Is this an exhaust leak or is it normal ?

[ErikinSC]

So, driving home tonight, the 2F sounded a little different, the exhaust sounded a bit softer and more flat....

I left the shop, and gave it some gas, but did not develop the power / throttle response I normally get. I could not accelerate as well as normal. I got home, popped the hood and listened.

It sounded like there was an exhaust leaking popping in time with the revs on the motor. I felt under the intake / exhaust manifold, near the heat riser, and sure enough, there is a constant 'puffing' occurring in sync with the engine revs.

Is there supposed to be air pulsing out of the hole for the flapper ? Am I imagining things? Manifold seems really rusty - but I can't see an actual hole.

I don't smoke - so how do I test it? Spray of some sort?

 

[CharlestonG8R]

It's times like this where I wish I could just drive mine over and we could compare them...

 

[dbenke]

There shouldn't be exhaust coming from the flapper, but that is an area where it will leak first.
Mine has a header on it, probably for the same reason, might be time to swap yours.

 

[GLTHFJ60]

"How do you test it"

1. Turn the truck on with the hood open
2. While the truck is running, put your hand down under that area and see if you can feel air coming out of the exhaust manifold

Do it when the engine is cold and for the first few minutes, the exhaust will be cool enough that it won't burn your hand

 

[ErikinSC]

I did that with a hot engine. Used a paper towel to verify exhaust was puffing out in sync with the motor turning over.

I have a huffing and puffing motor. Funny thing is - last night it ran like crap : no power, slow to accelerate, etc. - and 1/8 mile from the house this AM, it suddenly cleared up and started to run absolutely fine. Ugh !

 

[dbenke]

probably unrelated...did you ever get the new distributor in there?

 

[dbenke]

But running bad will make the exhaust leak sound louder

 

[ErikinSC]

probably unrelated...did you ever get the new distributor in there?

Yes, I did. Got it seated and lined up fine the first try. I was paranoid that I wouldn't get it seated fully.

I talked to @beno today - and I will have to pull the intake manifold to inspect - and there are no OEM parts available. So it will be an adapt and modify to repair it. I will try to keep it functional, just want to figure out why it is leaking.

 

[CharlestonG8R]

Yes, I did. Got it seated and lined up fine the first try. I was paranoid that I wouldn't get it seated fully.

I talked to @beno today - and I will have to pull the intake manifold to inspect - and there are no OEM parts available. So it will be an adapt and modify to repair it. I will try to keep it functional, just want to figure out why it is leaking.

Lemme know if you need a 2F intake manifold, I have an OEM that I'm not using.