Question on using a flow gauge for leak testing
Thread Starter
Heel & Toe
Joined: Mar 2020
Posts: 15
Likes: 5
From: Summerville, SC
Question on using a flow gauge for leak testing
I can see the utility of having a flow gauge if you're testing the EVAP system for leaks, or something else that should be a closed system.
But, I was looking into a smoke machine to test for vacuum leaks recently, and I'm not sure if also having a flow gauge is useful for testing that system.
I'm assuming that valve overlap would prevent any kind of meaningful leak flow measurement, but I'm not sure.
If all cylinders are sealed and there's no overlap or other valve sealing issues, then I guess a flow gauge would reveal a leak or leaks in the vacuum system.
If there was overlap, I'd expect the flow gauge would max out.
I'm not sure what I would expect to see if there was, say, a bent/burnt valve, or if it would be discernible from a vacuum leak.
I'm not trying to make this too complicated, I'm sure smoke by itself is enough for most vacuum leak DIY diagnosis. I just started to question my understanding of how sealed the intake/vacuum system is with the engine off.
But, I was looking into a smoke machine to test for vacuum leaks recently, and I'm not sure if also having a flow gauge is useful for testing that system.
I'm assuming that valve overlap would prevent any kind of meaningful leak flow measurement, but I'm not sure.
If all cylinders are sealed and there's no overlap or other valve sealing issues, then I guess a flow gauge would reveal a leak or leaks in the vacuum system.
If there was overlap, I'd expect the flow gauge would max out.
I'm not sure what I would expect to see if there was, say, a bent/burnt valve, or if it would be discernible from a vacuum leak.
I'm not trying to make this too complicated, I'm sure smoke by itself is enough for most vacuum leak DIY diagnosis. I just started to question my understanding of how sealed the intake/vacuum system is with the engine off.
Melting Slicks
Joined: Jul 2003
Posts: 3,499
Likes: 878
From: Saratoga Springs NY
2024 C4 of the Year Finalist - Modified
2022 C4 of the Year Finalist - Modified
Get yourself a good vacuum gauge. Will tell you alot of things. Google vacuum gauge display readings and you'll see what a good gauge can tell you.
