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Q: An exhaust leak on 1994 Chevy V8 with idling

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I've got an exhaust leak on a ‘94 Chevy V8. I've checked the exhaust pipe, no leaks, and I couldn't feel where the gas was coming from. Could that be an intake manifold? Also it idles a little higher than normal. Any advice?

In the intake manifold, you’re not going to get exhaust leaks because that’s the intake. All the systems there are the stuff that’s coming in, not the stuff that’s coming out of the exhaust.

You can hear the exhaust leak. You might try my old trick. I’ve got a video called ’’Finding engine vacuum leak with a cigar.’’ You basically get a cigar, you blow it to any of the vacuum lines and if there’s leak somewhere in the system, the smoke’s coming out. In that case, you blow it in the exhaust in the back, as somebody blows smoke in the exhaust and wherever the leak is--you are going to see smoke coming out, because the smoke comes out of holes. You might give that a try.

I’m a professional mechanic, of course when I do it--I use a smoke machine which is easier. I just plug that in the exhaust and it fills the exhaust with the smoke and I can see where it’s leaking when the smoke comes out. They did that in 1700s to find the sewer leaks in houses. They would blow smoke in the sewer system and see where the smoke was coming out. Though this may be considered unconventional now, it’s a pretty tried-and-true system.

If you’d like, your best bet may be to have a certified technician look at your system. They will be able to diagnose your leak and come up with the appropriate repairs for your vehicle.

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