Check for exhaust leaks by pressurizing?

[Kimodc]

I saw on YouTube yesterday someone was checking for exhaust leaks by adding pressure to his exhaust system by switching his vacuum hose on his shopvac to the exhaust outlet and then shoving the hose in the tailpipe. He then simply sprayed down all his exhaust joints with soapy water and looked for leaks, similar to checking for leaks in a tire. For a dual tailpipe situation, you stopper the other tailpipe. This looked like a ridiculously easy way to check for leaks without working around a hot exhaust system. Are there any dangers to your engine in doing this? I can see where a valve or two may be open into the heads at any given rotation of the engine, but it is not like there is much air flow that will be carrying particles, more just air condensing and building to pressure. I don’t want to risk damaging my engine, but it sure looks like an easy way to check for leaks…….am I missing something?….. What are your thoughts?

 

[Durandal25]

Why? Super odd, but I guess some folks really worry about that

 

[Kimodc]

If you mean “why?” check for exhaust leaks, it’s because I cobbled together and exhaust system and it sounds like it is leaking. Not sure why that is “super odd”?

 

[WileERobby]

Why not just check for the source of the sound ? That's where the leak is.

 

[Durandal25]

If you mean “why?” check for exhaust leaks, it’s because I cobbled together and exhaust system and it sounds like it is leaking. Not sure why that is “super odd”?

It’s a point to point system designed to exhaust to the rear, but build up in the interior is really the only issue. If it’s leaking near the heads then that could be a problem for safety ….leaks under the car not so much unless you have a lot of idle ect. Is it noisy?

 

[dadsbee]

Get under it while running and run your hand around each joint, it's that simple.

 

[RemCharger]

If you want to get hi-tech like every ancient exhaust shop, have someone plug the tailpipe while checking the joints.

 

[khryslerkid]

 

[Carcinogen]

Also try using a hose, hold one end to your ear while poking the other end around exhaust pipes.

For tracing internal engine ticking, use a long screwdriver and hold handle against ear while other end is on engine.

 

[chtampa]

In the past potatoes were used.

 

[WileERobby]

In the past potatoes were used.

 

[mopar 3 B]

In the past potatoes were used.

If you didn't have a leak you soon would have one unless you got off lucky and the engine died.

 

[kiwigtx]

https://youtube.com/shorts/yTFyRS1p5hs

 

[khryslerkid]

https://youtube.com/shorts/yTFyRS1p5hs

Al Jolson, Mammy!

 

[Dave P]

That's actually a fairly common way of checking for exhaust leaks on piston engine aircraft. Lots of single engine planes use
a heater "muff" around the exhausts to supply cabin heat so carbon monoxide can be an issue.

 

[eldubb440]

there is always a couple open exhaust valves, not sure how you could successfully pressurize the exhaust system

 

[mopar 3 B]

there is always a couple open exhaust valves, not sure how you could successfully pressurize the exhaust system

Guess one could wrap their lips around the carb creating a seal. Appears to be a stupid way to check for leaks when there is a much bigger air pump already at the intake part of things.

 

[Daves69]

In the past potatoes were used.

Here I thought it was bananas!
.......

 

[chtampa]

Here I thought it was bananas!
.......

Perhaps you have been throwing a banana down an exhaust pipe too long.

 

[mopar 3 B]

Drive that patato in there hard and far. The leak will be found in short order. But expect a good boom to go with it. Now we have a leak.