like close to an alternator bearing you think is making noise, and isolate noises.

[wagoon]

So any popping type sound should be where the leak is. I'm going to try a stethoscope on the exhaust piping and see what I can hear. Hope this works. How bout the exhaust manifold, how would you listen or detect a leak there? Just listen?

[banzai510(hainz)]

WHAT!!!!!!!!!!

 

How youknow it leaks? It stinks right

Most leaks are at the flange if running the stock cast manifold or the 2 center exhuast ports the intake /exhauset manifold gaskets blow out there.

 

when cold start up motor and put your hand up in there and feel for a Hot gases comming out.

 

if your crank case vent is not hooked up to PVC valave than that could be the stink

[Silky_Johnson]

for mechanical noises, you can take a long screwdriver, put the handle on your ear, and the blade on something, like close to an alternator bearing you think is making noise, and isolate noises.

 

The mental picture that this created for me was some guy leaning into the engine compartment with a screwdriver in his ear getting his hair or face caught in the fan or burned by the exhaust manifold...  :rofl:

 

It goes without saying that a person would have to do this safely.  I was just imagining all of the things that could go wrong, and it made me giggle.

[KyushaKai]

Skip to about 3 minutes if you're lazy.

[wagoon]

I did the rag trick and it sounds like its in the exhaust mani cuz I have broken bolt there. What are the chances of the stock exhaust manifold cracking? Im looking for a header too if anyone has one.